Volume 20 (2000)
 RNCSE 20 (1-2): Special double issue. |
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 RNCSE 20 (3) |
 RNCSE 20 (4) |
 RNCSE 20 (5) |
 RNCSE 20 (6) |
RNCSE 20 (1–2)
Articles available online are listed below.
A Review of Of Pandas and People as a Textbook Supplement
Throughout the country, school boards are receiving offers of free or low-cost copies of the supplementary textbook, Of Pandas and People: The Central Question of Biological Origins, by Dean Kenyon and Percival Davis. NCSE member Gary Bennett completed a comprehensive review of Pandas last fall to assist the Idaho Department of Education in its decision on whether to adopt the book as a recognized classroom resource. We present to RNCSE readers this abbreviated version of his review to accompany the annual bibliography by Frank Sonleitner listing recent scientific research that addresses the issues raised by Pandas.]
Science is based on finding natural explanations for why the universe works as it does. Pandas invokes a supernatural belief called "intelligent design" (which looks like nothing more than the latest manifestation of the discredited belief system known as "creationism") to explain the origins of life and the creation of the different species of life. Since science does not deal with the supernatural, because it is beyond measurement, Pandas does not qualify as a science textbook.
Scientific Contents
Instead of using the scientific method, what Pandas has done is to produce what philosophers call a "closed system". As the thinker and writer Arthur Koestler wrote:
The theory of evolution would be overturned tomorrow if scientifically verifiable information were uncovered showing that humans lived alongside dinosaurs. The notion of "intelligent design" cannot be falsified, however, because, if confronted with evidence against their belief, the advocates will simply shrug and say, "Well, that is how the intelligent designer did it".
Pandas does not relate well to real life issues such as biomedical concerns. For example, many in the scientific and medical communities are worried about the ever-evolving bacteria around us. Scientists find that bacteria are evolving immunity to the antibacterial medications that have been developed to control them. If we are going to survive, we need to understand evolution, because it describes how bacteria and other organisms change and it describes how our genetic makeup came to be. To teach "intelligent design" is little different from teaching shamanism as a way to eliminate diseases, since it does not engage the scientific method and prior scientific knowledge to understand and solve problems in human society.
Pandas is based on the assumption that evolution and "intelligent design" are competing theories. Nothing could be farther from the truth. As a working scientists, I am not aware of any serious scientific work being done on so-called "intelligent design". The fact that evolution has occurred is accepted by most qualified scientists, whose views are based upon thousands of research results in such diverse fields as anthropology, astronomy, biology, physics, chemistry, and geology.
The theory of evolution, which is a well-substantiated scientific explanation for what has occurred, deals with changes in organisms with time:
Evolution: change in the hereditary characteristics of groups of organisms over the course of generations (NAS 1998).
The above definition was given in the publication Teaching About Evolution and the Nature of Science, published by the National Academy of Sciences, the nation's premier science organization (chartered by Congress in 1863). (Note: The glossary on pages 149-51 of Pandas needs to be corrected to coincide with accepted definitions.)
The theory of evolution is silent on how life originated and it makes no claims about religious beliefs. The fact that evolution has occurred is evident from the fossil record, which is a long record of modifications in the characteristics of animals and plants from the simpler to the more complex over hundreds of millions of years. Scientific work in such diverse fields as astronomy, geology, physics, chemistry and biology overwhelmingly supports the theory that life has evolved on the earth.
Pandas never really provides a scientific definition of "intelligent design". On page 14, Pandas states that "[i]ntelligent design, by contrast, locates the origin of new organisms in an immaterial cause: in a blueprint, a plan, a pattern, devised by an intelligent agent". But nowhere does Pandas provide a scientifically testable definition or theory of the "intelligent agency". What properties does it have? How would a scientist detect it? What measurements could be made? What predictions could be made?
On pages 99-100, Pandas states that "[i]ntelligent design means that various forms of life began abruptly through an intelligent agency, with their distinctive features already intact-fish with fins and scales, birds with feathers, beaks, and wings, and so on." But this is contrary to the fossil evidence. For example, Pandas states that "[n]o creatures with a partial wing or partial eye are known", yet in Padian and Chiappe 1998 we find the so-called "partial wing" in Archaeopteryx and its relatives, and in Pennisi and Roush 1997 we find a summary of some evolutionary studies indicating that the ancestral bilateral animal may have had a simple photoreceptor. Using the "partial eye" argument has been an old favorite erroneous criticism offered by creationists, who do not seem to recognize that any light-sensitive organ would give an animal an advantage over its blind companions. Dawkins (1986) gives a good discussion about how an eye could evolve. Even Darwin, despite the limited knowledge of the fossil record of his day, gave a good explanation of how the eye might have developed (Darwin 1859/1979). Finally, it should be noted that hundreds of thousands of the single-celled amoeba named Dictyostelium have been observed coalescing into something that resembles a multicellular creature with some amoebas acting as eyes (Zimmer 1998). It is surprising that the Pandas authors are continuing to advance objections refuted long ago.
However, what is perhaps worse about pages 99-100 is that Pandas puts itself into the discredited camp of abrupt creation, that is, with those who believe the earth is only 10 000 years old and that every kind of plant and animal was created at once with no changes since (see also page 92). The fossil and geological record clearly shows the earth is older than 10 000 years and that whole species have evolved and died out-there have been fantastic changes!
On page 150, Pandas defines "intelligent design (cause)" as "[a]ny theory that attributes an action, function, or the structure of an object to the creative mental capacities of a personal agent. In biology, the theory that biological organisms owe their origin to a pre-existent intelligence". There are a number of problems with this definition, beginning with the fact that it is a circular definition, i.e., it defines "intelligent design" in terms of itself. What is a "personal agent"? Secondly, "intelligent design" is not a theory in any sense of the word in the field of biology. The National Academy of Sciences defines "theory" as "[i]n science, a well-substantiated explanation of some aspect of the natural world that can incorporate facts, laws, inferences, and tested hypotheses" (NAS 1998). "Intelligent design" fails this definition.
Finally, given the definition on page 150 and the discussions on pages 14 and 99-100, the reader is left in total confusion. Are the authors of Pandas talking about "intelligent design" or an "intelligent agency" or a "personal agent" or a "preexistent intelligence"? Pandas is so confused and circular in its reasoning that it clearly does not meet the test of a good science book; however, it would fit in nicely in a comparative religion class or a class on investigating pseudoscience and the uses of propaganda.
The crux of the issue is that so-called "intelligent design", which has been described as one of the latest evolutions of the ever-evolving creationist movement, is based on supernatural intervention. In effect, "intelligent design" assumes that God was involved at various points in the evolutionary process, but it provides no evidence in support of this belief. Given that the Catholic Church and the mainstream Protestant community have accepted evolution as the way God created the millions of species, one wonders why the creationists still insist upon a literal reading of Genesis. Theologian Langdon Gilkey has stated that creationists come "very close, yes, very close indeed to the first, and worst, Christian heresy!" (emphasis in original) because they try to separate the act of creation from God as if there were two gods, which was the heretical position of the Gnostics (Gilkey 1985). Thus, not only is creationism or "intelligent design" bad science, it is also arguably bad theology!
Professor of philosophy and zoology Michael Ruse has written this about Pandas:
"Intelligent design" suffers from a fatal philosophical flaw:
Presumably the intelligent designer is not so intelligent!
The premise of Pandas is the faulty notion that science should proceed from the supernatural to the natural. Science, by definition, is based on studying the natural world. We do not have Hindu science or Mormon science or Catholic science or Protestant science; we just have science. If the apparently fundamentalist-inspired Pandas is allowed into the classroom, then every religious group can claim with equal justification to have its books included too.
In the 1982 Arkansas court case on teaching creationism (Rev Bill McLean et al. v. Arkansas Board of Education), Judge William R Overton defined science in his ruling against the teaching of creationism (Gilkey 1985; Pennock 1999):
"Intelligent design" fails these tests. Furthermore, Overton (and others) found that "intelligent design" promotes a particular sectarian view in violation of the First Amendment.
Pandas co-author Percival Davis has exposed his biblical literalist bias in a book (A Case for Creation) that he wrote with Wayne Frair: "We accept by faith the revealed fact that God created living things. We believe God simultaneously created those crucial substances (nucleic acids, proteins, and so on) that are so intricately interdependent in all of life's processes, and that He created them already functioning in living cells" (quoted in Pennock 1999, 162). The notion that God operated in an evolutionary way (as accepted by the Catholic Church, mainstream Protestant churches, and various American Jewish organizations) seems not to have affected Davis.
The other co-author, Dean Kenyon, was "an erstwhile origin of life researcher who became discouraged about the whole field and subsequently [lent his name in support of YEC [young-earth creationist] activism..." (Pennock 1999, 162). With no scientific support, Pandas tries to be both "young earth" and "old earth" (see page 92). Young-earth creationists believe that the earth along with the entire universe was created 6000 to 10 000 years ago. To date, there is no recognized scientific support in any field of science for such a belief. There have been many years of student complaints about Dean Kenyon's teaching at San Francisco State University, mainly centered on allegations that he is more interested in what amounts to religious proselytizing than in teaching peer-reviewed biology (Scott 1994). From the foregoing, one would suspect that if Pandas were adopted in biology classes, the next step would be to insist that anthropology, geology, physics, chemistry, and astronomy courses be changed to fit with a literal interpretation of the Bible.
Professor Douglas J Futuyma summed up the issue best with his observation:
Finally, by assuming that life originated by "intelligent design", Pandas opens up a number of questions it fails to answer, such as "Who or what is the intelligent designer?" and "Who or what created the intelligent designer?"
Using the arguments in Pandas, one could equally well support the view advanced by the Raëlian Movement "that intelligent aliens landed here millennia ago in spaceships and formed all of life on earth, including human beings, using highly advanced genetic engineering" (Pennock 1999, 234). If one put Pandas in the classroom, in fairness one would also have to put in the Raëlian book The Book That Tells The Truth. As Professor of Philosophy Robert T Pennock has observed, if we allow Pandas, we would also have to allow "textbooks that advocate Claude Vorilhon's Raëlian model, the Swami Prabhupade's cyclical Hindu model, and so on. As they say, this way lies madness" (Pennock 1999, 368).
Pandas tries to bias the reader by the choice of words the authors use to describe the two positions they discuss. Scientists are referred to as "Darwinists" as if to say that all scientists are followers of some religious guru named Darwin. In light of new information, evolutionary science has moved beyond Darwin's original ideas and so scientists working in the field of evolution should properly be referred to as "scientists". Using the verbal tactics of the authors of Pandas, one would have to refer to advocates of "intelligent design" as "Morrisites" (in acknowledgment of the biblical literalist Henry M Morris who was instrumental in founding the modern fundamentalist belief known as creationism or "intelligent design").
Perhaps Kevin Padian, Professor of Integrative Biology and Curator in the Museum of Paleontology at the University of California, Berkeley, said it best:
The complete list of references is contained in the longer "Review of the book Of Pandas and People: The Central Question of Biological Origins (second edition)" by Gary L Bennett, which will be available soon on The Textbook Letter web site. Other reviews of Pandas from The Textbook League are available on line at.
Consistency with Department of Education Position Statement on Science
The book Of Pandas and People (hereafter, Pandas) is inconsistent with the Idaho position statement on science, which bases its acceptance decisions on the publications of the American Association for the Advancement of Science (AAAS) and the National Science Teachers Association (NSTA). Both the AAAS and the NSTA have consistently supported the teaching of the scientifically accepted theory of evolution. In contrast, under the guise of an alternative approach known as "intelligent design", Pandas does little more than attack the theory of evolution. I was unable to find any peer-reviewed scientific literature on the "theory of intelligent design" either cited in the text or in professional scientific research journals. Furthermore, published work dealing with "intelligent design" by the authors of Pandas has not been found in respected science journals. Since legitimate scientists are not working on so-called "intelligent design", this book should not be used in any science class.Consistency with State Exiting Standards
By attacking the theory of evolution, Pandas fails to support Idaho's draft high school exiting standards:- Unifying Concepts of Science, Section I.D of the Science Standards, states that "[t]he student will demonstrate an understanding of the process of evolution as it relates to the gradual changes in the universe and of equilibrium as a physical state".
- Section V (Interdependence of Organisms and Biological Change) states that "[t]he student will understand the theory of biological evolution" and that "[t]he student should explain the interdependence of organisms".
Science is based on finding natural explanations for why the universe works as it does. Pandas invokes a supernatural belief called "intelligent design" (which looks like nothing more than the latest manifestation of the discredited belief system known as "creationism") to explain the origins of life and the creation of the different species of life. Since science does not deal with the supernatural, because it is beyond measurement, Pandas does not qualify as a science textbook.
Scientific Contents
Does the book provide accurate, reliable, scientific information?
No. Instead of utilizing peer-reviewed scientific information from the accepted science journals (for example, Science and Nature) and a wealth of literature on the best and most current scientific thinking, Pandas engages in sophistry to advance its agenda. In Suggested Reading/Resources, it tends to cite discredited creationist books. The book uses quasireligious arguments and special pleading to try to discredit the theory of evolution. Many of these arguments attack historical science (for example, Oparin's hypothesis, the Miller-Urey experiment, and so on) and are therefore outdated. The authors of Pandas seem unaware of the tremendous strides that have been made in biology.Does the book present scientific theory?
No. The authors provide no scientific documentation for the claim that "intelligent design" is an alternative to the accepted theory of evolution. The National Academy of Sciences, America's premier scientific body, has defined "theory" as "[i]n science, a well-substantiated explanation of some aspect of the natural world that can incorporate facts, laws, inferences, and tested hypotheses". Since "intelligent design" is not well-substantiated in the accepted scientific literature, it does not qualify as a scientific theory.Is the scientific method emphasized?
No. Although there is no rigid definition of the scientific method, one can say in general that it is a way of thinking in which hypotheses are tested against systematic observations of the natural universe. Classically, the scientific method is often defined as a process or method in which a problem is identified, relevant data are gathered, a hypothesis is formulated on the basis of these data, and the hypothesis is then empirically tested. This can be done by conducting laboratory experiments and/or gathering information (such as collecting fossils or observing stars). Critics or skeptics of the hypothesis should be able to conduct their own experiments or make their own scientific observations to test the hypothesis. Pandas fails to use the scientific method; instead, it appeals to an unidentified supernatural agent.Instead of using the scientific method, what Pandas has done is to produce what philosophers call a "closed system". As the thinker and writer Arthur Koestler wrote:
A closed system has three peculiarities. Firstly, it claims to represent a truth of universal validity, capable of explaining all phenomena, and to have a cure for all that ails man. In the second place, it is a system which cannot be refuted by evidence, because all potentially damaging data are automatically processed and reinterpreted to make them fit the expected pattern. The processing is done by sophisticated methods of casuistry, centered on axioms of great emotive power, and indifferent to the rules of common logic; it is a kind of Wonderland croquet, played with mobile hoops. In the third place, it is a system which invalidates criticism by shifting the argument to the subjective motivation of the critic, and deducing his motivation from the axioms of the system itself ... In fine, the mentality of a person who lives inside a closed system of thought ... can be summed up in a single formula: He can prove everything he believes, and he believes everything he can prove. The closed system sharpens the faculties of the mind, like an over-efficient grindstone, to a brittle edge; it produces a scholastic, Talmudic, hair-splitting brand of cleverness which affords no protection against committing the crudest imbecilities.
The theory of evolution would be overturned tomorrow if scientifically verifiable information were uncovered showing that humans lived alongside dinosaurs. The notion of "intelligent design" cannot be falsified, however, because, if confronted with evidence against their belief, the advocates will simply shrug and say, "Well, that is how the intelligent designer did it".
Is the learning experiential? How does it relate to real life issues?
The learning is not experiential. Pandas provides no scientifically conclusive experiments that could be performed to prove that an intelligent designer exists. Worse, putting a religiously inspired textbook into a good science class where students are taught to question orthodoxy would expose the narrow religious views in Pandas to the kind of sharp questioning that could undermine the religious beliefs of some students.Pandas does not relate well to real life issues such as biomedical concerns. For example, many in the scientific and medical communities are worried about the ever-evolving bacteria around us. Scientists find that bacteria are evolving immunity to the antibacterial medications that have been developed to control them. If we are going to survive, we need to understand evolution, because it describes how bacteria and other organisms change and it describes how our genetic makeup came to be. To teach "intelligent design" is little different from teaching shamanism as a way to eliminate diseases, since it does not engage the scientific method and prior scientific knowledge to understand and solve problems in human society.
Should the book be adopted?
Absolutely not! This book does not teach science; it misrepresents science. Students and teachers without a good grounding in biology and the methods of science could be seduced by this book into rejecting well-established science. It is nothing more than a cleverly-worded tract espousing an unscientific belief system. Rather than teaching students how to think objectively, this book teaches students how to twist words and quotations to advance unsupported suppositions. On a more practical level, most biology courses spend very little time on the origins of life so there is no need for a separate book on that subject. And if a separate book on origins is desired, it should be a real science book.Additional Overall Comments
This book suffers from an inordinate focus on the origins of life, which is usually a small part of any introductory biology course. Since most biology courses focus on cells, plants, animals, and their constituent parts, it is not clear that this book would be a useful supplement. In the areas of known science, it adds nothing new, and in the area of the origin of life, despite its protestations otherwise, it advances a particular religious belief under the rubric "intelligent design". There is no peer-reviewed scientific work in the standard scientific literature that supports the assertions of this book. In short, this book follows the cliché-ridden creationist approach of attacking evolution while providing no scientific work to support its position. Saying that an intelligent designer did something that cannot be explained says nothing. People once said that an intelligent designer caused thunder and lightning and the motion of the planets. "Intelligent design" is a mystical, Dark Ages, anti-science philosophy trying to disguise itself as science.Pandas is based on the assumption that evolution and "intelligent design" are competing theories. Nothing could be farther from the truth. As a working scientists, I am not aware of any serious scientific work being done on so-called "intelligent design". The fact that evolution has occurred is accepted by most qualified scientists, whose views are based upon thousands of research results in such diverse fields as anthropology, astronomy, biology, physics, chemistry, and geology.
The theory of evolution, which is a well-substantiated scientific explanation for what has occurred, deals with changes in organisms with time:
Evolution: change in the hereditary characteristics of groups of organisms over the course of generations (NAS 1998).
The above definition was given in the publication Teaching About Evolution and the Nature of Science, published by the National Academy of Sciences, the nation's premier science organization (chartered by Congress in 1863). (Note: The glossary on pages 149-51 of Pandas needs to be corrected to coincide with accepted definitions.)
The theory of evolution is silent on how life originated and it makes no claims about religious beliefs. The fact that evolution has occurred is evident from the fossil record, which is a long record of modifications in the characteristics of animals and plants from the simpler to the more complex over hundreds of millions of years. Scientific work in such diverse fields as astronomy, geology, physics, chemistry and biology overwhelmingly supports the theory that life has evolved on the earth.
Pandas never really provides a scientific definition of "intelligent design". On page 14, Pandas states that "[i]ntelligent design, by contrast, locates the origin of new organisms in an immaterial cause: in a blueprint, a plan, a pattern, devised by an intelligent agent". But nowhere does Pandas provide a scientifically testable definition or theory of the "intelligent agency". What properties does it have? How would a scientist detect it? What measurements could be made? What predictions could be made?
On pages 99-100, Pandas states that "[i]ntelligent design means that various forms of life began abruptly through an intelligent agency, with their distinctive features already intact-fish with fins and scales, birds with feathers, beaks, and wings, and so on." But this is contrary to the fossil evidence. For example, Pandas states that "[n]o creatures with a partial wing or partial eye are known", yet in Padian and Chiappe 1998 we find the so-called "partial wing" in Archaeopteryx and its relatives, and in Pennisi and Roush 1997 we find a summary of some evolutionary studies indicating that the ancestral bilateral animal may have had a simple photoreceptor. Using the "partial eye" argument has been an old favorite erroneous criticism offered by creationists, who do not seem to recognize that any light-sensitive organ would give an animal an advantage over its blind companions. Dawkins (1986) gives a good discussion about how an eye could evolve. Even Darwin, despite the limited knowledge of the fossil record of his day, gave a good explanation of how the eye might have developed (Darwin 1859/1979). Finally, it should be noted that hundreds of thousands of the single-celled amoeba named Dictyostelium have been observed coalescing into something that resembles a multicellular creature with some amoebas acting as eyes (Zimmer 1998). It is surprising that the Pandas authors are continuing to advance objections refuted long ago.
However, what is perhaps worse about pages 99-100 is that Pandas puts itself into the discredited camp of abrupt creation, that is, with those who believe the earth is only 10 000 years old and that every kind of plant and animal was created at once with no changes since (see also page 92). The fossil and geological record clearly shows the earth is older than 10 000 years and that whole species have evolved and died out-there have been fantastic changes!
On page 150, Pandas defines "intelligent design (cause)" as "[a]ny theory that attributes an action, function, or the structure of an object to the creative mental capacities of a personal agent. In biology, the theory that biological organisms owe their origin to a pre-existent intelligence". There are a number of problems with this definition, beginning with the fact that it is a circular definition, i.e., it defines "intelligent design" in terms of itself. What is a "personal agent"? Secondly, "intelligent design" is not a theory in any sense of the word in the field of biology. The National Academy of Sciences defines "theory" as "[i]n science, a well-substantiated explanation of some aspect of the natural world that can incorporate facts, laws, inferences, and tested hypotheses" (NAS 1998). "Intelligent design" fails this definition.
Finally, given the definition on page 150 and the discussions on pages 14 and 99-100, the reader is left in total confusion. Are the authors of Pandas talking about "intelligent design" or an "intelligent agency" or a "personal agent" or a "preexistent intelligence"? Pandas is so confused and circular in its reasoning that it clearly does not meet the test of a good science book; however, it would fit in nicely in a comparative religion class or a class on investigating pseudoscience and the uses of propaganda.
The crux of the issue is that so-called "intelligent design", which has been described as one of the latest evolutions of the ever-evolving creationist movement, is based on supernatural intervention. In effect, "intelligent design" assumes that God was involved at various points in the evolutionary process, but it provides no evidence in support of this belief. Given that the Catholic Church and the mainstream Protestant community have accepted evolution as the way God created the millions of species, one wonders why the creationists still insist upon a literal reading of Genesis. Theologian Langdon Gilkey has stated that creationists come "very close, yes, very close indeed to the first, and worst, Christian heresy!" (emphasis in original) because they try to separate the act of creation from God as if there were two gods, which was the heretical position of the Gnostics (Gilkey 1985). Thus, not only is creationism or "intelligent design" bad science, it is also arguably bad theology!
Professor of philosophy and zoology Michael Ruse has written this about Pandas:
And, let me (for what seems the millionth time in my life) protest at the Creationists appropriating exclusively unto themselves the mantle of religion. The world of life may or may not be designed. But the argument is not that the choice is between an exclusive disjunction of evolution and design. I believe that if God chooses to do things through unbroken law, then that is God's business, not ours. What is our business is the proper use of our God-given powers of sense and reason, to follow fearlessly where the quest for truth leads. Where it does not lead is to the pages of the book Of Pandas and People (Ruse 1989).
"Intelligent design" suffers from a fatal philosophical flaw:
[O]ne might suppose that if organisms are not ideally adapted, if they have characteristics that are not adaptations, they could not have been intelligently designed-or at least the designer couldn't come up with the right materials or the right plan. A designer wouldn't equip organisms with useless appurtenances; yet every species has vestigial structures that may once have been adaptive but are adaptive no longer. Every species also has characteristics that are not now and never were adaptive-characteristics that are the "side effects" of genes that serve some other adaptive function (Futuyma 1995, 128-9).
Presumably the intelligent designer is not so intelligent!
The premise of Pandas is the faulty notion that science should proceed from the supernatural to the natural. Science, by definition, is based on studying the natural world. We do not have Hindu science or Mormon science or Catholic science or Protestant science; we just have science. If the apparently fundamentalist-inspired Pandas is allowed into the classroom, then every religious group can claim with equal justification to have its books included too.
In the 1982 Arkansas court case on teaching creationism (Rev Bill McLean et al. v. Arkansas Board of Education), Judge William R Overton defined science in his ruling against the teaching of creationism (Gilkey 1985; Pennock 1999):
- It is guided by natural law;
- It has to be explanatory by reference to natural law;
- It is testable against the empirical world;
- Its conclusions are tentative, that is, they are not necessarily the final word; and
- It is falsifiable.
"Intelligent design" fails these tests. Furthermore, Overton (and others) found that "intelligent design" promotes a particular sectarian view in violation of the First Amendment.
Pandas co-author Percival Davis has exposed his biblical literalist bias in a book (A Case for Creation) that he wrote with Wayne Frair: "We accept by faith the revealed fact that God created living things. We believe God simultaneously created those crucial substances (nucleic acids, proteins, and so on) that are so intricately interdependent in all of life's processes, and that He created them already functioning in living cells" (quoted in Pennock 1999, 162). The notion that God operated in an evolutionary way (as accepted by the Catholic Church, mainstream Protestant churches, and various American Jewish organizations) seems not to have affected Davis.
The other co-author, Dean Kenyon, was "an erstwhile origin of life researcher who became discouraged about the whole field and subsequently [lent his name in support of YEC [young-earth creationist] activism..." (Pennock 1999, 162). With no scientific support, Pandas tries to be both "young earth" and "old earth" (see page 92). Young-earth creationists believe that the earth along with the entire universe was created 6000 to 10 000 years ago. To date, there is no recognized scientific support in any field of science for such a belief. There have been many years of student complaints about Dean Kenyon's teaching at San Francisco State University, mainly centered on allegations that he is more interested in what amounts to religious proselytizing than in teaching peer-reviewed biology (Scott 1994). From the foregoing, one would suspect that if Pandas were adopted in biology classes, the next step would be to insist that anthropology, geology, physics, chemistry, and astronomy courses be changed to fit with a literal interpretation of the Bible.
Professor Douglas J Futuyma summed up the issue best with his observation:
Suppose creationism had equal time in science classes. What would be taught? If creationists teach that the universe and all its inhabitants were suddenly created a few thousand years ago, and that all of extinction and all of geology were caused by a universal flood, what more can they say? Shall they provide scientific evidence that explains why blue-green algae are in the lowest geological strata and flowering plants in the uppermost? Shall they explain, in terms of modern biology, how a million or more species of animals fit into the ark? Shall they provide evidence from modern physics that explains away the fact that we can perceive light from stars that are billions of light years away, and took billions of years to get here? Shall they provide a testable hypothesis to explain the genetic similarity of apes and humans? Will they describe experiments that elucidate the mechanisms of creation, as geneticists have the mechanisms of evolution? You will seek in vain for answers... (Futuyma 1995, 215-6).Pandas commits the philosophical error of assuming that because our minds see order there must be an intelligent designer. But a number of laboratory experiments (see, for example, Amabilino and Stoddart 1994, Futuyma 1995, and Ingber 1998) have shown that matter can self-organize. Scientists have even observed single-celled amoebas self-organizing into a sort of multicellular creature (Zimmer 1998). Studies in the mathematical field of complexity theory have shown that chaotic systems can exhibit patterns that look like order. Computer studies have shown how evolution can work (see, for example, Dawkins 1986 and chapter 2 of Pennock 1999). In short, Of Pandas and People fails to deal with the very real probability that order is intrinsic in nature and not superimposed.
Finally, by assuming that life originated by "intelligent design", Pandas opens up a number of questions it fails to answer, such as "Who or what is the intelligent designer?" and "Who or what created the intelligent designer?"
Using the arguments in Pandas, one could equally well support the view advanced by the Raëlian Movement "that intelligent aliens landed here millennia ago in spaceships and formed all of life on earth, including human beings, using highly advanced genetic engineering" (Pennock 1999, 234). If one put Pandas in the classroom, in fairness one would also have to put in the Raëlian book The Book That Tells The Truth. As Professor of Philosophy Robert T Pennock has observed, if we allow Pandas, we would also have to allow "textbooks that advocate Claude Vorilhon's Raëlian model, the Swami Prabhupade's cyclical Hindu model, and so on. As they say, this way lies madness" (Pennock 1999, 368).
Pandas tries to bias the reader by the choice of words the authors use to describe the two positions they discuss. Scientists are referred to as "Darwinists" as if to say that all scientists are followers of some religious guru named Darwin. In light of new information, evolutionary science has moved beyond Darwin's original ideas and so scientists working in the field of evolution should properly be referred to as "scientists". Using the verbal tactics of the authors of Pandas, one would have to refer to advocates of "intelligent design" as "Morrisites" (in acknowledgment of the biblical literalist Henry M Morris who was instrumental in founding the modern fundamentalist belief known as creationism or "intelligent design").
Perhaps Kevin Padian, Professor of Integrative Biology and Curator in the Museum of Paleontology at the University of California, Berkeley, said it best:
Of Pandas and People is a tract on hard-shell fundamentalist creationism in disguise. This underlying theme never speaks its name in this tract, but it is there nonetheless. It is hard to say what is worst in this book: the misconceptions of its sub-text, the intolerance for honest science, or the incompetence with which science is presented. In any case, teachers should be warned against using this book (Padian 1989).
The complete list of references is contained in the longer "Review of the book Of Pandas and People: The Central Question of Biological Origins (second edition)" by Gary L Bennett, which will be available soon on The Textbook Letter web site. Other reviews of Pandas from The Textbook League are available on line at
References
Amabilino D, Stoddart F. Molecules that build themselves. New Scientist 1994 Feb 19: 25-9.Darwin CR. The Origin of Species By Means of Natural Selection or The Preservation of Favored Races in the Struggle for Life. NY: Avenue Books, 1979 [originally published in 1859].
Dawkins R. The Blind Watchmaker. NY: WW Norton & Company, 1986.
Futuyma DJ. Science on Trial: The Case for Evolution. Sunderland (MA): Sinauer Associates, Inc, 1995.
Gilkey L. Creationism on Trial: Evolution and God at Little Rock. Minneapolis (MN): Winston Press, Inc, 1985.
Ingber DE. The architecture of life. Scientific American 1998 Jan; 278 (1): 48-57.
NAS (1999) Science and Creationism: A View from the National Academy of Sciences, 2nd edition. Washington (DC): National Academy Press, 1999.
Padian K. Gross misrepresentation. Bookwatch Reviews 1989; 2 (11): xxx-xxx.
Padian K, Chiappe LM. The origin of birds and their flight. Scientific American 1998 Feb; 278 (2): 38-47.
Pennock RT. Tower of Babel: The Evidence against the New Creationism. The MIT Press, Cambridge (MA), 1999.
Pennisi E, Roush W. Developing a new view of evolution. Science 1997 Jul 4; 277 (5322): 34-7.
Ruse M. They're here! Bookwatch Reviews 1989; 2 (11): xxx-xxx.
Scott EC. Dean Kenyon and "intelligent design theory" at San Francisco State U. NCSE Reports 1993/1994; 13 (4)/14 (1): 1, 5, 13.
Zimmer C. The slime alternative. Discover 1998 Sep; 19 (9): 86-93.
An Interview with Edward J Larson
Karl W Giberson is Professor of Physics and Director of the General Science Program, and Donald A Yerxa is Professor of History and Director of the Pre-Law Program, both at Eastern Nazarene College.
[Edward J Larson won a Pulitzer Prize in 1998 for his book Summer for the Gods - a re-examination of the events surrounding the Scopes trial and of the people involved in it. During a visit to Eastern Nazarene College on October 21, 1999, Larson spoke with Karl Giberson and Donald Yerxa. We have excerpted portions of that interview to present to readers of RNCSE. Larson did not receive, review, or revise the published text of the interview.]
Giberson: Can you give our readers some background about yourself, particularly mentioning your formative religious experiences?
Larson: I was raised in rural central-southern Ohio. My parents were members of the Congregational Church, which was probably the most liberal church in my hometown. We were not very active at all, though we did go to church occasionally. Evolution was just assumed in my high school. I took a lot of science classes and was very interested in the sciences. I believe that we used the BSCS texts, but we might have used a revised edition of Truman Moon's Modern Biology II.
Yerxa: Have there been any instances in your life when you struggled over issues related to science and religion?
Larson: Not really. I mostly come from a science background, and I have not noticed any particular conflict in my own mind. I have not studied it closely, but to the extent that I have, I think that Stephen Jay Gould's "non-overlapping magisteria" is a nice way to articulate it.
Yerxa: What prompted you - a recipient of multiple high school science awards - to pursue both a doctorate in history at Wisconsin and a law degree and Harvard?
Larson: In high school I took a lot of science and math, but I always loved history. As a kid I just thoroughly enjoyed reading history, and, even though I did not get much history instruction in high school, I taught myself history and went ahead and took the Advanced Placement exams in both European and American history at the end of my high school years. When I was an undergraduate at Williams College, I learned that there was a field called the history of science. Williams had a historian of science named Donald Beaver, and I took his class and suddenly it brought together two interests, my persistent love of nature and the understanding of how nature operates - which is why I like science - and my love of history. So suddenly I could study the history of science.
Yerxa: What was the topic of your doctoral dissertation?
Larson: Initially, my major professor Dave Lindberg encouraged me to cross disciplines and get a law degree. The law courses served as my minor for the PhD at Wisconsin, but beyond that, law enriched my scholarship. I thought that I was going to write in the area of eugenics, but the untimely death of Bill Coleman, a historian of biology at Wisconsin, presented me with the opportunity to have Ronald Numbers as my major professor and I ended up working with him. He pushed me in a direction that I would not otherwise have gone in, but have ever after found interesting. Since Numbers was working on the history of the creation/evolution controversy, and he knew I had this legal background, he encouraged me to work on the legal history of the creation/evolution controversy, so that is primarily what my dissertation dealt with. It was a little broader than that in the sense that it deals with how courts deal with legal questions, but it primarily deals with the creation/evolution controversy throughout history. The dissertation became my first book, Trial and Error.
Yerxa: How did you decide to write a book on the Scopes trial? Did you feel that there was some sort of misunderstanding of the trial in the historical literature?
Larson: It was a bit serendipitous how I ended up with the topic. Certainly in the background there was the fact that I knew the trial was not very well understood. During my dissertation research, I had looked a little bit into the Scopes trial, and in Trial and Error there is a very small passage, a couple of pages, on it. But in researching just that little snippet on the Scopes trial, I had discovered that there was a rich body of archival literature on the trial that no historian had ever used. The last serious book on the Scopes trial was from the 1950s, and that relied almost exclusively on a reading of newspapers in the period. And I knew the ACLU archives were available and open. Of course Bryan's archives had been open, but they had not been used very much. Clarence Darrow's papers were available, but I also knew that there were some additional sources of information. In particular, Judge Hicks, who had been one of the prosecutors, had saved all the correspondence among members of the prosecution team, and he had subsequently put it into the University of Tennessee archives. Up to that point those documents simply had not been used by any other historian.
So I now knew that there was quite a bit of archival material. Moreover, the main treatments of the trial were written in the shadow of McCarthyism and the threat to popular and individual liberty based on mob action and emotionalism. Inherit the Wind and Six Days or Forever?: Tennessee v John Thomas Scopes (Ray Ginger's scholarly book of the same period) were consciously and explicitly written with McCarthy-era witch hunts of communists and socialists in mind and were looking back at the Scopes trial as an earlier episode of all this. Then in the 1990s we have a new perspective on fundamentalism and anti-evolutionism. They are still alive in the US; they were not slain in Dayton. And that was always part of the premise of Inherit the Wind and Six Days or Forever? - that exposing Bryan killed these movements. But it did not. So now in a sense we have better historical perspective for looking at those documents. And that is the foundation for doing constructive history - new archival material and a new perspective that previous historians haven't been able to bring to bear on the topic.
The actual precipitant that made Summer for the Gods happen was much more pedestrian, however. During the middle of the OJ Simpson trial, one of my colleagues suggested, out of the blue, that I write a book on the Scopes trial. Not knowing any of what I knew about the archival material or the added perspective, he knew that I wrote legal history and was trained in the history of science. While he was watching the OJ Simpson trial, he concluded that I was one of the few people he knew with expertise in both of those fields. He kept hearing during the Simpson trial coverage about the other trials of the century, and in particular about the Scopes trial. Here was one event in history that seemed to involve law and science together. And when he said that, it just clicked immediately. It made sense, and I immediately thought that it was a great topic.
Yerxa: What would you like the reader to take away from Summer for the Gods?
Larson: I usually do not try to put myself in the reader's mind. I am trying just to tell a story that I enjoy telling, and whatever readers draw from it is their business. I appreciate the richness of a historical event and how nothing important in history is ever simple. There are many currents and crosscurrents and factors involved. I don't see these individual characters as sort of simple, 2-dimensional figures, but 3-dimensional figures with a richness and dignity. And I would hope that people would draw out the richness of the historical event and the many factors that play into it.
I did not go into the Scopes trial doing the research for Summer for the Gods with a particularly high opinion of either Clarence Darrow or William Jennings Bryan. What has impressed me throughout my life is that whenever you treat people honestly at their own level, when you get to understand them more, you get to appreciate them more. I read much of what Bryan and Darrow wrote and tried really to immerse myself in them, so I could understand them as people. And I ended my research with a much higher opinion of those 2 great Americans than when I started. I am not asking that my readers also end with a higher opinion of Bryan and Darrow. But since I came out that way, I would hope that they would as well. I would hope that they would treat them on their own terms and grow to respect what Clarence Darrow and William Jennings Bryan were doing. And when we understand what they were doing, and we understand what was at stake, I think that it makes the situation today more understandable.
Yerxa: Has winning the Pulitzer Prize changed your life significantly?
Larson: With the prize come more distractions - invitations to speak, invitations to write on topics that don't have any relevance to what I am doing. It is far more difficult to control my own schedule. But there are also wonderful opportunities that come, for example, chances to go out and meet Jerome Lawrence, the co-writer of Inherit the Wind, and opportunities to speak at interesting occasions and to meet other people and to try to help students and help the cause of history. I am in this respect first and foremost a historian, and I am interested in the discipline of history. Now people ask me about historical questions and about becoming a historian and the value of doing history, and I can be an evangelist for history and the role of history. I enjoy that. So it is a mixed blessing, and the challenge is to maximize the good out of it while not being sucked into the bad and not losing my own control over what I think my career should be.
Yerxa: What are your current projects?
Larson: I am working on a book on the history of scientific research on the Galapagos Islands, which has the same advantage as a book on the Scopes trial in the sense that I think that it is an absolutely fabulous topic. Everybody has heard of the Galapagos Islands just as everybody has heard of the Scopes trial, but nobody has ever written a history of the scientific research on the Galapagos Islands. There is a wonderful recent book on the Grants' work called The Beak of the Finch, but it is just about the work of Peter and Rosemary Grant. It is not a history of scientific research. It certainly does not deal with the past. I hope that I will be able, as with the Scopes book, to reach an audience beyond historians of science but that will include historians of science.
Yerxa: You have been involved in some sociology of science lately with your colleague Larry Witham. You have revisited James Leuba's 1914 and 1933 surveys of scientists to get a sense of how both rank and file scientists as well as the scientific elite view belief in God. What are your findings in a nutshell?
Larson: Well, it is a curious survey to have to repeat Leuba's question, because he had a very particular definition of God that may exclude many people. He was asking about belief in sort of a traditional theistic God that would resonate with traditional Jews, Muslims, or Christians. Indeed you might want to call them orthodox Jews, Muslims, and Christians. There was a lot of talk back at the turn of the century that positivism and science were routing belief in God, and so he did a survey of both the rank and file scientists and the elite scientists - surveys that we were able to reproduce. Leuba found about 40% belief in this sort of God among the rank and file and much lower levels of belief among elites, and that is exactly what we found.
He received many objections that "this God does not capture my God". He would get people who would write back and say that "I do not believe in any God, but I am deeply religious." He would also get people who said, "Well, I believe in a God that is immanent in nature, and I do not believe that this is a God that you can talk to or who can answer questions. Your question does not capture what I am talking about." We received the same sort of reactions, and I sympathize with them because I think they are right, but the only way you can do a longitudinal survey is to ask the same questions. As a historian, I was interested in Leuba's survey because it had been so important in the Scopes trial and Bryan's anti-evolution crusade. He had made it a centerpiece. His prime evidence against evolution was this disbelief among scientists, so I was interested in the precise question. And we found that it was basically constant over time.
Yerxa: What is it about the US that makes it so receptive to anti-Darwinian notions?
Larson: Partly because we're democratic. We have a democratic, anti-elitist tradition. There is a rooting for the underdog, and there is a suspicion of elites in the US that just is not as present in, say, France, Germany, or in Scandinavia where they have a traditional hierarchical society and where the people are more willing to defer automatically to elites in any particular area of expertise. We have more of a tradition in the US where citizens get to make up their own minds on everything, everyone is an expert and everyone is an authority, and no one should automatically follow other peoples' decisions - people should think for themselves. So that makes the US open to questioning the pronouncements of the scientific elite and to want to think through these questions for themselves and come to their own conclusions.
Yerxa: How do you explain the Phillip Johnson phenomenon and the emergence of "intelligent design" in the origins discussion?
Larson: I think that Johnson is a very articulate speaker and advocate. He is obviously a skilled lawyer, and he's raising popular concerns and questions in the sense that if you believe in a traditional Christian God - and it doesn't have to be a fundamentalist God - do you not believe that God could interfere in nature? And if you believe that God could interfere in nature, do you not believe that God did interfere in nature? And if God did interfere in nature, then how can you understand natural phenomena without at least considering God as the author of those? So his argument against philosophical naturalism in science, as he likes to put it, has an instinctive appeal to many Americans who believe in that sort of God.
Yerxa: Does this line of reasoning appeal to you?
Larson: Johnson has got to bring scientists into the debate, and there has to be a controversy within the scientific community. There have to be scientists who start doing "intelligent design" as science. And I have not yet seen that happen. But in the end, if he is going to change science, it is going to have to be through scientists and not through the general public.
Yerxa: You used the phrase "'intelligent design' as science". What would that look like?
Larson: That is for the scientists to decide. I can say that I am neither a scientist nor a philosopher. I am sort of a philosopher of science, and I take a mundane definition of science. I know you can come up with wonderful definitions about what science is: it is a falsifiable enterprise and a set of shifting paradigms, and so on, but I take the journeyman's view that science is what scientists do and that scientists define their profession just as other people define their profession. So I think the key test for "intelligent design" will come if and when scientists start doing "intelligent design" research. And only if and when they start doing it will we know what an "intelligent design" science looks like. And, as a historian, I am not a very good person to answer that question.
Giberson: Part of the reason for the success of Phillip Johnson is the perception that there are people like Richard Dawkins out there who are missionaries for naturalism with an agenda that goes far beyond just trying to help people understand evolution. Can you comment on the way people like Dawkins, Peter Atkins, even EO Wilson, are their own worst enemies in that they make science unpopular in American culture by attaching it to an aggressively anti-religious stance.
Larson: I do not think that they are their own worst enemies. I think that they are reaching a broad and powerful audience. Their works are inspirational to many people. And I think for all the people they turn off, they inspire a whole other group. Wilson's teaching at Harvard is inspirational; his writings are inspirational. Certainly he makes the feminists furious, but he also inspires a lot of critical thought. Dawkins makes many religious people furious, but he inspires them to think harder and debate the issue harder. I think that he wants that. I think that he wants to raise those questions, and I have met many students who have been profoundly inspired to go into science and make a career in science because of books like Dawkins's The Blind Watchmaker. So these writers are doing missionary work for science that is inspirational because of their tremendous skill as writers. And so I think that if you had to weigh the pluses and minuses against each other - and I do not think that I could do the final reckoning - that they would be quite pleased with what they have accomplished.
Giberson: If you look at the premier popularizers of science, the ones who are capable of inspiring young people to go into science - people like Dawkins, Carl Sagan, Stephen Jay Gould, EO Wilson, and Stephen Weinberg - none of these people is religious in any conventional sense. Do the people who read them get a distorted perception of what the scientific community is like because these public spokespersons happen to have atheistic worldviews? And does it then become generalized in the popular mind that science itself is an atheistic enterprise, so that what Phillip Johnson says about the naturalism of science rings true?
Larson: When you put it that way, I do think that Phillip Johnson, by his own terms, was enraged and energized by reading The Blind Watchmaker. And I think that he uses them as examples of atheism in science. Yet even Johnson is probably raising up people to go into science, at first to refute them, but later they get involved with science and end up becoming good scientists participating in the scientific enterprise. I have great respect for the people you named. Every one of those people that I know personally, I have tremendous respect for as scholars and as honorable people. And I think that they welcome this debate and discussion, and they would rather have these issues out in the open and discussed and debated in the US so people can think about these issues.
But certainly I do think that they are lightning rods, and they raise controversy. As a result of the controversy they raise, there is a perception in the US that there is a warfare between science and religion. One of the reasons that our initial survey of science and religious beliefs got so much attention was that it found that 40% of scientists in the US believe in something like the traditional God of Judaism, Islam, and Christianity. And that was newsworthy. It is not newsworthy when a dog bites a person; it is newsworthy when a person bites a dog, and this was a person-bites-dog story. It was just the reverse, by the way, when Leuba first published his survey. It was also front-page news, but then it was only 40% believe in God. Now it is newsworthy for the opposite reason; 40% is a higher percentage than people today would have thought. Something must have given the impression at least to the US news media that it is surprising that 40% of US scientists believe in God. And that partly comes out with the public voice of science.
Giberson: In thinking about the creation/evolution controversy, what I find attractive about scientific creationism is the simplicity of its model. It is a tidy system based upon the priority of the Bible. What is attractive about Dawkins and that group is the same sort of simplicity. It is metaphysically consistent; it all fits together. In the middle are the people trying to carve out the theistic evolution models that somehow bring these 2 together, and they end up being ambiguous and fraught with difficulty and so on. What do you think of the attempts to create theistic evolutionary models?
Larson: It is nice to have simplistic answers to your views on origins or your worldview, but when people are thinking about their view of origins, they think about it with more richness than they are often given credit for. If they focus on this, they think about the options of, well, could God create the evolutionary process? Could that be the means of creation, or is it a purely naturalistic process? Or does God work in successive creations as Cuvier once thought? Or is the human soul separate as the Pope would say: the body evolved with the human soul separate? And they can come up with different reconciliations of those different views. I think that you do an injustice to the issue to think that people just have to put it simplistically into one category. To the extent that they focus on the issue, people can come up with some personal reconciliation of the 2 and then go ahead with their lives. I think that it does them an injustice to think that they are going to read an account by a scientist or by a religious person, and just say, that is it.
[This feature is adapted from a longer article appearing in Books and Culture: A Christian Review 1999 Nov/Dec; 5 [6]: 30; reprinted and adapted with permission.]
[Edward J Larson won a Pulitzer Prize in 1998 for his book Summer for the Gods - a re-examination of the events surrounding the Scopes trial and of the people involved in it. During a visit to Eastern Nazarene College on October 21, 1999, Larson spoke with Karl Giberson and Donald Yerxa. We have excerpted portions of that interview to present to readers of RNCSE. Larson did not receive, review, or revise the published text of the interview.]
Giberson: Can you give our readers some background about yourself, particularly mentioning your formative religious experiences?
Larson: I was raised in rural central-southern Ohio. My parents were members of the Congregational Church, which was probably the most liberal church in my hometown. We were not very active at all, though we did go to church occasionally. Evolution was just assumed in my high school. I took a lot of science classes and was very interested in the sciences. I believe that we used the BSCS texts, but we might have used a revised edition of Truman Moon's Modern Biology II.
Yerxa: Have there been any instances in your life when you struggled over issues related to science and religion?
Larson: Not really. I mostly come from a science background, and I have not noticed any particular conflict in my own mind. I have not studied it closely, but to the extent that I have, I think that Stephen Jay Gould's "non-overlapping magisteria" is a nice way to articulate it.
Yerxa: What prompted you - a recipient of multiple high school science awards - to pursue both a doctorate in history at Wisconsin and a law degree and Harvard?
Larson: In high school I took a lot of science and math, but I always loved history. As a kid I just thoroughly enjoyed reading history, and, even though I did not get much history instruction in high school, I taught myself history and went ahead and took the Advanced Placement exams in both European and American history at the end of my high school years. When I was an undergraduate at Williams College, I learned that there was a field called the history of science. Williams had a historian of science named Donald Beaver, and I took his class and suddenly it brought together two interests, my persistent love of nature and the understanding of how nature operates - which is why I like science - and my love of history. So suddenly I could study the history of science.
Yerxa: What was the topic of your doctoral dissertation?
Larson: Initially, my major professor Dave Lindberg encouraged me to cross disciplines and get a law degree. The law courses served as my minor for the PhD at Wisconsin, but beyond that, law enriched my scholarship. I thought that I was going to write in the area of eugenics, but the untimely death of Bill Coleman, a historian of biology at Wisconsin, presented me with the opportunity to have Ronald Numbers as my major professor and I ended up working with him. He pushed me in a direction that I would not otherwise have gone in, but have ever after found interesting. Since Numbers was working on the history of the creation/evolution controversy, and he knew I had this legal background, he encouraged me to work on the legal history of the creation/evolution controversy, so that is primarily what my dissertation dealt with. It was a little broader than that in the sense that it deals with how courts deal with legal questions, but it primarily deals with the creation/evolution controversy throughout history. The dissertation became my first book, Trial and Error.
Yerxa: How did you decide to write a book on the Scopes trial? Did you feel that there was some sort of misunderstanding of the trial in the historical literature?
Larson: It was a bit serendipitous how I ended up with the topic. Certainly in the background there was the fact that I knew the trial was not very well understood. During my dissertation research, I had looked a little bit into the Scopes trial, and in Trial and Error there is a very small passage, a couple of pages, on it. But in researching just that little snippet on the Scopes trial, I had discovered that there was a rich body of archival literature on the trial that no historian had ever used. The last serious book on the Scopes trial was from the 1950s, and that relied almost exclusively on a reading of newspapers in the period. And I knew the ACLU archives were available and open. Of course Bryan's archives had been open, but they had not been used very much. Clarence Darrow's papers were available, but I also knew that there were some additional sources of information. In particular, Judge Hicks, who had been one of the prosecutors, had saved all the correspondence among members of the prosecution team, and he had subsequently put it into the University of Tennessee archives. Up to that point those documents simply had not been used by any other historian.
So I now knew that there was quite a bit of archival material. Moreover, the main treatments of the trial were written in the shadow of McCarthyism and the threat to popular and individual liberty based on mob action and emotionalism. Inherit the Wind and Six Days or Forever?: Tennessee v John Thomas Scopes (Ray Ginger's scholarly book of the same period) were consciously and explicitly written with McCarthy-era witch hunts of communists and socialists in mind and were looking back at the Scopes trial as an earlier episode of all this. Then in the 1990s we have a new perspective on fundamentalism and anti-evolutionism. They are still alive in the US; they were not slain in Dayton. And that was always part of the premise of Inherit the Wind and Six Days or Forever? - that exposing Bryan killed these movements. But it did not. So now in a sense we have better historical perspective for looking at those documents. And that is the foundation for doing constructive history - new archival material and a new perspective that previous historians haven't been able to bring to bear on the topic.
The actual precipitant that made Summer for the Gods happen was much more pedestrian, however. During the middle of the OJ Simpson trial, one of my colleagues suggested, out of the blue, that I write a book on the Scopes trial. Not knowing any of what I knew about the archival material or the added perspective, he knew that I wrote legal history and was trained in the history of science. While he was watching the OJ Simpson trial, he concluded that I was one of the few people he knew with expertise in both of those fields. He kept hearing during the Simpson trial coverage about the other trials of the century, and in particular about the Scopes trial. Here was one event in history that seemed to involve law and science together. And when he said that, it just clicked immediately. It made sense, and I immediately thought that it was a great topic.
Yerxa: What would you like the reader to take away from Summer for the Gods?
Larson: I usually do not try to put myself in the reader's mind. I am trying just to tell a story that I enjoy telling, and whatever readers draw from it is their business. I appreciate the richness of a historical event and how nothing important in history is ever simple. There are many currents and crosscurrents and factors involved. I don't see these individual characters as sort of simple, 2-dimensional figures, but 3-dimensional figures with a richness and dignity. And I would hope that people would draw out the richness of the historical event and the many factors that play into it.
I did not go into the Scopes trial doing the research for Summer for the Gods with a particularly high opinion of either Clarence Darrow or William Jennings Bryan. What has impressed me throughout my life is that whenever you treat people honestly at their own level, when you get to understand them more, you get to appreciate them more. I read much of what Bryan and Darrow wrote and tried really to immerse myself in them, so I could understand them as people. And I ended my research with a much higher opinion of those 2 great Americans than when I started. I am not asking that my readers also end with a higher opinion of Bryan and Darrow. But since I came out that way, I would hope that they would as well. I would hope that they would treat them on their own terms and grow to respect what Clarence Darrow and William Jennings Bryan were doing. And when we understand what they were doing, and we understand what was at stake, I think that it makes the situation today more understandable.
Yerxa: Has winning the Pulitzer Prize changed your life significantly?
Larson: With the prize come more distractions - invitations to speak, invitations to write on topics that don't have any relevance to what I am doing. It is far more difficult to control my own schedule. But there are also wonderful opportunities that come, for example, chances to go out and meet Jerome Lawrence, the co-writer of Inherit the Wind, and opportunities to speak at interesting occasions and to meet other people and to try to help students and help the cause of history. I am in this respect first and foremost a historian, and I am interested in the discipline of history. Now people ask me about historical questions and about becoming a historian and the value of doing history, and I can be an evangelist for history and the role of history. I enjoy that. So it is a mixed blessing, and the challenge is to maximize the good out of it while not being sucked into the bad and not losing my own control over what I think my career should be.
Yerxa: What are your current projects?
Larson: I am working on a book on the history of scientific research on the Galapagos Islands, which has the same advantage as a book on the Scopes trial in the sense that I think that it is an absolutely fabulous topic. Everybody has heard of the Galapagos Islands just as everybody has heard of the Scopes trial, but nobody has ever written a history of the scientific research on the Galapagos Islands. There is a wonderful recent book on the Grants' work called The Beak of the Finch, but it is just about the work of Peter and Rosemary Grant. It is not a history of scientific research. It certainly does not deal with the past. I hope that I will be able, as with the Scopes book, to reach an audience beyond historians of science but that will include historians of science.
Yerxa: You have been involved in some sociology of science lately with your colleague Larry Witham. You have revisited James Leuba's 1914 and 1933 surveys of scientists to get a sense of how both rank and file scientists as well as the scientific elite view belief in God. What are your findings in a nutshell?
Larson: Well, it is a curious survey to have to repeat Leuba's question, because he had a very particular definition of God that may exclude many people. He was asking about belief in sort of a traditional theistic God that would resonate with traditional Jews, Muslims, or Christians. Indeed you might want to call them orthodox Jews, Muslims, and Christians. There was a lot of talk back at the turn of the century that positivism and science were routing belief in God, and so he did a survey of both the rank and file scientists and the elite scientists - surveys that we were able to reproduce. Leuba found about 40% belief in this sort of God among the rank and file and much lower levels of belief among elites, and that is exactly what we found.
He received many objections that "this God does not capture my God". He would get people who would write back and say that "I do not believe in any God, but I am deeply religious." He would also get people who said, "Well, I believe in a God that is immanent in nature, and I do not believe that this is a God that you can talk to or who can answer questions. Your question does not capture what I am talking about." We received the same sort of reactions, and I sympathize with them because I think they are right, but the only way you can do a longitudinal survey is to ask the same questions. As a historian, I was interested in Leuba's survey because it had been so important in the Scopes trial and Bryan's anti-evolution crusade. He had made it a centerpiece. His prime evidence against evolution was this disbelief among scientists, so I was interested in the precise question. And we found that it was basically constant over time.
Yerxa: What is it about the US that makes it so receptive to anti-Darwinian notions?
Larson: Partly because we're democratic. We have a democratic, anti-elitist tradition. There is a rooting for the underdog, and there is a suspicion of elites in the US that just is not as present in, say, France, Germany, or in Scandinavia where they have a traditional hierarchical society and where the people are more willing to defer automatically to elites in any particular area of expertise. We have more of a tradition in the US where citizens get to make up their own minds on everything, everyone is an expert and everyone is an authority, and no one should automatically follow other peoples' decisions - people should think for themselves. So that makes the US open to questioning the pronouncements of the scientific elite and to want to think through these questions for themselves and come to their own conclusions.
Yerxa: How do you explain the Phillip Johnson phenomenon and the emergence of "intelligent design" in the origins discussion?
Larson: I think that Johnson is a very articulate speaker and advocate. He is obviously a skilled lawyer, and he's raising popular concerns and questions in the sense that if you believe in a traditional Christian God - and it doesn't have to be a fundamentalist God - do you not believe that God could interfere in nature? And if you believe that God could interfere in nature, do you not believe that God did interfere in nature? And if God did interfere in nature, then how can you understand natural phenomena without at least considering God as the author of those? So his argument against philosophical naturalism in science, as he likes to put it, has an instinctive appeal to many Americans who believe in that sort of God.
Yerxa: Does this line of reasoning appeal to you?
Larson: Johnson has got to bring scientists into the debate, and there has to be a controversy within the scientific community. There have to be scientists who start doing "intelligent design" as science. And I have not yet seen that happen. But in the end, if he is going to change science, it is going to have to be through scientists and not through the general public.
Yerxa: You used the phrase "'intelligent design' as science". What would that look like?
Larson: That is for the scientists to decide. I can say that I am neither a scientist nor a philosopher. I am sort of a philosopher of science, and I take a mundane definition of science. I know you can come up with wonderful definitions about what science is: it is a falsifiable enterprise and a set of shifting paradigms, and so on, but I take the journeyman's view that science is what scientists do and that scientists define their profession just as other people define their profession. So I think the key test for "intelligent design" will come if and when scientists start doing "intelligent design" research. And only if and when they start doing it will we know what an "intelligent design" science looks like. And, as a historian, I am not a very good person to answer that question.
Giberson: Part of the reason for the success of Phillip Johnson is the perception that there are people like Richard Dawkins out there who are missionaries for naturalism with an agenda that goes far beyond just trying to help people understand evolution. Can you comment on the way people like Dawkins, Peter Atkins, even EO Wilson, are their own worst enemies in that they make science unpopular in American culture by attaching it to an aggressively anti-religious stance.
Larson: I do not think that they are their own worst enemies. I think that they are reaching a broad and powerful audience. Their works are inspirational to many people. And I think for all the people they turn off, they inspire a whole other group. Wilson's teaching at Harvard is inspirational; his writings are inspirational. Certainly he makes the feminists furious, but he also inspires a lot of critical thought. Dawkins makes many religious people furious, but he inspires them to think harder and debate the issue harder. I think that he wants that. I think that he wants to raise those questions, and I have met many students who have been profoundly inspired to go into science and make a career in science because of books like Dawkins's The Blind Watchmaker. So these writers are doing missionary work for science that is inspirational because of their tremendous skill as writers. And so I think that if you had to weigh the pluses and minuses against each other - and I do not think that I could do the final reckoning - that they would be quite pleased with what they have accomplished.
Giberson: If you look at the premier popularizers of science, the ones who are capable of inspiring young people to go into science - people like Dawkins, Carl Sagan, Stephen Jay Gould, EO Wilson, and Stephen Weinberg - none of these people is religious in any conventional sense. Do the people who read them get a distorted perception of what the scientific community is like because these public spokespersons happen to have atheistic worldviews? And does it then become generalized in the popular mind that science itself is an atheistic enterprise, so that what Phillip Johnson says about the naturalism of science rings true?
Larson: When you put it that way, I do think that Phillip Johnson, by his own terms, was enraged and energized by reading The Blind Watchmaker. And I think that he uses them as examples of atheism in science. Yet even Johnson is probably raising up people to go into science, at first to refute them, but later they get involved with science and end up becoming good scientists participating in the scientific enterprise. I have great respect for the people you named. Every one of those people that I know personally, I have tremendous respect for as scholars and as honorable people. And I think that they welcome this debate and discussion, and they would rather have these issues out in the open and discussed and debated in the US so people can think about these issues.
But certainly I do think that they are lightning rods, and they raise controversy. As a result of the controversy they raise, there is a perception in the US that there is a warfare between science and religion. One of the reasons that our initial survey of science and religious beliefs got so much attention was that it found that 40% of scientists in the US believe in something like the traditional God of Judaism, Islam, and Christianity. And that was newsworthy. It is not newsworthy when a dog bites a person; it is newsworthy when a person bites a dog, and this was a person-bites-dog story. It was just the reverse, by the way, when Leuba first published his survey. It was also front-page news, but then it was only 40% believe in God. Now it is newsworthy for the opposite reason; 40% is a higher percentage than people today would have thought. Something must have given the impression at least to the US news media that it is surprising that 40% of US scientists believe in God. And that partly comes out with the public voice of science.
Giberson: In thinking about the creation/evolution controversy, what I find attractive about scientific creationism is the simplicity of its model. It is a tidy system based upon the priority of the Bible. What is attractive about Dawkins and that group is the same sort of simplicity. It is metaphysically consistent; it all fits together. In the middle are the people trying to carve out the theistic evolution models that somehow bring these 2 together, and they end up being ambiguous and fraught with difficulty and so on. What do you think of the attempts to create theistic evolutionary models?
Larson: It is nice to have simplistic answers to your views on origins or your worldview, but when people are thinking about their view of origins, they think about it with more richness than they are often given credit for. If they focus on this, they think about the options of, well, could God create the evolutionary process? Could that be the means of creation, or is it a purely naturalistic process? Or does God work in successive creations as Cuvier once thought? Or is the human soul separate as the Pope would say: the body evolved with the human soul separate? And they can come up with different reconciliations of those different views. I think that you do an injustice to the issue to think that people just have to put it simplistically into one category. To the extent that they focus on the issue, people can come up with some personal reconciliation of the 2 and then go ahead with their lives. I think that it does them an injustice to think that they are going to read an account by a scientist or by a religious person, and just say, that is it.
[This feature is adapted from a longer article appearing in Books and Culture: A Christian Review 1999 Nov/Dec; 5 [6]: 30; reprinted and adapted with permission.]
Anti-Evolutionists Open a New Front
May 10, 2000, was just another day on Capitol Hill. With Congress in session, a dozen or so briefings took place as interest groups were eager to bring their issues before congressional staff. As such, there was nothing particularly remarkable about the briefing and reception by the Seattle-based Discovery Institute on this day. Nor was it surprising that the briefing was part of a broader strategy by the Institute to "cultivate and convince" opinion leaders and policy-makers, including congressional staff. What readers might find remarkable about this briefing was its topic: Scientific Evidence for Intelligent Design and its Implications for Public Policy and Education. It may be that this otherwise normal day was an early move by "Intelligent Design" creationists (IDCs) on their newest front in the struggle against evolution: the US Congress.
Last summer's events in Kansas rekindled the creation/evolution debate around the nation. The Associate Press rated it the top story of 1999. Since then, efforts to discredit evolution have intensified with conflicts raging in county school boards and state capitals. For much of the last 2 decades, the issue has been quintessentially local. But the May 10 briefing could represent a return to a national stage.
Those who attended the briefing were treated to a 3-hour primer on ID creationism from some of the movement's best-known advocates, including Whitworth College philosophy professor Stephen Meyer, Lehigh University biology professor Michael Behe, and University of California law professor Phillip Johnson. All are fellows of the Discovery Institute's Center for the Renewal of Science and Culture (CRSC). Joining them was another CRSC fellow, Nancy Pearcey - the former executive editor of Breakpoint, a conservative talk radio show hosted by born-again Watergate figure Rev Charles Colson, with whom Pearcey writes a regular column.
They did not thump Bibles. They did not try to convince the audience that dinosaurs are the "behemoth" of the Book of Job nor did they seek to explain that the Grand Canyon was formed during the Noachian flood. The IDCs voiced their acceptance of the depth of geologic time, modern genetics, even certain aspects of evolution itself. In fact, IDCs not only accept the advances of science, they argue that those advances have revealed a universe of physical and biological systems so complex that they could not possibly have come from evolutionary processes. Indeed, one theme was how "shocked" scientists have been by their discoveries of the awesome complexity of living systems. Shocked and disheartened, because their outmoded theories such as Darwinian evolution - adequate perhaps for the limited knowledge of the 19th century - cannot handle that complexity. This approach cleverly places ID theory at the cutting edge of scientific discovery while relegating Darwin to the dustbin of history.
Intelligent design, they said, is one side of a debate between 2 competing, empirically derived scientific theories - a debate, they claimed, that does not include religion. In their view, they are engaged in an open-minded investigation to follow the empirical evidence about life on earth wherever it leads. They contrast such openness with a rigid scientific orthodoxy that forcibly constrains explanations to purely natural phenomena, disallowing explanations that involve a higher intelligence. However, the tone of the Congressional briefing does not resonate with articles published by ID's "leading lights" in the nonscientific literature. For example, Pearcey wrote in the May 22 issue of Christianity Today: "Clearly, while [intelligent design theory] does not require any theological presuppositions, it has theological implications: It is resolutely opposed to the atheistic, purposeless, chance view of evolution taught in the power centers of science."
The speakers also tarred evolutionary theory with the controversial findings of social scientists who apply Darwinism to human interactions. Pearcey shocked the audience with a recent book that asserted rape was a natural male impulse driven by the need to confer evolutionary advantage. She also blamed Darwinism for the excesses of popular culture, quoting lyrics from a current hit song: "You and me, baby, ain't nothin' but mammals, so let's do it like they do on the Discovery Channel."
Ironically, the IDCs accept the achievements of science and indeed place their theory at the pinnacle of modern knowledge, but also demonize both the scientists who made those advances and the naturalistic method by which the advances were achieved. At the briefing Johnson replayed the portrayal of scientists from his popular books as an elite priesthood jealously guarding the power and prestige garnered from the ascendancy of their Darwin-inspired creation myth, having deposed the church's priests. There is a disconnect between the pains they take to portray the debate between ID and evolution as purely scientific and this separate line of argument portraying Darwinism as a religion.
Why is this briefing so important to those interested in quality science education? The Discovery Institute chose to hold its briefing at the same time that both the House and Senate were actively considering legislation to overhaul federal K-12 education programs. Scientific societies and other interested groups faced serious challenges as they tried to retain provisions in new federal legislation which supports and strengthens science and math education. If anti-evolutionists move into the Congressional arena and gain support from leading members of Congress, good science will face an even tougher challenge. Their efforts threaten to erode science education at the very moment when our technology-based society needs it more than ever.
For a summary of the May 10, 2000, Congressional briefing, visit www.agiweb.org/gap/legis106/id_update.html.
[Adapted with permission from David Applegate's column in Geotimes 2000 Jul; 45 (7): 12, 58.] David Applegate directs the American Geological Institute's Government Affairs Program and is editor of Geotimes.
Last summer's events in Kansas rekindled the creation/evolution debate around the nation. The Associate Press rated it the top story of 1999. Since then, efforts to discredit evolution have intensified with conflicts raging in county school boards and state capitals. For much of the last 2 decades, the issue has been quintessentially local. But the May 10 briefing could represent a return to a national stage.
Leading Lights and Heavy Hitters
How well did the briefing succeed in reaching its target audience? Although only about 50 people attended, about a dozen members of Congress were involved - including 2 from the House Science Committee. These members served as honorary "hosts" for the briefing or introduced the speakers. Rep Charles Canady (R-Florida), chairman of the Subcommittee on the Constitution, arranged for the use of a House Judiciary Committee hearing room. Sen Sam Brownback (R-Kansas) and Rep Tom Petri (R-Wisconsin) warmly introduced several of the speakers. Petri is first in line to become chairman of the House Committee on Education and the Workforce at the end of this year. Thus, the committee responsible for federal education programs may be run next year by a man who expressed his hope for a "swelling chorus" of support for "intelligent design" theory.Those who attended the briefing were treated to a 3-hour primer on ID creationism from some of the movement's best-known advocates, including Whitworth College philosophy professor Stephen Meyer, Lehigh University biology professor Michael Behe, and University of California law professor Phillip Johnson. All are fellows of the Discovery Institute's Center for the Renewal of Science and Culture (CRSC). Joining them was another CRSC fellow, Nancy Pearcey - the former executive editor of Breakpoint, a conservative talk radio show hosted by born-again Watergate figure Rev Charles Colson, with whom Pearcey writes a regular column.
A "Purely Scientific" Debate
Most of the ID advocates were excellent communicators. They stayed away from highly technical jargon except to amaze their audience with the incredible complexity of life. They transformed the listeners' amazement into laughter at scientists' trying to explain this complexity as the result of random, evolutionary processes. They led the audience to the "obvious" conclusion that life could only be the handiwork of an intelligent designer. Consider it Occam's razor run amok: confronted with 2 explanations, one that appears dizzyingly complicated and improbable, and another, disarmingly simple, choose simple. Choose design.They did not thump Bibles. They did not try to convince the audience that dinosaurs are the "behemoth" of the Book of Job nor did they seek to explain that the Grand Canyon was formed during the Noachian flood. The IDCs voiced their acceptance of the depth of geologic time, modern genetics, even certain aspects of evolution itself. In fact, IDCs not only accept the advances of science, they argue that those advances have revealed a universe of physical and biological systems so complex that they could not possibly have come from evolutionary processes. Indeed, one theme was how "shocked" scientists have been by their discoveries of the awesome complexity of living systems. Shocked and disheartened, because their outmoded theories such as Darwinian evolution - adequate perhaps for the limited knowledge of the 19th century - cannot handle that complexity. This approach cleverly places ID theory at the cutting edge of scientific discovery while relegating Darwin to the dustbin of history.
Intelligent design, they said, is one side of a debate between 2 competing, empirically derived scientific theories - a debate, they claimed, that does not include religion. In their view, they are engaged in an open-minded investigation to follow the empirical evidence about life on earth wherever it leads. They contrast such openness with a rigid scientific orthodoxy that forcibly constrains explanations to purely natural phenomena, disallowing explanations that involve a higher intelligence. However, the tone of the Congressional briefing does not resonate with articles published by ID's "leading lights" in the nonscientific literature. For example, Pearcey wrote in the May 22 issue of Christianity Today: "Clearly, while [intelligent design theory] does not require any theological presuppositions, it has theological implications: It is resolutely opposed to the atheistic, purposeless, chance view of evolution taught in the power centers of science."
The speakers also tarred evolutionary theory with the controversial findings of social scientists who apply Darwinism to human interactions. Pearcey shocked the audience with a recent book that asserted rape was a natural male impulse driven by the need to confer evolutionary advantage. She also blamed Darwinism for the excesses of popular culture, quoting lyrics from a current hit song: "You and me, baby, ain't nothin' but mammals, so let's do it like they do on the Discovery Channel."
Ironically, the IDCs accept the achievements of science and indeed place their theory at the pinnacle of modern knowledge, but also demonize both the scientists who made those advances and the naturalistic method by which the advances were achieved. At the briefing Johnson replayed the portrayal of scientists from his popular books as an elite priesthood jealously guarding the power and prestige garnered from the ascendancy of their Darwin-inspired creation myth, having deposed the church's priests. There is a disconnect between the pains they take to portray the debate between ID and evolution as purely scientific and this separate line of argument portraying Darwinism as a religion.
The Political Landscape
I have previously asserted (Geotimes, October 1999) that the events in Kansas must serve as a wake-up call for scientists to get involved in their local school boards and in local and state governments. But I also suggested that they do so with their eyes open to the political landscape. IDCs are an important part of that landscape, and they have a sympathetic audience for their populist portrayal of scientists as an elite responsible for societal perversion. "Intelligent design" will be even more a part of the landscape if its partisans succeed in convincing the often warring factions among anti-evolutionist camps to unite under their big tent.Why is this briefing so important to those interested in quality science education? The Discovery Institute chose to hold its briefing at the same time that both the House and Senate were actively considering legislation to overhaul federal K-12 education programs. Scientific societies and other interested groups faced serious challenges as they tried to retain provisions in new federal legislation which supports and strengthens science and math education. If anti-evolutionists move into the Congressional arena and gain support from leading members of Congress, good science will face an even tougher challenge. Their efforts threaten to erode science education at the very moment when our technology-based society needs it more than ever.
For a summary of the May 10, 2000, Congressional briefing, visit www.agiweb.org/gap/legis106/id_update.html.
[Adapted with permission from David Applegate's column in Geotimes 2000 Jul; 45 (7): 12, 58.] David Applegate directs the American Geological Institute's Government Affairs Program and is editor of Geotimes.
Darwinism in "Crisis" - Again
When I heard of a conference that would introduce a scientific means of proving divine intervention in the natural world, thereby falsifying evolution, I knew I had to be there. So, on the evening of December 1, 1999, I headed off to La Mirada, a suburb of Los Angeles, to witness "Darwinism in Crisis - The New Challenge From Intelligent Design Theory".
The event was presented by the Master of Arts program in Christian Apologetics of Biola University (formerly the Bible Institute of Los Angeles). When all was said and done, it was quite clear that the purpose of the evening was to provide Christian apologetics and not science. We were to meet in an 800 seat lecture hall, but 1800 people showed up. The overflow was moved to the gymnasium where a closed circuit TV link had been set up.
By the time I settled into my seat in the bleachers overlooking the Biola Eagles' basketball court, the greetings and introductions had been completed and Phillip E Johnson, professor of law at UC Berkeley and author of Darwin on Trial, was holding forth on his idea of the Wedge. The Wedge is Johnson's strategy for separating science from philosophical naturalism, which he insists is the only basis upon which evolution could be accepted. Once he, as the sharp tip of the Wedge, has exploited the philosophical flaws in atheistic evolution to undo its death grip on modern theories of origins, others - scientists, philosophers and theologians, the wide end of the Wedge - would rush in to fill the void with a more "God-centered" theory.
Representatives of the wide end of The Wedge followed Johnson to the podium. A scheduling snafu caused the cancellation of the next planned talk, "DNA by Design", by Stephen C Meyer, PhD. I was disappointed to miss one of the 2 scheduled scientists. After all, I had come to see a scientific falsification of the theory of evolution. Someone remarked that to demonstrate that there was real science going on there would be slides and a laser pointer.
Paul A Nelson, PhD, a developmental biologist, was next, with a talk on "Intelligent Design and the Cambrian Explosion". He began with a chart illustrating Darwin's prediction that the history of life should exhibit ever-increasing diversity. He then compared it to his own bar graph showing the diversity of phyla as greatest during the Cambrian, then reducing and holding constant until the present. "There will never be an explanation", he insisted, for the paleontological record's being at such odds with Darwin's theory. No mention was made of the poor quality of the Precambrian and Cambrian fossil record nor of what including classes, orders, families, genera, and species might do to his bar graph nor of any number of evolutionary factors that are relevant to such a discussion. Nor did Nelson discuss how evolutionary biology has changed and matured since Darwin's early formulation of the theory.
He followed up with an argument from his own area of expertise. He contended that the genetic mechanisms that control cell differentiation and organization in a complex animal must have been in place and fully functional before the evolutionary processes that theoretically created them could have any effect. This is the same sort of cart-before-the-horse argument as Michael Behe's irreducible complexity, except at a larger scale - and it has the same flaws. There is no recognition of the fact that nature rarely gets from point A to point B via a straight line. A bat's wing, for example, did not develop as a wing one bone at a time. It was adapted from an arm for climbing, which in turn was adapted from a limb for crawling, which in turn was adapted from a fin for swimming.
Nelson's talk was to the extent of the scientific discourse for the evening. I was left with the impression that the closest we had come to real science was indeed the inclusion of slides and a laser pointer. That joke was not so funny after all.
Philosophers JP Moreland and John Mark Reynolds completed the program with talks on "Intelligent Design and Human Personhood" and "Intelligent Design: The History of a Concept", respectively. Moreland expounded on the idea that atheistic evolution is in direct opposition to human dignity, justice, and human rights. Reynolds described how society had come to be in the evil grip of such a vile concept as godless naturalism. I heard no new insights. There was no scientific proof of anything.
It is worth noting that the common thread of all of these talks was that the theory of evolution is necessarily atheistic and is therefore the cause of all of the major ills of Western society. Whether this is a straw man argument cynically used to whip up the faithful or an honest misunderstanding of the nature of science, the result is the same. There will be no easing of the passionate opposition to the teaching of evolution until this concern is effectively addressed.
The event was presented by the Master of Arts program in Christian Apologetics of Biola University (formerly the Bible Institute of Los Angeles). When all was said and done, it was quite clear that the purpose of the evening was to provide Christian apologetics and not science. We were to meet in an 800 seat lecture hall, but 1800 people showed up. The overflow was moved to the gymnasium where a closed circuit TV link had been set up.
By the time I settled into my seat in the bleachers overlooking the Biola Eagles' basketball court, the greetings and introductions had been completed and Phillip E Johnson, professor of law at UC Berkeley and author of Darwin on Trial, was holding forth on his idea of the Wedge. The Wedge is Johnson's strategy for separating science from philosophical naturalism, which he insists is the only basis upon which evolution could be accepted. Once he, as the sharp tip of the Wedge, has exploited the philosophical flaws in atheistic evolution to undo its death grip on modern theories of origins, others - scientists, philosophers and theologians, the wide end of the Wedge - would rush in to fill the void with a more "God-centered" theory.
Representatives of the wide end of The Wedge followed Johnson to the podium. A scheduling snafu caused the cancellation of the next planned talk, "DNA by Design", by Stephen C Meyer, PhD. I was disappointed to miss one of the 2 scheduled scientists. After all, I had come to see a scientific falsification of the theory of evolution. Someone remarked that to demonstrate that there was real science going on there would be slides and a laser pointer.
Paul A Nelson, PhD, a developmental biologist, was next, with a talk on "Intelligent Design and the Cambrian Explosion". He began with a chart illustrating Darwin's prediction that the history of life should exhibit ever-increasing diversity. He then compared it to his own bar graph showing the diversity of phyla as greatest during the Cambrian, then reducing and holding constant until the present. "There will never be an explanation", he insisted, for the paleontological record's being at such odds with Darwin's theory. No mention was made of the poor quality of the Precambrian and Cambrian fossil record nor of what including classes, orders, families, genera, and species might do to his bar graph nor of any number of evolutionary factors that are relevant to such a discussion. Nor did Nelson discuss how evolutionary biology has changed and matured since Darwin's early formulation of the theory.
He followed up with an argument from his own area of expertise. He contended that the genetic mechanisms that control cell differentiation and organization in a complex animal must have been in place and fully functional before the evolutionary processes that theoretically created them could have any effect. This is the same sort of cart-before-the-horse argument as Michael Behe's irreducible complexity, except at a larger scale - and it has the same flaws. There is no recognition of the fact that nature rarely gets from point A to point B via a straight line. A bat's wing, for example, did not develop as a wing one bone at a time. It was adapted from an arm for climbing, which in turn was adapted from a limb for crawling, which in turn was adapted from a fin for swimming.
Nelson's talk was to the extent of the scientific discourse for the evening. I was left with the impression that the closest we had come to real science was indeed the inclusion of slides and a laser pointer. That joke was not so funny after all.
Philosophers JP Moreland and John Mark Reynolds completed the program with talks on "Intelligent Design and Human Personhood" and "Intelligent Design: The History of a Concept", respectively. Moreland expounded on the idea that atheistic evolution is in direct opposition to human dignity, justice, and human rights. Reynolds described how society had come to be in the evil grip of such a vile concept as godless naturalism. I heard no new insights. There was no scientific proof of anything.
It is worth noting that the common thread of all of these talks was that the theory of evolution is necessarily atheistic and is therefore the cause of all of the major ills of Western society. Whether this is a straw man argument cynically used to whip up the faithful or an honest misunderstanding of the nature of science, the result is the same. There will be no easing of the passionate opposition to the teaching of evolution until this concern is effectively addressed.
Hammed!
I've been Hammed! Answers in Genesis (AIG) Executive Director Ken Ham has taken me to task for my keynote address to Dinofest '98 in Philadelphia. My talk was about American scientific illiteracy (extending to over 95% of adults), how the media contribute to it, and some remedies for the situation. I have given my talk perhaps 25 times from Limestone, Maine, to Long Beach, California, and the usual response I have had is "terrific", "great", "funny". But Ham did not like it, writing in the Answers in Genesis Newsletter (1998: 8) that I was "rather emotional ... critical, bitter, and intolerant of any view that differed from [my] own concerning evolution and dinosaurs - including a tirade against many beliefs, including creationism." Emotional? Well, I'd rather say that I was impassioned. Critical? Yes, but of the media - television in particular. Bitter and intolerant? Maybe I was, but not of creationism, UFOlogy, astrology, or a host of other pseudosciences, but of scientific illiteracy, which lets them flourish. But if Ham somehow equates creationism with scientific illiteracy, who am I to object?
I was "Hammed" because the good sense, reason and science literacy I call for are threats to creationists. They fear these, for their own tirades (or "battles", as they like to call them) against evolution will be less compelling if their audiences acquire these attributes. My point in writing here is to note just how sensitive Ham and his kind are, and how he twists reality to fit his own needs. He uses a common strategy on me, and a closer look at what he did may help us to understand how these folks work. Basically, I was simply a good excuse to rouse the troops.
In fact, Ham purposefully confuses the point of my talk. My talk was not about dinosaurs or even evolution. I know nothing much about dinosaurs, although I am an evolutionist through and through. Because I only had 45 minutes rather than my usual hour and a quarter, I reduced my comments about almost everything except science illiteracy, the media hyping of pseudoscience, and what we can do to get reasonable science incorporated into television programs. One slide stated that religion, science, and pseudoscience are different ways to view the world, but I made no comment about religion at all. I showed another slide listing some paranormal beliefs, and creationism was on the list. But again I made no comment about it. My example of pseudoscientific ignorance was UFO beliefs, because that is a very funny subject; whereas, by contrast, I find little that is humorous about creationism. I focused on scientific illiteracy in this country and how the media contributed to it with a variety of fraudulent programming, including "The Mysterious Origins of Man", a television program (and now a video series) that every good creationist should object to as much as evolutionists should (see NCSE Reports 1995; 15 [4]: 1 and sidebar). I suggested how the media could present science in a reasonable, compelling, and profitable way, if it cared to.
Ham "Hammed" me on that too. He implores his readers to "join the battle" against us evolutionists who are trying to use "the media to brainwash the public in evolutionary thinking." (Ironically, Ham's own article ends with an appeal for creationists to use dinosaurs to reach people about creationism.) He emphasized that I wanted to recruit the media aggressively "to ensure that writers present evolution as science and as fact - and to do it often." Not true. What I said was that television writers, in particular, should present science - and present it often. Insofar as evolution is part of science, it should be presented too. But I am far more concerned with getting people to understand how science works than in presenting evolution. That will come when the demon-haunted world is no more.
References
These references, including the last one about creationism, put my views about scientific literacy, pseudoscience, and the media on record.Ham K. The dinosaur agenda. Answers in Genesis Newsletter 1998 June; 5: 8.
Lipps JH. The decline of reason? In: Scotchmoor J, McKinney FK, editors. Learning from the Fossil Record, Paleontological Society Special Papers 1996; 2: 3-10.
Lipps JH. The media, trash science and paleontology. Palaeontologica Electronica 1998.
Lipps JH. Beyond reason - Science in the mass media. In Schopf JW, editor. Evolution, Facts and Fallacies. San Diego (CA): Academic Press, 1999. p 71-90.
Lipps JH. Paleontology challenged! Palaeontologica Electronica 1999.
In Memory of Bob Schadewald
Bob was a technical writer by profession, but he was known to NCSE members and many others as a researcher of the scientifically quirky. The creation/evolution issue occupied much of his time, but his true specialty was the turn-of-the-century flat-earth, geocentric, and hollow-earth movements. It would not be an exaggeration to say that he was truly the authority on these early pseudosciences, about which he wrote several articles.
He assembled an unusually complete library of materials on these enthusiasms, including original books and pamphlets as well as copies of obscure and one-of-a-kind items archived at libraries in the US and abroad. Bob was a bibliophile's bibliophile: whenever he visited a city, he inevitably would check the library's holdings, and he always made the rounds of used book stores. Bob's library reflected his fascination with how science could be distorted, spun around, and turned inside out to justify false claims, whether those of special creation, or the even more bizarre "theory" of a hollow earth. He delighted in pointing out similarities in how geocentrists, flat-earthers, and creationists marshaled their arguments. One of his prize possessions was a framed certificate declaring him a member of the International Flat Earth Society, headed by Charles K Johnson, of Lancaster, California. He was always happy to relate the story of how Johnson rescinded his membership after he discovered that Bob possessed "spherical tendencies".
When I broke the news of his death to various friends and associates, the universal response was dismay that Bob had died so young, depriving us of his intelligence, his knowledge, his wit, and his company. "He knew so much!" was a common lament, and indeed, Bob had a wealth of information, seemingly retrievable on a moment's reflection. I know that I relied a lot on his mental encyclopedia as well as on his keen insight into the people and ideas of the creationism controversy.
For Bob, more than any of us, personally knew and was friends with many of the people whose ideas we disagree with. Readers of RNCSE (and its predecessor, NCSE Reports, which Bob once edited) will recall Bob's published analyses of quadrennial International Creationism Conferences, which he faithfully attended. There was never any question that he disagreed profoundly with the "research" presented at these meetings, and he gave no quarter in vigorous debate with the creationists participating in these meetings, but he saw no contradiction in going out afterward for a beer with these same adversaries. He made a distinction between creationists whom he considered sincere and who treated the scientific data on evolution fairly (even if they rejected it), and others whom he considered "snake-oil salesmen". When one creationist recently lost most of his personal library in a fire, Bob generously boxed up duplicate copies of his books on the creation/evolution controversy and shipped them off. There are a number of creationists who personally will miss Bob, even though they may not miss his barbed criticisms of their scientific statements or his astute dissections of their logic.
Bob resigned from the NCSE Board of Directors in the mid-1990s, citing increased demands of work as well as some personal reasons. But he remained an "on-call" advisor to me and other Board members, and was a strong proponent of NCSE to the general public. He maintained informal email connections to many other "creationism fighters", sharing information and suggesting strategy up until the last week of his life.
Once, after a typically long NCSE board meeting, a group of us had gone out for dinner. Immersed as we were in the creation and evolution controversy, after a few drinks, we started talking about creationist "scientific models" — laughing about the convolutions of data and theory required to accommodate scientific data within a 6-day creationist model. Much of the conversation consisted of "and can you believe that they actually think…?" as we regaled one another with examples of creationists' apparent ability to believe at least 7 impossible things before breakfast. We were having a pretty good time at the opposition's expense, when Bob looked up and said, "You know, somewhere, there's probably a bunch of creationists sitting around a table, drinking beer, and saying, 'those evolutionists! Can you believe they actually think…?'"
We're going to miss him.
Of Mousetraps and Men: Behe on Biochemistry
In Darwin's Black Box: The Biochemical Challenge to Evolution, biochemist Michael Behe claims that biochemical systems exhibit a special kind of complexity - irreducible complexity - that cannot possibly have evolved and must have resulted from intelligent design. Like other intelligent-design creationists, Behe is vague about both the identity and methods of his intelligent designer, though he does distinguish between the hypothesis of natural design (by space aliens, perhaps) and that of supernatural design (1996, 248-9).
As Behe is aware, postulating intelligent design by space aliens only postpones a confrontation with the problem of the origins of complexity. After all, who designed the designers? Thus the unwary reader is pointed in the direction of a supernatural, undesigned designer. But if you were puzzled by biochemical complexity in the first place, this latter hypothesis, involving as it does an unknown supernatural being that employs unknown materials and methods, can hardly result in a net reduction of mystification.
Luckily we do not have to settle this matter. It turns out that Behe's intelligent design hypothesis is the result of his failure to consider relevant natural processes when trying to account for the origins of biochemical complexity. This problem arises in turn because Behe thinks about biochemical complexity with the aid of a misleading mechanical analogy - the well-designed mousetrap. The mechanical mousetrap is to Michael Behe what the mechanical watch was to William Paley. And it goes without saying that machines have designers.
So how should we think about design and designers? We will argue first that the historical process of the intelligent human design of technological artifacts, such as mousetraps, needs to be sharply differentiated from the hypothetical magical process of supernatural design and creation ex nihilo (literally from nothing). In fact, Behe's case derives its appeal from a failure to examine the details of the human design process. Naturally, he provides no details whatsoever of the hypothetical supernatural design process. Secondly, we will show why the mousetrap analogy fails to do justice to the richness of biochemical complexity. And thirdly, we will offer a conceptual framework that explains the origins of the irreducible complexity Behe finds so mysterious (see also Behe 2000). The key, as we shall argue, is that most real biochemical systems exhibit a type of complexity that we term redundant complexity: a form of complexity that results from natural evolutionary processes amenable to scientific study.
The Mousetrap Model of Biochemical Complexity
Behe's central thesis is that the biochemical systems we find in living organisms manifest irreducible complexity. He further contends that processes of the kind invoked in evolutionary biology cannot explain the origin of irreducibly complex biochemical systems. Behe explains:By irreducibly complex I mean a single system composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning. An irreducibly complex system cannot be produced directly (that is, by continuously improving the initial function, which continues to work by the same mechanism) by slight, successive modifications of a precursor system, because any precursor to an irreducibly complex system that is missing a part is by definition nonfunctional (1996: 39).
Behe contends that although intelligent design processes of the kind we find in engineering, for example, can give rise to irreducibly complex systems, evolutionary processes cannot.
Behe employs an analogy with well-designed mousetraps. A mousetrap has several components, all of which are necessary for catching mice. A precursor "trap" that lacked one of the components - the spring, the trigger, or the platform, perhaps - could not trap mice. Lacking even minimal function, it could not be improved through incremental adaptive evolution to become a functioning trap. We already know that mousetraps require intelligent human designers. Behe argues that functioning biochemical systems are like mousetraps. They could not have evolved through incremental adaptive evolution, and must be the products of super-human intelligent design. This argument, like all design arguments, has a surface plausibility. It is too bad that those who rely on design arguments have never taken the time to think clearly about what is actually involved in the intelligent human design of technological artifacts.
The Origin of Artifacts
It is essential to differentiate between the actual behavior of intelligent human designers on the one hand and the hypothetical action of a supernatural being on the other hand. Human engineers do not create or manufacture anything ex nihilo, nor are the processes of design secular miracles; to suggest otherwise is misleading. For ordinary objects like mousetraps, we can infer that they are designed without having any knowledge of their designer. Why? Because we all know that mousetraps are artifacts, and by definition artifacts have designers.But, by studying the history of artifacts and engaging in reverse engineering, we can often uncover the identities of actual human designers, as well as the methods and materials they employed. That is why it is important to study the processes of human design, and not just the design itself. Can we analogously study the design process of the hypothetical supernatural designer? No proponent of supernatural design - not St. Thomas Aquinas, not Archdeacon Paley, not Michael Behe and his numerous sympathizers - has ever offered the slightest clue about how this could be done scientifically.
Intelligent design theorists, noting that various biochemical systems give the appearance of being designed, aim to argue that they are, like artifacts, actually the products of design. However, if they are not like artifacts - if the appearance of design is deceiving - then all bets are off. Although a biochemical system might give the appearance of being designed, the conclusion that the system actually results from design could be made evidentially respectable if, for example, we can find some compelling scientific evidence concerning the methods and materials employed, and also some compelling historical evidence concerning the identity of the designer.
Why should this be so? The reason lies in a fundamental difference between things such as mousetraps or watches, on the one hand, and things such as biochemical systems, on the other. Mousetraps and watches are antecedently known to be artifacts, and hence to have human designers (even if their identities and methods are obscure). For these objects, the question of design can often be safely separated from the questions of how designed and by whom.
But in the case of the alleged intelligent design of biochemical systems, these questions are all inextricably intertwined precisely because it is not known antecedently that biochemical systems result from deliberate design by a non-human agent (or agents) of supernatural origin. The very claim of design itself requires evidential justification. Providing evidentially grounded answers to the questions of how and by whom these systems were designed would simultaneously provide powerful evidence that the systems were indeed designed - a matter sorely in need of justification. This issue is made all the more acute because naturalistic evolutionary hypotheses exist to explain the same features that lead Behe to postulate a designer; one is presented below. For this reason, the features of biochemical systems that Behe points to cannot simply be viewed as the registered trademark of the creator or the hallmark of design. Behe has made an extraordinary claim, and its validation will require extraordinary evidence. Behe makes no attempt to meet this evidential requirement.
Moreover, in his argument Behe cavalierly ignores common facts about the human design process, which, like biological evolution itself, involves descent with modification. The intelligent human design of artifacts is frequently a historical process resulting from the generation of variation on existing technological themes along with selective retention of specific variants for further elaboration. Human engineers have long known that the problem-solving process is a historical, tinkering, trial-and-error process.
Indeed, it is the ability to produce multiple variants on themes, by varying parameters, that makes modeling and simulation such a powerful tool in the design of technological artifacts such as aircraft (Vincenti 1990). Even at the dawn of powered flight, the Wright brothers built, tested, and discarded numerous models in wind-tunnel tests. Many variants based on existing glider designs were tried, but only a few were chosen and selected for further elaboration. The ultimate fruit of this trial-and-error process was a powered machine adapted to an aerial niche! It was not magically created by some human intellectual whirlwind using pieces of junkyard scrap.
The concept of supernatural intelligent design derives at least some of its appeal from the fact that we humans have actual experience of the intelligent design of artifacts. But when what is involved in human design is properly understood, do we really want to understand the hypothetical supernatural design process by analogy with the bungling, tinkering, trial-and-error process of our own experience? And if the supernatural process is different from the human process, how is it different? And how could we settle disputes between rival hypotheses about the details of the supernatural design process? Until these issues are addressed, biochemistry's mysteries will not be solved through the invocation of supernatural design, because until they are dealt with, the appeal to supernatural design will be effectively no different from the claim that it all happened by magic. If ever there was an explanatory black box, this is it!
Perhaps our point is now clear. But if it is not, let us elaborate using some examples given by Gary Cziko:
In 1793, Eli Whitney's cotton gin that removed seeds from short-stapled cotton was based on the Indian charka, which had been in use for thousands of years to remove seeds from long-stapled cotton. Joseph Henry's electric motor of 1831 copied many of the mechanisms involved in the steam engine. The development of the first transistor at Bell Laboratories in 1947 ... owed much to the work of German physicist Ferdinand Braun who, in the 1870s, found that certain crystals conduct electricity in only one direction (1995: 163).
What at first glance might appear to be an ahistorical special human creation is really an artifact belonging to an historical lineage, where new artifacts result from the same variation-and-selection processes that are the staple of evolutionary explanations.
To see how this works, consider intelligently designed jet engines. These are clearly a different species of technological artifact from intelligently designed water-wheels. Yet over the last three hundred years we can trace a line of descent from water wheels to water turbines, and then from water turbines to steam turbines, gas turbines, and jet engines, with variation-and-selection processes playing important roles in all the major engineering transitions.
Needless to say, jet engines did not descend in a simple linear fashion from water wheels. Rather these artifacts emerged through processes involving horizontal transfers of modules from other evolving technological lineages (for example, fuel technologies, metallurgical technologies, and so on). The new modules were further modified as they were gradually incorporated through trial-and-error processes leading to the development of symbiotic relationships.
Interestingly, although there are some obvious and important differences between technological and biological evolution - the former is best explained in terms of intelligent (human) design, whereas the latter is not - they do not differ with respect to having benefited from horizontal module exchanges.
Horizontal transfers play an important role in biological evolution. Modules evolving in one lineage can be transferred to other lineages, where they typically undergo further evolutionary modification. For instance, changing the example from jet engines to eukaryotic cells, evolutionary biologists now see the mitochondrial power plants as the fruits of a symbiotic union between at least two distinct prokaryotic lineages - the integrated endosymbiotic whole is greater than the sum of its prokaryotic parts.
Nor should the evolutionary theorist ignore horizontal plasmid exchanges by means of which genetic information in one bacterial lineage can find its way into another, distinct, lineage. On a larger scale, there is, of course, horizontal exchange through hybridization. In this process, of great importance in plant evolution, first-generation hybrids show a genuine mixture of characteristics from the distinct parental lineages.
And what of the origin of mousetraps? Variation-and-selection processes have played an important role here too. Since the US Patent Office opened in 1838, it has granted more than 4400 mousetrap patents. Currently, about 40 new mousetrap patents are issued each year. Ten times that many patents are turned away, mostly because they are not minimally functional. The Patent Office mousetrap taxonomy recognizes 39 subclasses, including "Impalers", "Smiters", "Swinging Strikers", "Choking or Squeezing", "Constricting Noose", and "Electrocuting and Explosive" (Hope 1990: 92)
Devices that kill mice by hitting them have a long and interesting technological evolutionary history - see Hornell (1940). The spring-loaded trap discussed by Behe appeared in the 1890s, and was patented in 1903 (nr. 744379) by John Mast, a Pennsylvania coleslaw manufacturer with a serious rodent problem. The spring-loaded trap did not result from design and creation from nothing - a secular miracle in Pennsylvania. Rather, Mast had studied existing mousetrap patents and had borrowed from 5 or 6 of them - thus showing the importance of horizontal information transfers - before filing his own patent application in October 1899 (Hope 1990: 94). Behe's mousetrap is in fact a technological hybrid, descended with modification from earlier traps in a complex historical evolutionary process. Although the mousetrap is intelligently designed, it did not appear by a magical, ahistorical process of special creation, the details of which are forever hidden from public view!
Biochemical Complexity and the Mousetrap Analogy
But what of the mousetrap analogy of biochemical complexity? Here we will present some examples from biochemistry that call into question the general biochemical relevance of the mousetrap analogy. We will argue first that Behe's mousetrap analogy leads him to ignore a crucial aspect of the biochemical complexity we observe in nature: the phenomenon of redundant biochemical complexity. Redundant biochemical complexity represents the biochemical and molecular footprints of evolutionary processes in action. Having explained and illustrated this concept, we will then argue that redundant complexity provides the key for a natural, evolutionary understanding of the origins of irreducible complexity. We do not pretend to have a complete account of evolutionary biochemistry. We suspect that the details will eventually emerge from continuing scientific research. But rather than speculate about these matters, we will focus instead on what we do know about biochemical systems.While biochemical complexity has many sources, one of the key concepts underlying our current understanding of biochemical evolution is that of gene duplication, a process whereby a gene is doubled in a genotype. As a result of this process, one gene can continue the old function, while the duplicate is freed up to be co-opted to serve novel functional ends - the duplicate gene acquires mutations that change its activity. These mutations may be preserved or eliminated through the operation of natural selection. If preserved, these mutations can lead to new functions. More importantly for our purposes, gene duplication is also a central evolutionary source of some of the redundant complexity we actually observe in biochemical systems (Shanks and Joplin 1999). So what is redundant biochemical complexity?
We see redundant complexity when we notice that many actual biochemical processes do not involve simple linear sequences of reactions, with function destroyed by the absence of a given component in the sequence. Instead, they are the product of a large number of overlapping, slightly different - hence redundant - processes. Redundant complexity is also embodied in the existence of back-up systems, which can take over if a primary system fails. Finally, redundant complexity is observed in the phenomenon of convergent biochemical evolution, wherein systems with different evolutionary histories, perhaps using different mechanisms, nevertheless achieve similar biochemical functions.
Redundant complexity turns out to lie at the heart of the stability that biochemical processes manifest in the face of perturbations that ought to catastrophically disrupt systems like Behe's well-designed, minimalist mousetrap - the absence of any component of which should render the system unable to perform its function. To understand redundant complexity better, it will help to look at some examples.
Redundant Pathway Complexity
If we examine the central catabolic pathway of glycolysis (the interconnected series of reactions by which glucose is broken down to release usable energy), it looks superficially as though the product of one reaction in the series is required as the substrate for the next reaction in the sequence. Thinking of glycolysis on the mousetrap model, one would expect that removing one component - enzyme, substrate, or product - would shut down the pathway and prevent the continual production of energy. In fact, almost every step in this pathway is redundantly complex. As an example, let us look at a key step, the production of glucose-6-phosphate from glucose, catalyzed by the enzyme hexokinase.Not only does hexokinase activate the relatively stable glucose (Bennett and Steitz 1978), but it is a multipurpose enzyme that in part controls the rate of the first part of the glycolytic pathway by directing the chemistry of glucose either to build up more complex molecules (anabolism) or to harvest the energy stored in glucose (catabolism). The direction of chemical activity is dependent only on the concentration of the substrates, products, and various components of the pathway (Voet and Voet 1995).
One might assume, therefore, that here we have a good example of Behe's irreducible complexity. Remove the enzyme and the reaction should stop. But this intuition rests only on a superficial characterization of this step in the pathway. Looking at the fine details -- where the devil proverbially lurks - reveals an unexpected complexity in what initially appeared to be a simple, straightforward chemical situation.
In typical vertebrate tissue, redundant complexity is manifested in the existence of several different variants (isoforms) of hexokinase. All of these are present, as a result of gene duplication and differential expression, in varying proportions, in different tissues. The proportions of the variants differ for the specialized functions of the different tissues in which they are present, depending on whether the tissue requires rapid utilization of energy (as in muscles) or is involved in converting glucose into the storage form glycogen (as in the liver). Removal of a given variant of hexokinase does not disrupt glycolysis, although it may have an effect on the efficiency with which a function is achieved. So there is redundant complexity here, in the first, seemingly simple and straightforward, step of the glycolytic pathway.
Each of the other components of the rest of the glycolysis pathway manifests similar redundancies. Remove glucose, and the pathway can utilize numerous other hexose (6 carbon atom) sugars to supply the next product. Knock out one enzyme variant, and the other variants in the tissue can take over its function - maybe not quite as efficiently, but as Behe concedes, efficiency can be improved by natural selection over evolutionary time. There are back-up systems too. For example, if all the variants of hexokinase were removed, there are alternative pathways, such as the pentose phosphate pathway, that can supply the needed products (Martini and Ursini 1996).
It is a hallmark of many evolved biochemical systems that there are typically multiple causal routes to a given functional end, and where one route fails, another can take over. The existence of variants of a given enzyme are evolutionary legacies - legacies by means of which one and the same enzyme can be adapted to serve different specialized functions in different specialized tissues.
Genetic Knockout
Another way in which we can see the general inadequacy of the mousetrap analogy of biochemistry is simply to remove specific sections of an organism's genome. This procedure has recently been applied to mammals. Researchers can now target a specific gene in mice and "knock it out" (Travis 1992). Such knockout mice are valuable models for human diseases in gene function experiments. However, such mice do not always give the expected result - they do not exhibit the predicted functional deficits - due to the type of redundant complexity we have been discussing.One example concerns the gene p53, which was originally identified as a tumor suppression gene, but has subsequently been found to be involved in a number of fundamental cell processes. For example, it plays roles in gene transcription, the cell cycle, programmed cell death (apoptosis), DNA replication, and DNA repair processes (Elledge and Lee 1995).
If you thought of this case as a genetic mousetrap, you might be tempted to think that the removal of this gene, involved as it is in all of these vital processes, would lead to catastrophic collapse of the developmental process - a bit like removing the spring, trigger, or platform from Behe's mousetrap. But this is not the case, since p53 knockouts in mice yield offspring that are viable and fertile, although susceptible to the early appearance of spontaneous tumors (Dowehower and others 1992). This suggests the following dilemma: either p53 is not required for embryonic development or there are redundant ways in which the function of the missing component is compensated for (Elledge and Lee 1995). The evidence at hand supports redundant complexity, since there are at least 400 proteins associated with the proper control of the cell cycle alone (Murray and Hunt 1993), and it would appear that some of these other proteins pick up the slack created by the missing p53. Such mice can still be caught in mousetraps!
Genomics
We are discovering more and more about the nature and role of redundant complexity. Consider the new field of genomics. The study of genome sequences has revealed some startling findings about the complexity and organization of biological organisms. The genome of the yeast Saccharomyces cerevisiae contains many redundant sequences. Fifty-three duplicated gene clusters, making 30% of the yeast genome, have been identified (Clayton and others 1997). Such findings concerning gene duplication lead to an interesting question concerning Behe's use of the mousetrap analogy. That is, how few genes does it take to maintain a free living organism? Experiments at Celera Genomics are currently underway to knock out all nonessential genes from Mycoplasma pneumoniae.If these experiments succeed, the resulting minimal organism will be noteworthy as a genuine example of a genetic version of Behe's mousetrap. If the organism really is genetically minimal, the absence of any component will be fatal. And such a minimal organism will be peculiar precisely because it will be a laboratory artifact - a drastic artificial modification of a redundantly complex natural system.
Redundant Origins of Irreducible Complexity
The existence of redundant complexity is evidence of the operation of evolutionary processes at the biochemical level. But it does not show that Behe is wrong to point to the existence of irreducible complexity. Let us suppose that some of his candidate examples of irreducible complexity are correct. Redundant complexity gives us the tools to explain the origins of what Behe found so mysterious. To see how redundant complexity might explain the origins of irreducible complexity, let us borrow an architectural image from A G Cairns-Smith, a biochemist interested in the origins of biochemical complexity (1986: 59-60).Consider a free-standing arch of stones. It manifests irreducible complexity in that the keystone at the top of the arch is supported by all the other stones in the arch, yet these stones themselves cannot stand without the keystone. In other words, all the component stones depend on each other. Take away any stone, and the arch collapses.
Notwithstanding this fact about arches, it is nevertheless possible to construct them in gradual stages. You cannot gradually build a self-supporting, free-standing arch using only the component stones, piling them up, one at a time. But if you have scaffolding - and a pile of rocks will suffice to support the growing structure - you can build the arch one stone at a time until the keystone is in place and the structure becomes self-supporting. When this occurs, the now redundant scaffolding can be removed to leave the free-standing structure.
The study of developmental processes suggests that an important biological role is played by removable scaffolding in the formation of all manner of elaborate structures, including body parts and neural pathways. For example, developmental scaffolding, in the form of an initial superabundance of cells, can be removed by programmed cell death (apoptosis). This process plays a crucial role in the developmental sculpting of such structures as fingers and toes (Campbell 1996: 980; Lewis 1995: 15).
Natural evolutionary processes give rise to the redundant complexity we observe in biochemical systems. But these redundancies may also provide, in concert with extant functional systems and structures, the biochemical scaffolding to support the gradual evolution of systems that can ultimately manifest irreducible complexity when the scaffolding is reduced or removed. By the operations of natural selection, some of these biochemical arches will be retained for further evolutionary elaboration, while others will be eliminated. In effect, irreducible complexity results from the evolutionary reduction of redundancy in redundantly complex systems - systems that are themselves the fruits of evolutionary processes.
In an earlier paper (Shanks and Joplin 1999), we argued that self-organizing chemical reactions - many of which are suitable for demonstration in the classroom or laboratory - can give rise to irreducibly complex chemical systems. Our claim here is that redundant complexity provides another natural evolutionary route to the same end. We are a long way from having to abandon natural science in favor of supernatural hypotheses concerning the origins of biochemical complexity.
Conclusions
Although there is much that we do not know about the biochemistry of living systems, and Behe points to some good examples, we do know that they are not like designed artifacts such as mousetraps. Behe's case against evolution is a good example of the perils of being trapped by a metaphor - a metaphor that Behe has not properly understood. A closer look at human intelligent design processes reveals not secular versions of theological design and creation ex nihilo, but instead complex manifestations of analogs of evolutionary processes - this time in the domain of the cultural evolution of technological artifacts. Descent with modification is as important in the origin of artifacts as it is in the origin of species.We have also argued that many evolved biochemical and molecular systems exhibit redundant complexity. This kind of complexity simultaneously accounts for the stability of evolved biochemical systems and processes in the face of even quite radical perturbations, for biochemical and metabolic plasticity, and, mainly as a result of gene duplication, for the co-optation of extant structures and processes in the course of evolutionary time to serve novel functional ends.
More importantly, redundant biochemical complexity points to the general biochemical inadequacy of the mousetrap analogy while providing a natural evolutionary basis for the appearance of biochemical systems manifesting irreducible complexity.
Of course, for some types of engineering problem, intelligent human designers build in redundancy and back-up systems. Perhaps Behe might want to argue that the resulting artifacts, with their engineered redundancy, suggest a more sophisticated design analogy. The trouble here is that naturalistic, evolutionary processes give rise to similar biochemical redundancies. And evolutionary processes do so without appeals to supernatural biochemical designers of unknown identity, using unknown materials and methods.
References
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Pandas Update
In 1989, Kenyon and Davis published the first edition of Of Pandas and People as a supplementary biology text. In both the first and second editions, the authors claim that there is scientific evidence against evolution in a number of fields of scientific research. Since 1995, I have searched the scientific literature in those fields identified in Pandas as being problematic for evolution and reported on it in our members' publications. As expected, a number of questions in the sciences were unanswered at the time of the original publication of Pandas in 1989. By the publication of the second edition in 1993, more of these issues were resolved, but new questions were also raised.
Once again this year, RNCSE presents a brief summary and a bibliography of recent works, organized to parallel the structure of Of Pandas and People. On each topic there is active and ongoing research in the appropriate sciences as well as a growing bibliography of resources for those interested in specific topics. By contrast, in the 11 years since the publication of the first edition of Pandas and the 6 years in which I have been preparing these summaries, the scientific triviality of the "intelligent design" theory is, and has been, manifest in the lack of any primary research reports based on "intelligent design" in the peer-reviewed scientific literature.chapter 1:
Before investigating the possible origin of life, one ought to know what it is. The difficulties of defining "life" are reviewed by Holmes (1998). Radetsky (1998) and Joyce and Orgel (1998) summarize current ideas about the origin of life.
The Martian meteorite still engenders debate (Kerr 1998a; Gibbs 1998). Several new studies (such as Bada and others 1998) indicate that the organic material in the meteorite is the result of terrestrial contamination. Research on the possible extraterrestrial organic materials in other meteorites continues. The Murchison meteorite contains over 70 different kinds of amino acids, many uniquely extraterrestrial (Pizzarello and Cronin 1998). Brainard (1998) speculates that even though Martian microbes may exist, they may be very scarce and hard to find on Mars.
Scientists are also reporting more evidence about the materials and conditions elsewhere in our solar system that could have supported the origin of life. Highly detailed pictures of Europa's surface by the Galileo spacecraft continue to reinforce the hypothesis that a watery ocean is hidden beneath the icy surface (Holden 1998). The paucity of craters on the surface is interpreted as showing that the surface is an active young surface (Kerr 1998b). Other evidence for an ocean is the detection of absorption bands in reflectance spectra indicating hydrated salts on the surface (McCord and others 1998). Evidence for induced magnetic fields is interpreted as evidence for subsurface oceans on both Europa and Callisto (Kivelson and others 1998). Svitil (1998) discusses the possibility of large amounts of methane and other organic compounds on Saturn's moon Titan.
As to the question of whether life could have arisen on planets elsewhere in the universe, astronomers continue to find evidence for extrasolar planets (Semeniuk 1998; Cowen 1998a). Most are inferred from observed wobbles in their stars' paths. Others are inferred from irregularities in a star's dusty disk (Cowen 1998b; Kalas 1998). One has been imaged directly (Leutwyler 1998). The known extrasolar planets now outnumber the planets of the solar system.
Researchers also claim to have found tiny nanobacteria in rocks and in the Martian meteorite. Other workers are skeptical of the existence of these organisms (Vogel 1998). Kajander and Ciftcioglu (1998) report on finding such ultramicroorganisms in biological materials.
Nitta and others (1998) report that ribosomal RNA can produce peptide bonds. Similarly, utilizing test-tube evolution, Zhang and Cech isolated a pure RNA pseudo-ribosome that could link amino acids together (Cohen 1998). Carmi and others (1998) report on "deoxyribozimes" (for example, a DNA molecule) that can act as an enzyme and cleave single-stranded DNA oligonucleotides. Unrau and Bartel (1998) report the creation, by test-tube evolution, of an RNA molecule that can synthesize a pyrimidine nucleotide from its phosphate, sugar, and base constituents.
Some theorists favor a high-temperature origin of life near oceanic hydrothermal vents (Balter 1998). Levy and Miller (1998) report that this is unlikely because the nucleotide bases are not sufficiently stable at such high temperatures. Huber and Wachtershauser (1998) claim that amino acids can be activated and condensed into peptides under conditions like those prevailing near vents. Another idea is that mineral surfaces may have aided in the production of polymers (Edwards 1998; Smith 1998; Parsons and others 1998). Along these lines, Luther and others (1998) describe a self-replicating chemical system involving solid support for the chemical templates that can increase the concentration of oligonucleotide analogues exponentially.
Poole and others (1998) describe a Darwinian model for the evolution of life from the late stages of the RNA world through to the emergence of eukaryotes and prokaryotes. In connection with this, Jeffares and others (1998) derive criteria for identifying ribozyme relics of ancient RNA structures in modern microorganisms and creating a model of the last ribo-organism before the advent of protein-directed catalysis.
A rich find of unicellular eukaryotic fossils along with bacteria have been found in 800-Ma-old rocks on Canada’s Victoria Island (Monastersky 1998b). South African researchers have found evidence that primitive unicells may have lived in soil on land 2000–2200 MaBP (Monastersky 1998a). Recent experiments suggest that multicellular colonies may evolve from unicells as a defense against predation. Unicellular predators found the colonies too big to ingest (Blackman 1998).chapter 2:
Genomes exhibit many diverse phenomena and genetic information is often stored in complex ways. A gene, for example, may be split into exons and introns, the latter being excised as "junk" when the gene is transcribed into messenger RNA. Similarly, some proteins that are produced by ribosomes consists of exteins and inteins, the latter being excised from the polypeptide chain to make the final form of the protein. Wu and others (1998) describe such a protein and its gene in the microbe Synechocystis. An added complication is that the gene itself is split into 2 parts found in 2 different parts of the chromosome. Each part codes for an extein and part of the one intein. Only after the 2 polypeptides are formed do they join to form the complete intein, which then excises itself to form the final protein molecule!
Pennisi (1998b) reviews the ways in which genomes can change, including transposable elements, shuffling or duplication of material, mutational hotspots, and inaccurate copying of 2- and 3- base repeats which may affect the function of neighboring genes. Max (1998) discusses pseudogenes, short and long interspersed elements, retroviruses, and retroposons as evidence for evolution. The numbers of multiple elements are still increasing in mouse species (Anonymous 1998); the house mouse has 3000 of them! Vogel (1998) and Pennisi (1998a) review modern ideas and experiments concerning the evolution of the genetic code. Van den Burg and others (1998) were able to utilize mutations to modify a bacterial enzyme to work at very high temperatures.
A number of papers dealt with sexual selection. Arnqvist (1998) discusses the possibility that the shape of male genitalia evolved under sexual selection. Evans (1998) tests the hypothesis that sexual selection produced the long tail streamers of male swallows, discovering that the length of the tail is governed by natural selection. Call duration in tree frogs may be used by females to select males with superior genetic quality (Welch and others 1998). In swordtail fish, females prefer larger swords (Rosenthal and Evans 1998). In stalk-eyed flies, females prefer males that have longer stalks (Wilkinson and others 1998). The long eye stalk condition is linked to the possession of a Y chromosome that suppresses the meiotic drive of a "selfish" X chromosome that biases the sex ratio in favor of females.
Landweber and others (1998) review the successes in ribozyme engineering using test-tube evolution. They list 2 dozen new ribozymes "evolved" either from some precursor RNA or from random sequences of RNA. Macbeath and others (1998) used test-tube evolution to redesign enzyme topology. Crameri and others (1998) describe DNA shuffling, a technique used to speed up test-tube evolution.
It is estimated that vertebrates have between 50 000 and 100 000 genes, while invertebrates have fewer than 25 000. Simmen and others (1998) estimate that the invertebrate chordate Ciona has about 15 000 genes. Evidence indicates that at least 2 rounds of polyploidy occurred in the vertebrate ancestors after the separation of Amphioxus and the craniates (Pebusque and others 1998; Postlethwait and others 1998).
The extensive data on microbial sequences point to the possibility that early in the evolution of life, before the 3 domains (Bacteria, Eukara, and Archaea) emerged, there was much horizontal transfer of genetic material (Pennisi 1998; Koga and others 1998; Woese 1998; Katz 1998). Miller (1998) discusses horizontal gene transfer occurring today, since it could allow genetically engineered microbes to pass their genes to other species in the environment with unintended results. Katz (1998) reviews the latest ideas on the evolution of eukaryotes. She presents evidence that the eukaryote archezoans, which do not possess mitochondria, have secondarily lost those organelles. Aravalli and others (1998) report that Archaea, originally considered to be confined to extreme environments, are much more widespread, being found in soils, lake sediments, marine picoplankton and deep-sea locations. Microbiologists have estimated that there are 5 x 1024 bacteria living on earth in the ocean, in the soil, beneath the surface, in the air, and inside animals. Soil and subsurface habitats account for 94%; the insides of animals account for only a fraction of 1 percent. In the oceans, any given bacterial gene is estimated to undergo an average of 4 mutations every 20 minutes (Anonymous 1998).chapter 3:
Brookes (1998) gives a popular account of the concepts of species and speciation. Orr and Smith (1998) explore the role of ecological divergence in the rise of reproductive isolation and speciation. Galis and Metz (1998) discuss the roles of sexual selection and niche differentiation on the explosive speciation of cichlid fishes in Lake Victoria. Geiser and others (1998) describe cryptic speciation in a fungus.
On the basis of computer simulations, Kondrashov and Shpak (1998) report that assortative mating can give rise both to reproductive isolation and to sympatric speciation. Gavrilets and others (1998) report on computer simulations that indicate the possibility of rapid speciation in subdivided populations without the need of founder effects, complete isolation, or the existence of distinct adaptive peaks. Ting and others (1998) investigate the speciation role of a rapidly evolving homeobox found in a male sterility gene in Drosophila. Swanson and Vacquier (1998) investigate gamete interactions in abalone involving egg lock/sperm key proteins that open the vitelline envelope of the egg to allow the sperm to enter, and how these can evolve to produce reproductive isolation and new species. Waugh O'Neal and others (1998) investigate the roles of undermethylation and retroelement activation in chromosome remodeling in interspecific hybrids.chapter 4:
Once again this year, RNCSE presents a brief summary and a bibliography of recent works, organized to parallel the structure of Of Pandas and People. On each topic there is active and ongoing research in the appropriate sciences as well as a growing bibliography of resources for those interested in specific topics. By contrast, in the 11 years since the publication of the first edition of Pandas and the 6 years in which I have been preparing these summaries, the scientific triviality of the "intelligent design" theory is, and has been, manifest in the lack of any primary research reports based on "intelligent design" in the peer-reviewed scientific literature.
chapter 1:
The Origin of Life
Before investigating the possible origin of life, one ought to know what it is. The difficulties of defining "life" are reviewed by Holmes (1998). Radetsky (1998) and Joyce and Orgel (1998) summarize current ideas about the origin of life.
The Space Connection
Strong polarization of infrared light has been observed in the star-formation regions of the Orion nebula. Such polarization at short wavelengths might result in "left-handed" interstellar organic molecules that could have found their way to earth in comets, meteors, and interplanetary dust. This process would account for one of the most characteristic features of biological molecules — namely the overwhelming preference for "left-handed" over "right-handed" forms of organic compounds associated with all living things on earth (Bailey and others 1998). Recreating the environment of outer space in the lab produces many organic compounds representing some of the key ingredients of life that condense on simulated dust grains, including lipid-like molecules that can form cell-like vesicles (Schueller 1998).The Martian meteorite still engenders debate (Kerr 1998a; Gibbs 1998). Several new studies (such as Bada and others 1998) indicate that the organic material in the meteorite is the result of terrestrial contamination. Research on the possible extraterrestrial organic materials in other meteorites continues. The Murchison meteorite contains over 70 different kinds of amino acids, many uniquely extraterrestrial (Pizzarello and Cronin 1998). Brainard (1998) speculates that even though Martian microbes may exist, they may be very scarce and hard to find on Mars.
Scientists are also reporting more evidence about the materials and conditions elsewhere in our solar system that could have supported the origin of life. Highly detailed pictures of Europa's surface by the Galileo spacecraft continue to reinforce the hypothesis that a watery ocean is hidden beneath the icy surface (Holden 1998). The paucity of craters on the surface is interpreted as showing that the surface is an active young surface (Kerr 1998b). Other evidence for an ocean is the detection of absorption bands in reflectance spectra indicating hydrated salts on the surface (McCord and others 1998). Evidence for induced magnetic fields is interpreted as evidence for subsurface oceans on both Europa and Callisto (Kivelson and others 1998). Svitil (1998) discusses the possibility of large amounts of methane and other organic compounds on Saturn's moon Titan.
As to the question of whether life could have arisen on planets elsewhere in the universe, astronomers continue to find evidence for extrasolar planets (Semeniuk 1998; Cowen 1998a). Most are inferred from observed wobbles in their stars' paths. Others are inferred from irregularities in a star's dusty disk (Cowen 1998b; Kalas 1998). One has been imaged directly (Leutwyler 1998). The known extrasolar planets now outnumber the planets of the solar system.
Extremophiles
Researchers continue to find organisms in habitats previously thought to be too extreme for life to exist. Priscu and others (1998) describe the microbes existing in Antarctic lake ice. Cary and others (1998) report on tube worms living on the outer walls of deep-sea hydrothermal vents where the temperatures may be as high as 81̊C. General reviews of extremophiles are given by DeLong (1998) and Pain (1998a). Cossins (1998) reviews Michael Gross's book Life on the Edge: Amazing Creatures Thriving in Extreme Environments (1998). Pain (1998b) discusses the microorganisms that live deep in the earth's crust.Researchers also claim to have found tiny nanobacteria in rocks and in the Martian meteorite. Other workers are skeptical of the existence of these organisms (Vogel 1998). Kajander and Ciftcioglu (1998) report on finding such ultramicroorganisms in biological materials.
Prebiotic Chemistry
Research continues into the production billions of years ago of organic molecules typical of living things on earth. Cleaves and Miller (1998) have demonstrated that many organic polymers and inorganic ions dissolved in the early ocean would act as ultraviolet absorbers, protecting the organic compounds farther below the surface and thus allowing them to accumulate. Canfield (1998) proposes a new model for Proterozoic ocean chemistry in which sulphide, rather than oxygen, is responsible for removing iron from ocean waters. Although there was some oxidation at the earth's surface around 2000 million years before the present (MaBP) ago, aerobic deep-ocean waters did not develop until about 1000 MaBP. Boctor and others (1998) report that nitrogen reduction can be brought about through mineral catalysis under conditions typical of hydrothermal vents.Nitta and others (1998) report that ribosomal RNA can produce peptide bonds. Similarly, utilizing test-tube evolution, Zhang and Cech isolated a pure RNA pseudo-ribosome that could link amino acids together (Cohen 1998). Carmi and others (1998) report on "deoxyribozimes" (for example, a DNA molecule) that can act as an enzyme and cleave single-stranded DNA oligonucleotides. Unrau and Bartel (1998) report the creation, by test-tube evolution, of an RNA molecule that can synthesize a pyrimidine nucleotide from its phosphate, sugar, and base constituents.
Some theorists favor a high-temperature origin of life near oceanic hydrothermal vents (Balter 1998). Levy and Miller (1998) report that this is unlikely because the nucleotide bases are not sufficiently stable at such high temperatures. Huber and Wachtershauser (1998) claim that amino acids can be activated and condensed into peptides under conditions like those prevailing near vents. Another idea is that mineral surfaces may have aided in the production of polymers (Edwards 1998; Smith 1998; Parsons and others 1998). Along these lines, Luther and others (1998) describe a self-replicating chemical system involving solid support for the chemical templates that can increase the concentration of oligonucleotide analogues exponentially.
Poole and others (1998) describe a Darwinian model for the evolution of life from the late stages of the RNA world through to the emergence of eukaryotes and prokaryotes. In connection with this, Jeffares and others (1998) derive criteria for identifying ribozyme relics of ancient RNA structures in modern microorganisms and creating a model of the last ribo-organism before the advent of protein-directed catalysis.
The Rise of Eukaryotes
Eukaryotes are thought to have arisen from prokaryotes when archaebacteria engulfed eubacteria, which eventually became mitochondria and chloroplasts. Martin and Muller (1998) put forward the hypothesis that this process was not just an accident but the development of a symbiosis: the orginal host was a methanogen that consumed hydrogen and carbon dioxide and produced methane. The symbiont that eventually became the mitochondrion was a bacterium that made hydrogen and carbon dioxide as its waste products.A rich find of unicellular eukaryotic fossils along with bacteria have been found in 800-Ma-old rocks on Canada’s Victoria Island (Monastersky 1998b). South African researchers have found evidence that primitive unicells may have lived in soil on land 2000–2200 MaBP (Monastersky 1998a). Recent experiments suggest that multicellular colonies may evolve from unicells as a defense against predation. Unicellular predators found the colonies too big to ingest (Blackman 1998).
chapter 2:
Genetics and Evolution
Mutation
Current research demonstrates how mutations can produce variations with positive outcomes; mutation is not universally, or even generally, a bad thing. Rainey and Travisano (1998) describe the rapid evolution of an aerobic bacterium when exposed to novel environmental conditions in multiple ecological niches. Boyce (1998) reports that mutations that appear to be neutral may have subtle effects under stressful conditions. After experiencing heavy DNA damage, bacteria may increase their mutation rates by partially disabling their DNA repair systems in order to generate new genotypes that might be evolutionarily useful (Goodman 1998; Brookes 1998).Genomes exhibit many diverse phenomena and genetic information is often stored in complex ways. A gene, for example, may be split into exons and introns, the latter being excised as "junk" when the gene is transcribed into messenger RNA. Similarly, some proteins that are produced by ribosomes consists of exteins and inteins, the latter being excised from the polypeptide chain to make the final form of the protein. Wu and others (1998) describe such a protein and its gene in the microbe Synechocystis. An added complication is that the gene itself is split into 2 parts found in 2 different parts of the chromosome. Each part codes for an extein and part of the one intein. Only after the 2 polypeptides are formed do they join to form the complete intein, which then excises itself to form the final protein molecule!
Pennisi (1998b) reviews the ways in which genomes can change, including transposable elements, shuffling or duplication of material, mutational hotspots, and inaccurate copying of 2- and 3- base repeats which may affect the function of neighboring genes. Max (1998) discusses pseudogenes, short and long interspersed elements, retroviruses, and retroposons as evidence for evolution. The numbers of multiple elements are still increasing in mouse species (Anonymous 1998); the house mouse has 3000 of them! Vogel (1998) and Pennisi (1998a) review modern ideas and experiments concerning the evolution of the genetic code. Van den Burg and others (1998) were able to utilize mutations to modify a bacterial enzyme to work at very high temperatures.
Natural Selection
Sargent and others (1998) review the phenomenon of industrial melanism. Losos and others (1998) explore the role of historical contingency in influencing adaptive radiation of Anolis on different islands in the Caribbean. A special section of Science (Hines and Culotta 1998) contains a number of papers reviewing hypotheses about the evolution of sex, including the possible adaptive value of sex (Barton and Charlesworth 1998) and tests of the various hypotheses (Wuethrich 1998).A number of papers dealt with sexual selection. Arnqvist (1998) discusses the possibility that the shape of male genitalia evolved under sexual selection. Evans (1998) tests the hypothesis that sexual selection produced the long tail streamers of male swallows, discovering that the length of the tail is governed by natural selection. Call duration in tree frogs may be used by females to select males with superior genetic quality (Welch and others 1998). In swordtail fish, females prefer larger swords (Rosenthal and Evans 1998). In stalk-eyed flies, females prefer males that have longer stalks (Wilkinson and others 1998). The long eye stalk condition is linked to the possession of a Y chromosome that suppresses the meiotic drive of a "selfish" X chromosome that biases the sex ratio in favor of females.
Designing with Evolution
Petit (1998) gives a popular description of the use in industry of genetic algorithms to design engineering systems, directed (test-tube) evolution to produce new drugs, and genetic programming to evolve computer programs. Taubes (1998) discusses research on FPGA (Field Programmable Gate Array) chips, which allow computer hardware to be programmed by genetic algorithms. Lenski (1998) provides an informative book review on artificial life’s existing and evolving in computers.Landweber and others (1998) review the successes in ribozyme engineering using test-tube evolution. They list 2 dozen new ribozymes "evolved" either from some precursor RNA or from random sequences of RNA. Macbeath and others (1998) used test-tube evolution to redesign enzyme topology. Crameri and others (1998) describe DNA shuffling, a technique used to speed up test-tube evolution.
Genomes
The genomes of more organisms continue to be sequenced. In 1998, the genomes of 5 microorganisms and 1 multicellular animal were sequenced. These include the hyperthermophilic bacterium Aquifex aeolicus with about 1.5 million base pairs (Mbp; Deckert and others 1998), the tuberculosis microbe Mycobacterium tuberculosis with about 4.4 Mbp and 4000 genes (Cole and others 1998), the syphilis spirochete Treponemas pallidum with about 1.3 Mbp and 1041 genes (Fraser and others 1998), the intracellular human pathogen Chlamydia trachomatis with about 1 Mbp (Stephens and others 1998), the typhus microbe Rickettsia prowazekii with about 1.1 Mbp and 834 genes, many of which are similar to mitochondrial genes (Andersson and others 1998), and the first animal to have its genome completely sequenced, the nematode worm Caenorhabditis elegans with 97 Mbp and 19 000 genes (Hodgkin and others 1998; Hodgkin and Herman 1998). The Drosophila genome sequence will be finished soon. Work continues on sequencing the plant model Arabidopsis (the European Union [EU] Arabidopsis Genome Project 1998; Meinke and others 1998). Huynen and Bork (1998) report on a comparative study of 9 microbial genomes.It is estimated that vertebrates have between 50 000 and 100 000 genes, while invertebrates have fewer than 25 000. Simmen and others (1998) estimate that the invertebrate chordate Ciona has about 15 000 genes. Evidence indicates that at least 2 rounds of polyploidy occurred in the vertebrate ancestors after the separation of Amphioxus and the craniates (Pebusque and others 1998; Postlethwait and others 1998).
The extensive data on microbial sequences point to the possibility that early in the evolution of life, before the 3 domains (Bacteria, Eukara, and Archaea) emerged, there was much horizontal transfer of genetic material (Pennisi 1998; Koga and others 1998; Woese 1998; Katz 1998). Miller (1998) discusses horizontal gene transfer occurring today, since it could allow genetically engineered microbes to pass their genes to other species in the environment with unintended results. Katz (1998) reviews the latest ideas on the evolution of eukaryotes. She presents evidence that the eukaryote archezoans, which do not possess mitochondria, have secondarily lost those organelles. Aravalli and others (1998) report that Archaea, originally considered to be confined to extreme environments, are much more widespread, being found in soils, lake sediments, marine picoplankton and deep-sea locations. Microbiologists have estimated that there are 5 x 1024 bacteria living on earth in the ocean, in the soil, beneath the surface, in the air, and inside animals. Soil and subsurface habitats account for 94%; the insides of animals account for only a fraction of 1 percent. In the oceans, any given bacterial gene is estimated to undergo an average of 4 mutations every 20 minutes (Anonymous 1998).
chapter 3:
The Origin of Species
Brookes (1998) gives a popular account of the concepts of species and speciation. Orr and Smith (1998) explore the role of ecological divergence in the rise of reproductive isolation and speciation. Galis and Metz (1998) discuss the roles of sexual selection and niche differentiation on the explosive speciation of cichlid fishes in Lake Victoria. Geiser and others (1998) describe cryptic speciation in a fungus.
On the basis of computer simulations, Kondrashov and Shpak (1998) report that assortative mating can give rise both to reproductive isolation and to sympatric speciation. Gavrilets and others (1998) report on computer simulations that indicate the possibility of rapid speciation in subdivided populations without the need of founder effects, complete isolation, or the existence of distinct adaptive peaks. Ting and others (1998) investigate the speciation role of a rapidly evolving homeobox found in a male sterility gene in Drosophila. Swanson and Vacquier (1998) investigate gamete interactions in abalone involving egg lock/sperm key proteins that open the vitelline envelope of the egg to allow the sperm to enter, and how these can evolve to produce reproductive isolation and new species. Waugh O'Neal and others (1998) investigate the roles of undermethylation and retroelement activation in chromosome remodeling in interspecific hybrids.
chapter 4:
The Fossil Record
The Cambrian Explosion
Evidence is accumulating that complex animals evolved long before they appeared as fossils in the "Cambrian explosion". Seilacher and others (1998) report the finding of worm burrows in 1000-Ma-old Precambrian rocks, but there is much controversy over the dating of the rocks and the interpretation of the fossils. Xiao and others (1998; see also Gould 1998) have discovered almost perfectly preserved fossils of algae and animal embryos in 570-Ma-old phosphorites in southern China — 20 Ma before the Cambrian Period. Molecular dating techniques also indicate a much earlier evolution of metazoans (about 680–830 MaBP) in the Precambrian (Gu 1998; Bromham and others 1998). Thomas (1998) reconsiders the Cambrian Explosion in light of these new findings. Cooper and Fortey (1998) review the evidence for metazoan evolution prior to the Cambrian fossil record.
Li and others (1998) report the finding of Precambrian sponges. Moldowan and Talyzina (1998) report biogeochemical evidence for dinoflagellate ancestors in the early Cambrian. Jensen and others (1998) report on the occurrence of Cambrian ediacarans (vendobionts). McMenamin (1998) reports on a new interpretation of ediacarans as a separate "metacellular" kingdom. Morris and Gould (1998) debate the interpretation of the Burgess Shale fauna. Morris (1998) claims that this fauna can be classified into existing phyla. Orr and others (1998) discuss the conditions under which the Burgess Shale animals were preserved. Hecht (1998) discusses the possibility (reported last year) that during Cambrian times, the earth's crust slipped around the core almost 90 degrees. The changing climatic conditions may have spurred rapid evolution. On the other hand, geologists report evidence of long geologically stable periods in the Precambrian (Anonymous 1998). The late Precambrian provides evidence for glaciation in what are now tropical latitudes. Hoffman and others (1998) explain this by a "snowball" earth hypothesis, while Williams and others (1998) prefer to invoke a change in the orientation of the earth's spin axis.
Mass Extinctions
The end-Cretaceous Chicxulub impact event is discussed by Johnson (1998), Cerveny (1998), and Pope and others (1998). Jablow (1998) describes the discovery of the Chicxulub structure. Kyte (1998) reports on the finding of a possible fragment of the asteroid in the sediments of the northern Pacific ocean. Shukolyukov and Lugmair (1998) present geochemical evidence that the asteroid had a carbonaceous chondrite composition. Evidence has been reported (Anonymous 1998a) that the impact fractured the edge of the continent, resulting in gigantic submarine landslides and giant tsunamis.
Cowen (1998) describes the possible causes of a comet shower that may have done in the dinosaurs. Smith and Jeffery (1998) discuss the selectivity of sea-urchin extinction due to this event. Jablonski (1998) discusses the molluscan recovery. Research on plankton extinctions that occurred before the event and of plankton that survived the event is discussed in (Anonymous 1998b). Erwin (1998) discusses recoveries from mass extinctions in general. Spray and others (1998) report evidence of a late Triassic multiple impact event. Bowring and others (1998) report geochronological evidence that the End-Permian extinction event lasted less than 1 million years. Ward (1998) reports evidence that the End-Permian land animals suffered from intense global warming. Schultz and others (1998) report a Pliocene impact event in Argentina. Wynn and Shoemaker (1998) describe an impact in Arabia that occurred in historic times. Gibbs (1998) describes the search for an impact crater in Greenland that formed in December 1997.
New Fossils
New fossil finds include Devonian myriapods from Australia (Edgecombe 1998) and ants in amber from New Jersey 92 MaBP (Agosti and others 1998). Plant fossils include complex rooted plants from the early Devonian 390 MaBP (Jensen 1998), a Jurassic angiosperm (Sun and others 1998), and an upper Cretaceous monocot (Gandolfo and others 1998). The discovery of Late Jurassic pollinating Brachyceran flies (Ren 1998) supports the Jurassic origin of angiosperms. New fish fossils include a lobe-finned fish with "fingers" (Daeschler and Shubin 1998) and a complete primitive rhizodont lobe-finned fish from Australia (Johanson and Ahlberg 1998). New dinosaur fossils include an early Carboniferous tetrapod (Clack 1998), a fish-eating dinosaur from Africa (Sereno and others 1998), sauropod dinosaur eggs and embryos from the upper Cretaceous of Patagonia (Coria and others 1998), a 16-inch–long claw resembling that of Velociraptor from Patagonia (Menon 1998), an early Cretaceous sea turtle (Hirayama 1998), a new species of predatory dinosaur from Madagascar (Sampson and others 1998), a giant Cretaceous dinosaur coprolite (Chin and others 1998), a Jurassic ankylosaur dinosaur (Carpenter and others 1998), and a small theropod dinosaur fossil from Italy with soft tissue preservation (Sasso and Signore 1998). Other new vertebrate fossils include a new Eocene archaeocete whale from India (Bajpai and Gingerich 1998), new specimens of giant armadillo from Florida (Anonymous 1998b), and a 53-Ma-old jaw representing the tiniest known mammal (only 1.3 grams) from Wyoming (Monastersky 1998a).
Adrain and others (1998) discuss Ordovician trilobite diversity. The osteolepiform (lobe-fin fish) ancestors of the tetrapods are discussed by Ahlberg and Johanson (1998). Clark and others (1998) report fossil evidence that early pterosaurs were quadripedal. Evidence that Cretaceous plesiosaurs ate ammonites is reported by Sato and Tanabe (1998). New primitive skeletons from Japan shed light on the origin of ichthyosaurs (Motani and others 1998). Fossils of Cretaceous duck-billed dinosaurs have been found in Antarctica (Monastersky 1998a). Late Cretaceous fossils of champsosaurs, large crocodilelike reptiles, have been found in the high Canadian Arctic (Tarduno and others 1998), suggesting that the poles had a warm climate at that time.
Traces of bone tumors are found in dinosaur vertebrae (Anonymous 1998c). Growth layers in dinosaur bones indicate that large sauropods grew fast and attained their full size in about 10 years (Stokstad 1998). Some Cretaceous sail-backed dinosaurs may have actually been humpbacked (Anonymous 1998a). Studies of the bone growth of high-latitude Australian dinosaur fossils revealed no growth lines, indicating that they might have been endothermic and grown continuously (Monastersky 1998b).
New, more complete specimens of the Late Cretaceous mammal Deltatheridium (Rougier and others 1998) shed light on the evolutionary relations of basal marsupials and early mammals. Flynn and Wyss (1998) review recent knowledge of South American mammal fossils. Meng and McKenna (1998) discuss mammalian faunal turnovers in the early Tertiary. Shoshani (1998) reviews elephant evolution. DNA analysis of the excrement of the extinct ground sloth reveals the plant species in its diet (Poinar and others 1998). Zimmer (1998c) recalls the 19th-century discovery of the early whale Basilosaurus. A new fossil of a mouse-sized flightless animal, Phenocolemur, suggests that the ancestors of bats hung from tree branches by all four legs (Hecht 1998). Zimmer (1998a) discusses bats and their evolution.
Grande (1998) describes the fossil-rich Eocene lake deposits of Wyoming. Zimmer (1998b) gives an in-depth review of the evolution of amphibians from fishes and the evolution of whales from land mammals. Lockley (1998) reviews the data on fossil footprints. Such fossil tracks, found all over the world, are one of the most direct lines of evidence indicating that the geologic strata were not laid down continuously by a giant world-wide flood. Erdmann and others (1998) report on the finding of modern coelacanth populations (Latimeria) off the coast of Indonesia.
Birds
Britt and others (1998) have discovered passageways for air sacs in Archaeopteryx specimens, demonstrating that the hollow postcranial bones were pneumatized and reinforcing the idea that they are homologous with similar pneumatized bones in the skeletons of non-avian theropod dinosaurs. Controversy over the dinosaurian origin of birds continues: Padian and Chiappe (1998), Thomas and Garner (1998), and Martin (1998), Ostrom (1998), and Padian (1998) summarize the opposing views; Hicks and others (1998) debate Rubin's 1997 claim that the theropod lung could not have evolved into a bird lung. Questions over whether the 3 digits in a bird's wing are homologous to the 3 digits in a theropod’s arm are discussed in (Anonymous 1998).
A theropod that might have had a feathered crest (Chen and others 1998) and 2 feathered dinosaurs (Ji and others 1998) have been found in the Lower Cretaceous formations in China. Ackerman (1998) summarizes the discovery of these animals in an article with many beautiful illustrations. The early Cretaceous Chinese fossil site yielding these discoveries is described by Wang (1998); Chiappe (1998) describes the Spanish site yielding early Cretaceous birds. The skull of a Late Cretaceous relative of Mononykus has been found in Mongolia (Chiappe and others 1998). The oldest Coelurosaurian theropod (from the Early Jurassic) is reported from China (Zhao and Xu 1998). Forster and others (1998) report on a primitive Late Cretaceous bird with a large sicklelike claw similar to those of dromaeosaurid dinosaurs. Stidham (1998) reports on a Late Cretaceous parrot fossil. Bones of a large (possibly 140 kg) flightless bird of the Late Cretaceous, Gargantuavis, have been found in France. This species may have produced the hundreds of fossil eggs found in the region previously thought to be dinosaur eggs (Holden 1998). Two more books on the origin of birds appeared this year (Dingus and Rowe 1998; Shipman 1998).
Miscellaneous
Babcock (1998) gives a good introduction to the literature on taphonomy, the science of what happens after an animal dies and under what conditions it will fossilize. Hazard (1998) offers suggestions how to teach about transitional forms.
Human Evolution
Two 45-Ma-old primate fossils found in Southeastern China are the smallest known, being less than 1 cm tall (Anonymous 1998a). They may represent the most primitive anthropoids. Gibbons (1998b) suggested that one ape line that returned to Africa from Asia may be the ancestor of the modern apes. New evidence suggests that the Miocene ape Oreopithecus was bipedal (Anonymous 1998b). A recent anatomical study has revealed that the chimpanzee brain exhibits asymmetry similar to that of the human brain in an area associated with language (Bower 1998a).
Several previous finds have been re-evaluated. The purported Neandertal bone flute appears to have been gnawed and punctured by an animal, perhaps a wolf (Bower 1998b). Rock art in Australia previously dated at 50–75 000 years ago has been redated to about 10,000 years by different dating methods (Bird and others 1998).
McKinney (1998) re-evaluates the "neotenic ape" model of the origin of humans. The 117,000–year-old footprints of anatomically modern humans found in 1995 near Langebaan Lagoon in South Africa will be moved to the safety of a museum (MacKenzie 1998). They are no longer the oldest known such footprints. Another set, the Nahoon prints, which have been in a South African museum for the past 34 years, have been dated at 200,000 years (Holden 1998a). Agnew and Demas (1998) discuss the preservation of the Laetoli footprints. The discovery of a complete Australopithecine skull and limb bone material in the Sterkfontein caves of South Africa was announced in December (Gee 1998). Computer simulation of Lucy's legs indicate that she walked in a human manner, not with a chimp-like gait (Lincoln 1998).
Computer imaging techniques have measured the endocranial capacity of a South African Australopithecus africanus specimen at about 515 cc — smaller than previous estimates. The endocranial capacities of other early hominids may also be too large (Conroy and others 1998). New specimens of Australopithecus anamensis confirm its age as intermediate between the older Ardipithecus ramidus and the younger Australopithecus afarensis (Leakey and others 1998). Recent reports suggest that A africanus has more apelike body proportions than A afarensis (Svitil 1999). A 1-Ma-old skull with a mixture of H erectus and H sapiens characters has been found in Eritrea (Albianelli and others 1998). A skeleton of a modern human child has been found in the Nile valley dating from a time (55 000 years) when many anthropologists think modern humans were about to invade Europe and Asia (Copley 1998).
Fission-track dating of stone tools and fossils on the island of Flores date at 900 000 years ago, suggesting that Homo erectus was capable of crossing open water in some kind of watercraft (Morwood and others 1998). Stone tools found in Israel's Hayonim cave have been dated at 200 000 years ago. Similar tools found at 2 other sites date to 250 000 years ago (Bower 1998c). Reexamination of the evidence for fire at Zhoukoudian, China, does not reveal any direct evidence for in situ burning (Weiner and others 1998).
Recent discoveries have led anthropologists to conclude that the New World was invaded by humans long before 11 000 years ago (McDonald 1998). The first humans may have reached the New World 30 000 years ago. They may have included people of European ancestry (Lewin 1998a). Last year's analysis of Neandertal DNA indicated that they were not directly ancestral to modern Homo sapiens, but some anthropologists, such as Milford Wolpoff, question that conclusion (see Holden 1998b and related readings). The replacement of Neandertals by modern Cro-Magnons is discussed by Mellars (1998). The June 1998 issue of Current Anthropology (vol 39, supplement) has several articles on Neandertals and early modern humans (Brainard 1998).
The anatomical requirements for language are discussed by Cartmill (1998). Investigations on the size of the hypoglossal canal, which transmits the nerves of the tongue, have led some authorities to conclude that Neandertals could talk as well as modern humans do (Kay and others 1998). According to Lieberman (1998), the origin of the cranial features characteristic of modern humans are related to reduction of the sphenoid bone. That ancient humans practiced cannibalism has been controversial. New evidence indicates that it occurred in the prehistoric American southwest and among the Aztecs, Maoris, and people in England 12 000 years ago (McKie 1998).
Analysis of human Y chromosomes supports the "out-of-Africa" hypothesis but also indicates that subsequently some populations returned to Africa (Hammer and others 1998). Patterns of mitochondrial genes and the non-recombining part of the Y chromosome suggest that humans had a small effective population size (about 10 000) during the Pleistocene (Harpending and others 1998). This same evidence rules out the multiregional hypothesis. Similar results come from studies of variation in the human dystrophin gene (Zietkiewicz and others 1998). This bottleneck may have been caused by climate changes caused by the eruption of Mount Toba in Sumatra about 71 000 years ago. This eruption was about 4000 more severe than the recent Mount St Helens eruption (Anonymous 1998c).
Although the apparent continuity of fossil and modern anatomy in China appears to support the multiregional hypothesis, a recent genetic study of Chinese populations (Chu and others 1998) does not. Rather, it indicates that the ancestors of East Asia entered from Southeast Asia. Comparison of mtDNA and Y chromosome data seems to indicate that women had a migration rate 8 times that of men (Boyce 1998).
With the Human Genome Project in full swing, some researchers are beginning to look for the genes that distinguish us from apes. One such difference, in the human CMP-sialic acid hydroxylase enzyme (Gibbons 1998a), involves a 92–base-pair deletion, which also causes a frame shift. This finding has relevance for the argument of anti-evolutionists that although humans and apes differ in only 1% of their genome, this amounts to 1 million base pairs and hence 1 million favorable point mutations would have had to occur (Schroeder 1997: 120) Obviously, point mutations are not the only way in which 1 million base-pair differences could have occurred.
Problems with calibrating mtDNA mutation rates are reviewed by Gibbons (1998b). Recent forensic work (such as identifying the recently discovered bodies of Tsar Nicholas and his family) has discovered many cases of heteroplasmy — instances where an individual has more than one mtDNA sequence. More than one type of mitochondrion can be inherited from a person's mother because the egg contains hundreds of these bodies. Such differences arose by mutation, and their occurrence suggests much higher mutation rates than previously thought.
A special section on archaeology in the November 20, 1998, issue of Science (Appenzeller and others 1998) reviews the latest ideas and information on the origin of art (Appenzeller 1998), the development of communities (Balter 1998), the birth of agriculture (Pringle 1998), and the origin of language (Holden 1998c). Lewin's human evolution textbook (Lewin 1998b) provides an up-to-date exposition of all aspects of human evolution.
chapter 5:
Homology
Richardson and others (1997) published a paper that compared many vertebrate embryos to investigate the validity of the phylotype concept and, as an aside, claimed that Haeckel's figures illustrating recapitulation were inaccurate to the point of being fraudulent — a point not overlooked by anti-evolutionists. This paper produced a series of letters in Science in 1998 (Hanken and Richardson 1998; Richardson and others 1998). The authors of the original paper say that Haeckel was essentially correct: his drawings enhanced superficial similarities — mainly of the general outlines of the various embryos — but certainly did not concoct the similarities of pharyngeal slits, and so on, that were, in fact, known to all other 19th-century anatomists, including Haeckel's enemies. (The few illustrations of recapitulation that Darwin used in The Descent of Man were taken from other sources). The "fraud" has been fully exploited by anti-evolutionists in their attempts to discredit evolution (Behe and others 1998).
Gilbert (1998) summarizes recent conceptual breakthroughs in developmental biology. These include the ideas that genetic and biological mechanisms can indeed explain development, that the core of development involves various signal transduction mechanisms, that homologous genes and pathways exist among distantly related phyla, and that modularity in development and developmental changes can result in major evolutionary changes. Modern findings on signaling molecules in development are summarized by Strauss (1998). Transmembrane receptors including olfactory receptors may function as a cell surface code for assembling embryos (Dreyer 1998).
A number of papers document new homeobox genes and their role in macroevolution. Wray and Raff (1998) report that echinoderms use the same regulatory genes as other animals to make both their bilateral larvae and their radial adults. The expression pattern of AmphiEn, which initiates certain repeated body segments in vertebrates, is similar to that of engrailed in invertebrates. Hox genes in ribbonworms (Nemerteans) consist of 1 cluster of 6 genes (Kmita-Cunisse and others 1998), and their most closely related orthologs are found in the mouse or Amphioxus. This finding indicates that ribbonworms have diverged relatively little from the last common ancestor of protostomes and deuterostomes.
Martinez and others (1998) report that coelenterates do not possess a full complement of Hox genes. A new cluster of 3 Hox-like genes (the ParaHox cluster) has been found in Amphioxus (Brooke and others 1998). Henry (1998) reports on a Hox gene needed for endoderm development.
The general role of homeobox genes in evolution and the Cambrian explosion is discussed in a number of papers (Cameron and others 1998; Pendick 1998; Meyer 1998). The discovery of 7 Hox clusters in modern fish (tetrapods have only 4) may account for the wide diversity displayed by modern fishes (Amores and others 1998). Hox genes and their role in vertebrate hindbrain segmentation are discussed by Prince (1998). Holland and Holland (1998) report on the expression patterns of 5 Hox genes in Amphioxus, which indicate the presence of a forebrain.
Martindale and Henry (1998) discuss the evolution of bilaterality. Several papers summarize our knowledge of limb development (Gardiner and others 1998; Schwabe and others 1998). The wide variability in tetrapod limb morphology is probably due to the timing and sequence of expression of Hox genes. Duboule and Wilkins (1998) point out that most of our genes are shared with other organisms, so phylogenetic diversity depends not on evolution of new genes, but on differential use of the same component genes. Evolutionary "bricolage" (that is, tinkering) with the developmental system is very conservative.
Tautz (1998) and Lee (1998) explore the use of the concept of homology in comparative and evolutionary studies. Modern techniques for reconstructing evolutionary trees are summarized by Lewin (1998). Hall (1998) presents a review of historical and recent research bearing on the germ-layer theory.
chapter 6:
Biochemical Similarities
Molecular taxonomy is changing our conception of the relationships of the animal phyla. Maley and Marshall (1998) provide a brief summary of molecular systematics and some of the outstanding issues in the field. Collins (1998) compares hypotheses concerning the evolution of the Bilateria based on ribosomal RNA data. Bilaterians seem to be closely related to placozoans and cnidarians. Balavoine and Adoutte (1998) review the evidence from ribosomal RNA data for grouping the triploblastic phyla into 3 large groups; Anderson and others (1998) report Hox gene data that may indicate that the protozoan Myzozoa may be a degenerate metazoan.
Several molecular studies appear to conflict with morphological and paleontological data. Sequencing of the mitochondrial genome suggests that turtles may be more closely related to diapsid than to anapsid reptiles (Zardoya and Meyer 1998). Another mitochondrial genome study suggests a closer-than-expected relationship between hippopotamus and whale clades (Ursing and Arnason 1998), but these findings are not consistent with other studies. The most newly discovered ancient whale fossils weaken the link to mesonychids and make the artiodactyl connection more plausible (Normile 1998). A molecular time scale for vertebrate evolution (Kumar and Hedges 1998) indicates that many modern mammalian orders diverged in the Cretaceous rather than the Tertiary, yet the latest fossil evidence (Normile 1998) disputes this hypothesis. Gaut (1998) reviews the research done on molecular clocks using plant data.
Study of mitochondrial introns suggests the liverworts were the earliest land plants (Qiu and others 1998). De Ley and others (1998) use ribosomal DNA data to classify the nematodes. Springer and others (1998) use both mitochondrial and nuclear gene data to resolve ambiguities in the relationships of the marsupials. The studies have confirmed that the marsupials are a natural grouping. Schubart and others (1998) studied the mitochondrial genes of Jamaican land crabs and concluded that they are descended from one marine ancestor about 4 MaBP.
Summary
Astronomers continue to find evidence of extrasolar planetary systems. More genomes are being completely sequenced, including the first genome to be sequenced of an animal, the nematode Caenorhabditis elegans, which has about 19, 000 genes. Darwinian evolutionary paradigms, in the form of genetic algorithms and test-tube evolution, are being used more and more to design engineering systems and to produce new enzymes, many of medical importance. Traces of animals that preceded the Cambrian explosion have been found, as have been feathered dinosaurs. New human fossils are being found that add variety and depth to the human family tree. The discovery of new homeobox-type genes are helping to elucidate developmental systems.
All these new findings are supportive of evolution and advance our knowledge of the history and variety of life beyond what we knew in 1989 when Of Pandas and People was first published. By contrast, the "intelligent design" theory presented in the pages of Pandas has yet to produce any scientific advances in the main areas of study laid out in the 6 chapters of the original (and revised) textbook.
Homology
Biochemical Similarities
References
Chapter 1: The Origin of Life
General
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The Space Connection
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Kerr RA. Planetary scientists sample ice, fire, and dust in Houston. Science 1998b Apr 3; 280: 38–9.
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Leutwyler K. New planet? Scientific American 1998 Aug; 279 (2): 22. Related reading: [Anonymous]. Planet poseur? Discovery 1998 Aug; 19 (8): 24.
McCord TB, Hansen GB, Fanale FP, Carlson RW, Matson DL, Johnson TV, Smythe WD, Crowley JK, Martin PD, Ocampo A, Hibbitts CA, Granahan JC, and the NIMS Team. Salts on Europa's surface detected by Galileo's near infrared mapping spectrometer. Science 1998 May 22; 280: 1242–5. Related reading: [Anonymous]. Salty moon. New Scientist 1998 Mar 28; 157 (2127): 23. Cowen R. Europa's salty surface. Science News 1998 Jan 3; 153 (1): 11. Kargel JS. The salt of Europa. Science 1998 May 22; 280: 1211–2.
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Semeniuk I. Real worlds of other suns. SkyNews 1998 Nov/Dec; 4 (4): 12–5. Svitil KA. Hot times on Titan. Discover 1998 Mar; 19 (3): 29.
Extremophiles
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Gross M. Life on the Edge: Amazing Creatures Thriving in Extreme Environments. New York: Plenum Press 1998.
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Pain S. The intraterrestrials. New Scientist 1998b Mar 7; 157 (2124): 28–32.
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Vogel G. Finding life's limits. Science 1998 Nov 20; 282: 1399.
Prebiotic Chemistry
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Carmi N, Balkhi SR, Breaker RR. Cleaving DNA with DNA. Proceedings of the National Academy of Sciences 1998 Mar 3; 95 (5): 2233–7. Related reading: Wu C. DNA scissors cleave their comrades. Science News 1998 Apr 4; 153 (14): 223.
Cleaves HJ, Miller SL. Oceanic protection of prebiotic organic compounds from UV radiation. Proceedings of the National Academy of Sciences 1998 Jun 23; 95 (13): 7260–3. Related reading: Brainard J. What was life's first sunblock? Science News 1998 Jul 11; 154 (2): 31.
Cohen P. Molecules of ancient life are born again. New Scientist 1998 Oct 17; 160 (2156): 10. Related reading: Zhang B, Cech TR. Peptide bond formation by in vitro selected ribozymes. Nature 1997 Nov 6; 390: 96–100.
Edwards MR. From a soup or a seed? Pyritic metabolic complexes in the origin of life. Trends in Ecology and Evolution 1998 May; 13 (5): 178–81.
Huber C, Wachtershauser G. Peptides by activation of amino acids with CO on (Ni,Fe)S surfaces: Implications for the origin of life. Science 1998 Jul 31; 281: 670–2. Related reading: Vogel G. A sulfurous start for protein synthesis? Science 1998 July 31; 281: 627–9.
Jeffares DC, Poole AM, Penny D. Relics from the RNA world. Journal of Molecular Evolution 1998 Jan; 46: 18–36.
Levy M, Miller SL. The stability of the RNA bases: Implications for the origin of life. Proceedings of the National Academy of Sciences 1998 Jul 7; 95 (14): 7933–8. Related reading: Knight J. Cold start. New Scientist 1998 Jul 11; 159 (2142): 10.
Luther A, Brandsch R, von Kiedrowski G. Surface-promoted replication and exponential amplification of DNA analogues. Nature 1998 Nov 19; 396: 245–8. Related reading: Day M. Did stones nurture the first life on Earth? New Scientist 1998 Nov 21; 160 (2161): 6.
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Parsons I, Lee MR, Smith JV. Biochemical evolution II: Origin of life in tubular microstructures on weathered feldspar surfaces. Proceedings of the National Academy of Sciences 1998 Dec 22; 95 (26): 15173–6.
Poole AM, Jeffares DC, Penny D. The path from the RNA world. Journal of Molecular Evolution 1998 Jan; 46: 1–17.
Smith JV. Biochemical evolution. I. Polymerization on internal, organophilic silica surfaces of dealuminated zeolites and feldspars. Proceedings of the National Academy of Sciences 1998 Mar 31; 95 (7): 3370–5.
Unrau PJ, Bartel DP. RNA-catalysed nucleotide synthesis. Nature 1998 Sep 17; 395: 260–3. Related reading: [Anonymous]. Dawn of life. New Scientist 1998 Sep 19; 159 (2152): 27. Robertson MP, Ellington AD. How to make a nucleotide. Nature 1998 Sep 17; 395: 223–5.
The Rise of Eukaryotes
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Monastersky R. Arctic fossils record evolutionary burst. Science News 1998b Nov 7; 154 (19): 294.
Chapter 2: Genetics and Evolution
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Boyce N. Good for nothing. New Scientist 1998 Jan 17; 157 (2117): 7.
Brookes M. Day of the mutators. New Scientist 1998 Feb 14; 157 (2121): 38–42.
Goodman MFJ. Purposeful mutations. Nature 1998 Sep 17; 395: 221–3.
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Pennisi E. The first codon and its descendents. Science 1998a Jul 17; 281: 330.
Pennisi E. How the genome readies itself for evolution. Science 1998b Aug 21; 281: 1131–4.
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Vogel G. Tracking the history of the genetic code. Science 1998 Jul 17; 281: 329–31.
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Natural Selection
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Rosenthal GG, Evans CS. Female preference for swords in Xiphophorus helleri reflects a bias for large apparent size. Proceedings of the National Academy of Sciences 1998 Apr 14; 95 (8): 4431–6.
Sargent TD, Millar CD, Lambert DM. The "classical" explanation of industrial melanism: Assessing the evidence. Evolutionary Biology 1998; 30: 299–322.
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Designing with Evolution
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Genomes
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[Anonymous]. Whole lotta bugs. Discover 1998 Dec; 19 (12): 28.
Aravalli RN, She Q, Garrett RA. Archaea and the new age of microorganisms. Trends in Ecology and Evolution. 1998 May; 13 (5): 190–4.
Cole ST, Brosch R, Parkhill J, Garnier T, Churcher C, Harris D, Gordon SV, Eiglmeier K, Gas S, Barry CE, Tekaia F, Badcock K, Basham D, Brown D, Chillingworth T, R Connor R, Davies R, Devlin K, Feltwell T, Gentles S, Hamlin N, Holroyd S, Hornsby T, Jagels K, Krogh A, McLean J, Moule S, Murphy L, Oliver K, Osborne J, Quai MA, Rajandream M-A, Rogers J, Rutter S, Seeger K, Skelton J, Squares R, Squares S, Sulston JE, Taylor K, Whitehead S, Barrell BG. Deciphering the biology of Mycobacterium tuberculosis from the complete genome sequence. Nature 1998 Jun 11; 393: 537–3. Related reading: Young DB. Blueprint for the white plague. Nature 1998 Jun 11; 393: 515–6.
Deckert G, Warren PV; Gaasterland T; Young WG; Lenox AL; Graham DE; Overbeek R; Snead MA; Keller M; Aujay M; Feldman RA; Short JM; Olsen GJ; Huber R; Swanson RV. The complete genome of the hyperthermophilic bacterium Aquifex aeolicus. Nature 1998 Mar 26; 392: 353–8. Related reading: Doolittle RF. Microbial genomes opened up. Nature 1998 Mar 26; 392: 339–42.
The EU Arabidopsis Genome Project. Analysis of 1.9 Mb of contiguous sequence from chromosome 4 of Arabidopsis thaliana. Nature 1998 Jan 29; 391:485–8. Related reading: Ecker JR. Genes blossom from a weed. Nature 1998 Jan 29; 391: 438.
Fraser CM, Norris SJ, Weinstock JM, White O, Sutton GG, Dodson R, Gwinn M, Hickey EK, Clayton R, Ketchum KA, Sodergren E, Hardham JM, McLeod MP, Salzberg S, Peterson J, Khalak H, Richardson D, Howell JK, Chidambaram M, Utterback T, McDonald L, Artiach P, Bowman C, Cotton MD, Fujii C, Garland S, Hatch B, Horst K, Roberts K, Sandusky M, Weidman J, Smith HO, Venter JC. Complete genome sequence of Treponema pallidum, the syphilis spirochaete. Science 1998 Jul 17; 281: 375–88. Related reading: Pennisi E. Genome reveals wiles and weak points of syphilis. Science 1998 Jul 17; 281: 324–5. Seppa N. Reseachers solve syphilis genome. Science News 1998 Aug 11; 154 (5): 79.
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Koga Y, Kyuragi T, Nishihara M, Sone N. Did archaeal and bacterial cells arise independently from noncellular precursors? A hypothesis stating that the advent of membrane phospholipid with enantiomeric glycerophosphate backbones caused the separation of the two lines of descent. Journal of Molecular Biology 1998 Jan; 46 (1): 54–63. Related reading: Barnett A. The second coming. New Scientist 1998 Feb 14; 157 (2121): 19.
Meinke DW, Cherry JM, Dean C, Rounsley SD, Koornneef M. Arabidopsis thaliana: A model plant for genome analysis. Science 1998 Oct 23; 282: 662–81.
Miller RV. Bacterial gene swapping in nature. Scientific American 1998 Jan; 278 (1): 66–71.
Pebusque M-J, Coulier F, Birnbaum D, Pontarotti P. Ancient large-scale genome duplications: phylogenetic and linkage analyses shed light on chordate genome evolution. Molecular Biology and Evolution 1998; 15 (9): 1145–59. Pennisi E. Genome data shake tree of life. Science 1998 May 1; 280: 672, –4.
Postlethwait JH, Yan Y-L, Gates M, Horne S, Amores A, Brownlie A, Donovan A, Egan E, Force A, Gong Z, Goutel C, Fritz A, Kelsh R, Knapik E, Liao E, Paw B, Ransom D, Singer A, Thomson M, Abduljabbar T, Yelick P, Beier D, Joly L, Larhammar D, Rosa F, Westerfield M, Zon L, Johnson S, Talbot W. Vertebrate genome evolution and the zebrafish gene map. Nature Genetics 1998 Apr; 18: 345–9. Related reading: Aparicio S. Exploding vertebrate genomes. Nature Genetics 1998 Apr; 18: 301–3.
Simmen MW, Leitgeb S, Clark VH, Jones SJM, Bird A. Gene number in an invertebrate chordate, Ciona intestinalis. Proceedings of the National Academy of Sciences 1998 Apr 14; 95: 4437–40.
Stephens RS, Kalman S, Lammel C, Fan J, Marathe R, Aravind L, Mitchell W, Olinger L, Tatusov RL, Zhao Q, Koonin EV, Davis RW. Genome sequence of an obligate intracellular pathogen of humans: Chlamydia trachomatis. Science 1998 Oct 23; 282: 754–9. Related reading: Hatch T. Chlamydia: Old ideas crushed, new mysteries bared. Science 1998 Oct 23; 282: 638–9.
Woese C. The universal ancestor. Proceedings of the National Academy of Sciences 1998 Jun 9; 95 (12): 6854–9.
Chapter 3: The Origin of Species
Brookes M. The species enigma. New Scientist 1998 Jun 13; 158 (2138). Inside Science supplement nr. 111.
Galis F, Metz JAJ. Why are there so many cichlid species? Trends in Ecology and Evolution 1998 Jan; 13 (1): 1–2.
Gavrilets S, Li H, Vose MD. Rapid parapatric speciation on holey adaptive landscapes. Proceedings of the Royal Society of London Series B 1998; 265: 1483–9.
Geiser DM, Pitt JI, Taylor JW. Cryptic speciation and recombination in the aflatoxin-producing fungus Aspergillus flavus. Proceedings of the National Academy of Sciences 1998 Jan 3; 95: 388–93.
Kondrashov AS, Shpak M. On the origin of species by means of assortative mating. Proceedings of the Royal Society of London Series B 1998 Dec 7; 265 (1412): 2273–8.
Orr MR, Smith TB. Ecology and speciation. Trends in Ecology and Evolution. 1998 Dec; 13 (12): 502–6.
Swanson WJ, Vacquier VD. Concerted evolution in an egg receptor for a rapidly evolving abalone sperm protein. Science 1998 Jul 31; 281: 710–2. Related reading: Cohen P. Promiscuity helps the abalone evolve into a new species. New Scientist 1998 Aug 8; 159 (2146): 19.
Ting C-T, Tsaur S-C, Wu M-L, Wu C-I. A rapidly evolving homeobox at the site of a hybrid sterility gene. Science 1998 Nov 20; 282; 1501–4. Related reading: Cohen P. Splitting heirs. New Scientist 1998 Nov 28; 160 (2162): 11.Nei M, Zhang J. Molecular origin of species. Science 1998 Nov 20; 282: 1428–9.
Waugh O'Neill RJ, O'Neill MJ, and Marshall Graves JA. Undermethylation associated with retroelement activation and chromosome remodelling in an interspecific mammalian hybrid. Nature 1998 May 7; 393: 68–72.
Chapter 4: The Fossil Record
The Cambrian Explosion
[Anonymous]. A billion years of stability. Discover 1998 Sep; 19 (9): 19.
Bromham L, Rambaut A, Fortey R, Cooper A, Penny D. Testing the Cambrian explosion hypothesis by using a molecular dating technique. Proceedings of the National Academy of Sciences 1998 Oct 3; 95 (21): 12386–9.
Cooper A, Fortey R. Evolutionary explosions and the phylogenetic fuse. Trends in Ecology and Evolution 1998 Apr; 13 (4): 151–6. Related reading: Lee MSY. Similarity, parsimony and conjecture of homology: The chelonian shoulder girdle revisited. Journal of Evolutionary Biology 1998 May; 11: 379–87.
Gould SJ. On embryos and ancestors. Natural History 1998 Jul/Aug 8; 107 (6): 20–2, 58–65.
Gu X. Early metazoan divergence was about 830 million years ago. Journal of Molecular Evolution 1998 Sep; 47 (3): 369–71.
Hecht J. Tilt-a-world. Earth 1998 Jun; 7 (3): 34–7. Related reading: Kirschvink JL, Ripperdan RL, Evans DA. Evidence for a large-scale reorganization of early Cambrian continental masses by inertial interchange true polar wander. Science 1997 Jul 25; 277: 541–5.
Hoffman PF, Kaufman AJ, Halverson GP, Schrag DP. A neoproterozoic snowball earth. Science 1998 Aug 28; 281: 1342–6. Related reading: Jenkins GS, Scotese CR. An early snowball earth? [letter] Science 282 Nov 27: 1644–6. Kerr RA. Did an ancient deep freeze nearly doom life? Science 1998 Aug 28; 281: 1259–60; Monastersky R. Popsicle Planet. Science News 1998 Aug 29; 154 (9): 137–9.
Jensen S, Gehling JG, Droser ML. Ediacara-type fossils in Cambrian sediments. Nature 393: 567–9.
Li C-W, Chen J-Y, Hua T-E. Precambrian sponges with cellular structures. Science 1998 Feb 6; 279: 879–82. Related reading: Kerr RA. Pushing back the origins of animals. Science 1998 Feb 6; 279: 803–4.
McMenamin MAS. The Garden of Ediacara: Discovering the First Complex Life. New York: Columbia University Press, 1998. Related reading: Daviss B. Cast out of Eden. New Scientist 1998 May 16; 158 (2134): 26–30.
Moldowan JM, Talyzina NM. Biogeochemical evidence for dinoflagellate ancestors in the early Cambrian. Science 1998 Aug 21; 281: 1168–70.
Morris SC.
The Crucible of Creation: The Burgess Shale and the Rise of Animals. Oxford: Oxford University Press, 1998.
Morris SC, Gould SJ. Showdown on the Burgess Shale. Natural History 1998 Dec/Jan; 107 (10): 48–55.
Orr PJ, Briggs DEG, Kearns SL. Cambrian Burgess Shale animals replicated in clay minerals. Science 1998 Aug; 281: 1173–5.
Seilacher A, Bose PK, Pfluger F. Triploblastic animals more than 1 billion years ago: Trace fossil evidence from India. Science 1998 Oct 2; 282: 80–3. Related reading: Azmi RJ. Fossil Discoveries in India [letter]. Science 1998 Oct 23; 282: 627. Brasier M. From deep time to late arrivals. Nature 1998 Oct 8; 395: 547–8. Hecht J. Worms dig holes in evolutionary ideas. New Scientist 1998 Oct 10; 160 (2155): 6. Kerr RA. Track of billion-year old animals? Science 1998 Oct 2; 282: 19–21. Kerr RA. Fossils challenge age of billion-year-old animals. Science 1998 Oct 23; 282: 601. Kerr RA. Earliest animals old once more? Science 1998 Nov 6; 282: 1020. Monastersky R. Questions raised about oldest animal. Science News 1998 Oct 17; 154 (16): 255. Monastersky R. A rock that lies about its age. Science News 1998 Nov 21; 154 (21): 332. Morris SC and others. Fossil Discoveries in India: Continued [letters]. Science 1998 Nov 13; 282: 1265.
Thomas ALR. Cambrian explosion blown out of the water. Trends in Ecology and Evolution 1998 Apr; 13 (4): 129. Related reading: Budd GE, Jensen S. Trace fossils and the Cambrian explosion [letter]. Trends in Ecology and Evolution 1998 Dec; 13 (12): 507–8. Horne DJ, Thomas ALR. Cambrian explosion still in the water [letters]. Trends in Ecology and Evolution 1998 Aug; 13 (8): 322.
Williams DM, Kasting JF, Frakes LA. Low-latitude glaciation and rapid changes in the earth's obliquity explained by obliquity-oblateness feedback. Nature 1998 Dec 3; 396: 453–8. Related reading: Hecht J. Sweltering in Siberia. New Scientist 1998 Dec 5; 160 (2163): 4.
Xiao S, Zhang Y, and Knoll AH. Three-dimensional preservation of algae and animal embryos in a Neoproterozoic phosphorite. Nature 1998 Feb 5; 391: 553–8. Related reading: [Anonymous]. Interpreting late Precambrian microfossils [technical comments]. Science 1998 Dec 4; 282: 1783. Bengtson S. Animal embryos in deep time. Nature 1998 Feb 5; 391: 529–30. Svitil KA. Searching for the first animal. Discover 1999 Jan; 20 (1): 52.
Mass Extinctions
New Scientist 1998a Apr 18; 158 (2130): 23. Related reading: [Anonymous]. Surf's up, dinos are down. Discover 1998 Jul; 19 (7): 20.[Anonymous]. The long good-bye. Earth 1998b Jun; 7 (3): 16.
Bowring SA, Erwin DH, Jin YG, Martin MW, Davidek K, Wang W. U/Pb Zircon geochronology and tempo of the end-Permian mass extinction. Science 1998 May 15; 280: 1039–45. Related reading: Kerr RA. Biggest extinction looks catastrophic. Science 1998 May 15; 280: 1007. Monastersky R. Death swept earth at end of Permian. Science News 1998 May 16; 153 (20): 308.
Cerveny R. The day the dinosaurs died. Weatherwise 1998 Jul/Aug; 51 (4): 13–19.
Cowen R. Dino death: A stellar weapon ... or a high-energy flash? Science News 1998 Jan 31; 153 (5): 79.
Erwin DH. The end and the beginning: recoveries from mass extinctions. Trends in Ecology and Evolution 1998 Sep; 13 (9): 344–9.
Gibbs WW. The search for Greenland's mysterious meteor. Scientific American 1998 Nov; 279 (5): 72–9.
Jablonski D. Geographic variation in the molluscan recovery from the end-Cretaceous extinction. Science 1998 Feb 27; 279: 1327–30. Related reading: Lewin R. Survival strategy. New Scientist 1998 Mar 1; 157 (2124): 23.
Jablow V. A tale of two rocks. Smithsonian 1998 Apr; 29 (1): 32–35.
Johnson KR. Moon over Chicxulub: Will night finally fall on the dinosaur-extinction debate? American Scientist 1998 Nov/Dec; 86 (6): 568–71.
Kyte FT. A meteorite from the Cretaceous/Tertiary boundary. Nature 1998 Nov 19; 396: 237–9.
Pope KO, D'Hondt SL, Marshall CR. Meteorite impact and the mass extinction of species at the Cretaceous/Tertiary boundary. Proceedings of the National Academy of Sciences 1998 Sep 15; 95 (19): 11028–9.
Schkolyukov A, Lugmair GW. Isotopic evidence for the Cretaceous-Tertiary impactor and its type. Science 1998 Oct 30; 282: 927–9. Related reading: [Anonymous]. Bits and pieces of Armageddon. Discover 1999 Mar; 20 (3); 24. Monastersky R. Chunk of death-dealing asteroid found. Science News 1998 Nov 21; 154 (21): 324.
Schultz PH, Zarate M, Hames W, Camilion C, King J. A 3.3-Ma impact in Argentina and possible consequences. Science 1998 Dec 11; 282: 2061–3. Related reading: Kerr RA. Argentina, and perhaps its life, took a hit. Science 1998 Dec 11; 282: 1965–6.
Smith AB, Jeffrey CH. Selectivity of extinction among sea urchins at the end of the Cretaceous period. Nature 1998 Mar 5; 392: 69–71. Related reading: Marshall CR. Mass extinction probed. Nature 1998 Mar 5; 392: 17–20.
Spray JG, Kelley SP, Rowley DB. Evidence for a late Triassic multiple impact event on earth. Nature 1998 Mar 12; 393: 171–3. Related reading: [Anonymous]. Chain of craters. Discover 1998 Aug; 19 (8): 29. Kent DV. Impacts on earth in the late Triassic. Nature 1998 Sep 10; 395: 126. Melosh HJ. Craters unchained. Nature 1998 Jul 16; 394: 221–3.
Ward PD. The greenhouse extinction. Discover 1998 Aug; 19 (8): 54–8.
Wynn JC, Shoemaker EM. The day the sands caught fire. Scientific American 1998 Nov; 279 (5): 65–71.
New Fossils
Adrain JM, Fortey RA, Westrop SR. Post-Cambrian trilobite diversity and evolutionary faunas. Science 1998 June 19; 280: 1922–5. Related reading: Irion R. Parsing the trilobites' rise and fall. Science 1998 June 19; 280: 1837.
Agosti D, Grimaldi D, Carpenter JM. Oldest known ant fossils discovered. Nature 1998 Jan 29; 391: 447. Related reading: Hagmann M. Amber ants. Discover 1999 Jan; 20 (1): 52.
Ahlberg PE, Johanson Z. Osteolepiformes and the ancestry of tetrapods. Nature 1998 Oct 22; 395: 792–4. Related reading: Janvier P. Forerunner of four legs. Nature 1998 Oct 22; 395: 748–9.
[Anonymous]. Humpbacked dinosaurs. Discover 1998a Apr; 19 (4): 12.
[Anonymous]. There were giants on the earth in those days. Discover 1998b Apr; 19 (4): 14–8.
[Anonymous]. Saurian sore. Discover 1998c Oct; 19 (10): 26.
Bajpai S, Gingerich PD. A new Eocene archaeocete (Mammalia, Cetacea) from India and the time of origin of whales. Proceedings of the National Academy of Sciences 1998 Dec 22; 95 (26): 15464–8. Related reading: Monastersky R. Fossil jaw tells tale of whale evolution. Science News 1998 Oct 10; 154 (15): 229.
Carpenter K, Miles C, Cloward K. Skull of a Jurassic ankylosaur (Dinosauria). Nature 1998 Jun 25; 393: 782–3.
Chin K, Tokaryk TT, Erickson GM, Calk LC. A king-sized theropod coprolite. Nature 1998 Jun 18; 393: 680–2. Related reading: Andrews P, Fernandez-Jalvo Y. 101 uses for fossilized faeces. Nature 1998 June 18; 393: 629. [Anonymous]. Dino dung. New Scientist 1998 Jun 20; 158 (2139): 27. [Anonymous]. Ordure of Magnitude. Discover 1998 Oct; 19 (10): 32. Monastersky R. Getting the scoop from the poop of T. rex. Science News 1998 Jun 20; 153 (25): 391.
Clack JA. A new Early Carboniferous tetrapod with a melange of crown-group characters. Nature 1998 Jul 2; 394: 66–9. Related reading: Shubin N. Evolutionary cut and paste. Nature 1998 Jul 2; 394: 12–3.
Clark JM, Hopson JA, Hernandez RR, Fastovsky DE, Montellano M. Foot posture in a primitive pterosaur. Nature 1998 Feb 26; 391: 886–9. Related reading: [Anonymous]. Of pterosaur toes. Discover 1998 May; 19 (5): 11. Monastersky R. Flat-footed fossil of former flyer. Science News 1998 Mar 14; 153 (11): 172.
Coria RA, Dingus L, Jackson F, Chinsamy A, Fox M, Chiappe LM. Sauropod dinosaur embryos from the Late Cretaceous of Patagonia. Nature 1998 Nov 19; 396: 258–61. Related reading: [Anonymous]. Huevos dinosauros. Discover 1999 Feb; 20 (2): 24.
Daeschler EB, Schubin N. Fish with fingers? Nature 1998 Jan 8; 391: 133.
Edgecombe GD. Devonian terrestrial arthropods from Gondwana. Nature 1998 Jul 9; 394: 172–5. Related reading: Lincoln T. Ancient Australian arthropods. Nature 1998 Jul 9; 394: 127.
Erdmann MV, Caldwell RL, Moosa MK. Indonesian "king of the sea" discovered. Nature 1998 Sep 24; 395: 335. Related reading: Forey P. A home from home for coelacanths. Nature 1998; 395: 319–20. Glausiusz J. The old fish of the sea. Discover 1999 Jan; 20 (1): 49. Gordon AL. Coelacanth populations may go with the flow [letter]. Nature 1998 Oct 15; 395: 634. Milius S. Second group of living fossils reported. Science News 1998 Sep 26; 154 (13): 196.
Flynn JJ, Wyss AR. Recent advances in South American mammalian paleontology. Trends in Ecology and Evolution 1998 Nov; 13 (11): 449–54.
Gandolfo MA, Nixon KC, Crepet WL. Oldest known fossils of monocotyledons. Nature 1998 Aug 6; 394: 532–3.
Grande L. This land: Fossil lake. Natural History 1998 Jul/Aug; 107 (6): 66–9.
Hecht J. Branching out. New Scientist 1998 Oct 10; 160 (2155): 14.
Hirayama R. Oldest known sea turtle. Nature 1998 Apr 16; 392: 706–8. Related reading: [Anonymous]. Turtle tears. Discover 1998 Aug; 19 (8): 28. Gee H. The eyes have it. Nature 1998 Apr 16; 392: 651. Monastersky R. A sea turtle's salty tale. Science News 1998 May 30; 153 (22): 351.
Jensen M. Modern climate has roots in Early Devonian. Science News 1998 Feb 14; 153 (7): 103.
Johanson Z, Ahlberg PE. A complete primitive rhizodont from Australia. Nature 1998 Aug 6; 569–3.
Lockey MG. The vertebrate track record. Nature 1998 Dec 5; 396: 429–32.
Meng J, McKenna MC. Faunal turnovers of Palaeogene mammals from the Mongolian Plateau. Nature 1998 Jul 23; 394: 364–7. Related reading: Hartenberger J-L. An Asian grande coupure. Nature 1998 Jul 23; 394: 321. Monastersky R. Climate did in giant Mongolian mammals. Science News 1998 Aug 1; 154 (6): 95.
Menon S. King claw. Discover 1998 Apr; 19 (4): 30.
Monastersky R. Wyoming wonder: Tiniest mammal ever? Science News 1998a Oct 17; 154 (16): 255. Related reading: Leutwyler K. Mini-mammal. Scientific American 1998 Dec; 279 (6): 26.
Monastersky R. Dinosaur denizens of the dark. Science News 1998b Mar 14; 153 (11): 172. Related reading: [Anonymous]. Dinosaur bridge. New Scientist 1998 Feb 14; 157 (2121): 21.
Monastersky R. Dinosaurs kept warm in the polar chill. Science News 1998c May 30; 153 (22): 351. Related reading: Anderson I. In from the cold. New Scientist 1998 Apr 18; 158 (2130): 13.
Motani R, Minoura N, Ando T. Ichthyosaurian relationships illuminated by new primitive skeletons from Japan. Nature 1998 May 21; 393: 255–7. Related reading: [Anonymous]. Fishy mystery. New Scientist 1998 May 23; 158 (2135): 27.
Poinar HN, Hofreiter M, Spaulding WG, Martin PS, Stankiewicz BA, Bland H, Evershed RP, Possnert G, Pääbo S. Molecular coproscopy: Dung and diet of the extinct ground sloth Nothrotheriops shastensis. Science 1998 Jul 17; 281: 402–6. Related reading: Monastersky R. Paleoscatology: Prying DNA from dated dung. Science News 1998 Jul 18; 154 (3): 38. Stokstad E. A fruitful scoop for ancient DNA. Science 1998 Jul 17; 281: 319–20.
Ren D. Flower-associated Brachycera flies as fossil evidence for Jurassic angiosperm origins. Science 1998 Apr 3; 280: 85–8. Related reading: [Anonymous]. Fossil flies. Discover 1998 Aug; 19 (8): 33. Labandeira CC. How old is the flower and the fly? Science 1998 Apr 3; 280: 57–9.
Rougier GW, Wible JR, Novacek MJ. Implications of Deltatheridium specimens for early marsupial history. Nature 1998 Dec 3; 396: 459–63.
Sampson SD, Witmer LM, Forster CA, Krause DW, O'Conner PM, Dodson P, Ravoavy F. Predatory dinosaur remains from Madagascar: Implications for the Cretaceous biogeography of Gondwana. Science 1998 May 15; 280: 1048–51. Related reading: [Anonymous]. A new T. rex cousin. Discover 1998 Aug; 19 (8): 22.
Sasso CD, Signore M. Exceptional soft-tissue preservation in a theropod dinosaur from Italy. Nature 1998 Mar 26; 392: 383–7. Related reading: [Anonymous]. Bambinosaurus. Discover 1998 Jun; 19 (6): 20. [Anonymous]. A dino with guts. Earth 1998 Aug; 7 (4): 17. Leutwyler K. Dinosaur innards. Scientific American 1998 Jun; 278 (6): 20. Monastersky R. Getting to the guts of a dinosaur. Science News 1998 Apr 18; 153 (16): 252.
Sato T, Tanabe K. Cretaceous plesiosaurs ate ammonites. Nature 1998 Aug 13; 394: 629–30. Related reading: [Anonymous]. A bellyful of jaws. Discover 1998 Nov; 19 (11): 36.
Sereno PC, Beck AL, Dutheil DB, Gado B, Larsson HCE, Lyon GH, Marcot JD, Rauhut OWM, Sadleir RW, Sidor CA, Varricchio DD, Wilson GP, Wilson JA. A long-snouted predatory dinosaur from Africa and the evolution of spinosaurids. Science 1998 Nov 13; 282: 1298–302. Related reading: Hecht J. Fish swam in fear. New Scientist 1998 Nov 21; 160 (2161): 5. Holtz TR Jr. Spinosaurs as crocodile mimics. Science 1998 Nov 13; 282: 1276–7. Monastersky R. Fish-eating dinosaur found in Africa. Science News 1998 Nov 14; 154 (20): 308.
Shoshani J. Understanding proboscidean evolution: a formidable task. Trends in Ecology and Evolution 1998 Dec; 13 (12): 480–7.
Stokstad E. Young dinos grew up fast. Science 1998 Oct 23; 282: 603–4.
Sun G, Dilcher DL, Zheng S, Zhou Z. In search of the first flower: A Jurassic angiosperm, Archaefrustus, from northeast China. Science 1998 Nov 27; 282: 1692–5. Related reading: Crepet WL. The abominable mystery. Science 1998 Nov 27; 282: 1653–4. Hecht J. Floral pioneers were blooming ugly. New Scientist 1998 Dec 5; 160 (2163): 6.
Tarduno JA, Brinkman DB, Renne PR, Cottrell RD, Scher H, Castillo P. Evidence for extreme climatic warmth from late Cretaceous arctic vertebrates. Science 1998 Dec 18; 282: 2241–4. Related reading: Huber BT. Tropical paradise at the Cretaceous poles? Science 1998 Dec 18; 282: 2199–2200. Yam P. Arctic warmth. Scientific American 1999 Mar; 87 (3): 28.
Zimmer C. Into the night. Discover 1998a Nov; 19 (11): 102–15.
Zimmer C. At the Water's Edge: Macroevolution and the Transformation of Life. New York: The Free Press, 1998b.
Zimmer C. The equation of a whale. Discover 1998c Apr; 19 (4): 78–84.
Birds
Ackerman J. Dinosaurs take wing. National Geographic 1998 Jul; 194 (1): 74–99.
[Anonymous]. Counting the fingers of birds and dinosaurs. Science 1998 Apr 17; 280: 355.
Britt BB, Makovicky PJ, Gauthier J, Bonde N. Postcranial pneumatization in Archaeopteryx. Nature 1998 Sep 24; 395: 374–6.
Chen P-J, Dong Z-M, Zhen S-N. An exceptionally well-preserved theropod dinosaur from the Yixian Formation of China. Nature 1998 Jan 8; 391:147–52. Related reading: [Anonymous]. A feathered dinosaur? Discover 1998 May; 19 (5): 19. Unwin DM. Feathers, filaments and theropod dinosaurs. Nature 1998 Jan 3; 391:119–20.
Chiappe LM. Wings over Spain. Natural History 1998 Sep; 107 (7): 30–3. Related reading: [Anonymous]. Old Gobi bird. Discover 1998 Sep; 19 (9): 20.
Chiappe LM, Norell MA, Clark JM. The skull of a relative of the stem-group bird Mononykus. Nature 1998 Mar 19; 392: 276–8.
Dingus L, Rowe T. The Mistaken Extinction: Dinosaur Evolution and the Origin of Birds. New York: WH Freeman and Company, 1998.
Forster CA, Sampson SD, Chiappe LM, Krause DW. The theropod ancestry of birds: New evidence from the late Cretaceous of Madagascar. Science 1998 Mar 20; 279: 1915–9; Related reading: Gibbons A. Missing link ties birds, dinosaurs. Science 1998 Mar 20; 279: 1851–2. Monastersky R. On the line from dinosaurs to birds. Science News 1998 Apr 18; 153 (16): 252. Padian K. Bird, dinosaur link [letter]. Science 1998 May 15; 280: 986–7. Zimmer C. A sickle in the clouds. Discover 1998 June; 19 (6): 32.
Hicks JW, Farmer CG, and others. Lung ventilation and gas exchange in theropod dinosaurs [letters]. Science 1998 Jun 26; 281: 45–48.
Holden C. Big bird laid "dino" eggs? Science 1998 Jan 9; 279: 183. Related reading: Hecht J. Funny old bird. New Scientist 1998 Jan 10; 157 (2116): 18.
Ji Q, Currie PJ, Norell MA, Ji S-A. Two feathered dinosaurs from northeastern China. Nature 1998 Jun 25; 393: 753–61. Related reading: Fischman J. Feathers don't make the bird. Discover 1999 Jan; 20 (1): 48–9. Gibbons A. Dinosaur fossils, in fine feather, show link to birds. Science 1998 Jun 26; 280: 2051. Monastersky R. Feathered dinosaurs found in China. Science News 1998 Jun 27; 153 (26): 404. Padian K. When is a bird not a bird? Nature 1998 Jun 25; 393: 729–30.
Ostrom JH, Padian K, Martin L. Bones of contention [letters]. The Sciences 1998 Sep/Oct; 38 (5): 3, 9, 46–7.
Padian K, Chiappe LM. The origin of birds and their flight. Scientific American 1998 Feb; 278 (2): 38–47. Related reading: Feduccia A, Martin L, Hou L-H, Dodworth A. [Letters]. Scientific American 1998 Jun; 278 (6): 8–8A.
Shipman P. Taking Wing: Archaeopteryx and the Evolution of Bird Flight. New York: Simon & Schuster, 1998. Related reading: Swartz S. Into Jurassic air. Science 1998 Jul 17; 281: 355–6.
Stidham TA. A lower jaw from a Cretaceous parrot. Nature 1998 Nov 5; 396: 29–30.
Thomas ALR, Garner JP. Are birds dinosaurs? Trends in Ecology and Evolution 1998 Apr; 13 (4): 129–30.
Wang J. Scientists flock to explore China's "site of the century". Science 1998 Mar 13; 279: 1626–7.
Zhao X, Xu X. The oldest coelurosaurian. Nature 1998 Jul 16; 394: 234–5. Related reading: [Anonymous]. Pioneer biped. Discover 1998 Apr; 19 (4): 29.
Miscellaneous
Babcock LE. Experimental investigation of the processes of fossilization. Journal of Geosciences Education 1998 May; 46 (3): 252–60.
Hazard EB. Teaching about "intermediate forms". The American Biology Teacher 1998 May; 60 (5): 359–61.
Human Evolution
Agnew N, Demas M. Preserving the Laetoli footprints. Scientific American 1998 Sep; 279 (3): 44–55.
Albianelli A, Azzaroli A, Benvenuti M, Tesfamariam B, Bruni P, Cipriani N, Clarke RJ, Ficcarelli G, Macchiarelli R, Napoleone G, Papini M, Rook R, Sagri M, Tecle TM, Torre D, Villa I, Abbate E. A one-million-year-old Homo cranium from the Danakil (Afar) Depression of Eritrea. Nature 1998 Jun 4; 393: 458–60. Related reading: [Anonymous]. A million–year-old relative. Discover 1998 Sep; 19 (9): 26. Bower B. Ancient skull fills big fossil gap. Science News 1998 Jun 6; 153 (23): 356. Gibbons A. Old, old skull has a new look. Science 1998 Jun 5; 280: 1525.
[Anonymous]. Small beginnings. Earth 1998a Aug; 7 (4): 11–2.
[Anonymous]. An upstanding ape. Discover 1998b Feb; 19 (2): 14.
[Anonymous]. A global winter's tale. Discover 1998c Dec; 19 (12): 30.
Appenzeller T. Art: Evolution or revolution? Science 1998 Nov 20; 282: 1451–4.
Appenzeller T, Clery D, Culotta E. Archaeology: Transitions in prehistory. Science 1998 Nov 20; 282: 1441.
Balter M. Why settle down? The mystery of communities. Science 1998 Nov 20; 282: 1442–5.
Bird M, Olley J, Galbraith R, Lawson E, Laslett G, Yoshida H, Jones R, Fullagar R, Jacobsen G, Hua Q, Roberts R. Optical and radiocarbon dating at Jinmium rock shelter in northern Australia. Nature 1998 May 28; 393: 358–62. Related reading: Bower B. Australian site jumps forward in time. Science News 1998 May 30; 153 (22) 343. Gibbons A. Young ages for Australian rock art. Science 1998 May 29; 280: 1351.
Bower B. Chimp brains show humanlike tilt to left. Science News 1998a Jan 10; 153 (2): 22.
Bower B. Doubts aired over Neandertal bone "flute". Science News 1998b Apr 4; 153 (14): 215.
Bower B. Cutting-edge pursuits in Stone Age. Science News 1998c Apr 11; 153 (15): 238.
Boyce N. Go west, young woman. New Scientist 1998 Oct 31; 160 (2158): 11.
Brainard J. Giving Neandertals their due. Science News 1998 Aug 1; 154 (5): 72–4. Related reading: Bahn PG. Neanderthals emancipated. Nature 1998 Aug 20; 394: 719–21. Current Anthropology 1998 Jun: 39: Supplement.
Cartmill M. The gift of gab. Discover 1998 Nov; 19 (11): 56–64.
Chu JY, Huang W, Kuang SQ, Wang JM, Xu JJ, Chu ZT, Yang ZQ, Lin KQ, Li P, Wu M, Geng ZC, Tan CC, Du RF, Jin L. Genetic relationship of populations in China. Proceedings of the National Academy of Sciences 1998 Sep 29; 95 (20): 11763–8. Related reading: Bower B. Asian dna enters human origins fray. Science News 1998 Oct 3; 154: 212. Cavalli-Sforza LL. The Chinese Human Genome Diversity Project. Proceedings of the National Academy of Sciences 1998; 95 (20): 11501–3. Piazza A. Towards a genetic history of China. Nature 1998 Oct 15; 395: 636–9.
Conroy GC, Weber GW, Seidler H, Tobias PV Kane A, Brunsden B. Endocranial capacity in an early hominid cranium from Sterkfontein, South Africa. Science 1998 Jun 12; 280: 1730–1. Related reading: [Anonymous]. Endocranial Capacity of Early Hominids. Science 1999 Jan 1; 283: 9. Falk D. Hominid brain evolution: Looks can be deceiving. Science 1998 Jun 12; 280: 1714. Holloway RL, and others. Hominid brain volume [letter]. Science 1999 Jan 1; 283: 34–35.
Copley J. Nearly out of Africa. New Scientist 1998 Oct 10; 160 (2155): 12. Related reading: [Anonymous]. The ancient tomb of a young child. Discover 1998 Nov; 19 (11): 28. Bower B. Ancient child's burial on the Nile. Science News 1998 Oct 10; 154 (15): 235.
Gee H. The face of Cinderella. Nature 1998 Dec 10; 396: 521. Related reading: Bower B. Ancient ancestor reveals skeletal stamina. Science News 1998 Dec 19/26; 154 (25/26): 389.
Gibbons A. New study points to Eurasian ape as great ape ancestor. Science 1998a Jul 31; 281: 622–3. Related reading: Lewin R. Getting back to our routes. New Scientist 1998 Aug 1; 159 (2145): 14.
Gibbons A. Which of our genes make us human. Science 1998b Sep 4; 281: 1432–4. Related reading: Chou H-H, Takematsu T, Diaz S, Iber J, Nickerson E, Wright KL, Muchmore EA, Nelson DL, Warren ST, Varki A. A mutation in human CMP-sialic acid hydroxylase occurred after the Homo–Pan divergence. Proceedings of the National Academy of Sciences 1998; 95 (20): 11751–6. Leigh SR and Ryder OA. Chimp research [letters]. Science 1998 Oct 2; 282: 47.
Gibbons A. Calibrating the mitochondrial clock. Science 1998c Jan 2; 279: 28–9.
Hammer MF, Karafet T, Rasanayagam A, Wood ET, Altheide TK, Jenkins T, Griffiths RC,Templeton AR, Zegura SL. Out of Africa and back again: Nested cladistic analysis of human Y chromosome variation. Molecular Biology and Evolution 1998 Apr; 15 (4): 427–41.
Harpending HC, Batzer MA, Gurven M, Jorde LB, Rogers AR, Sherry ST. Genetic traces of ancient demography. Proceedings of the National Academy of Sciences 1998 Feb 17; 95 (4): 1961–7.
Holden C. Humanity's baby steps. Science 1998a Nov 27; 282: 1635. Related reading: [Anonymous]. Out of Africa: Footprints in the sands of time. Discover 1999 Mar; 20 (3): 24.
Holden C. How much like us were the Neandertals? Science 1998b Nov 20; 282: 1456. Related reading: Wolpoff MH. Neandertals: Not so fast [letter]. Science 1998 Dec 11; 282: 1991. Wong K. Ancestral quandary: Neanderthals not our ancestors? Not so fast. Scientific American 1998 Jan; 278 (1): 30–2.
Holden C. No last world on language origins. Science 1998c Nov 20; 282: 1455–8.
Kay RF, Cartmill M, Balow M. The hypoglossal canal and the origin of human vocal behavior. Proceedings of the National Academy of Sciences 1998 Apr 28; 95 (9): 5417–9. Related reading: [Anonymous]. Not so dumb. New Scientist 1998 May 2; 158 (2132): 23. Bower B. Language origins may reside in skull canals. Science News 1998 May 2; 153 (18): 276. Motluk A. Early spinal cords were a talking point. New Scientist 1998 Apr 18; 158 (2130): 11.
Leakey MG, Feibel CS, McDougall I, Ward C, Walker A. New specimens and confirmation of an early age for Australopithecus anamensis. Nature 1998 May 17; 393: 62–6. Related reading: [Anonymous]. The first man? New Scientist 1998 Jun 6; 158 (2137): 24. Bower B. Early hominid rises again. Science News 1998 May 16; 153 (20): 315.
Lewin R. Young Americans. New Scientist 1998a Oct 17; 160 (2156): 24–8.
Lewin R. Principles of Human Evolution. Malden (MA): Blackwell Science, Inc, 1998b.
Lieberman DE. Sphenoid shortening and the evolution of modern human cranial shape. Nature 1998 May 14; 393: 158–62.
Lincoln T. Lucy takes a stroll. Nature 1998 Jul 23; 394: 325.
MacKenzie D. Walk this way. New Scientist 1998 Mar 7; 157 (2124): 24.
McDonald KA. New evidence challenges traditional model of how the New World was settled. The Chronicle of Higher Education 1998 Mar 13; 44 (27): A22–3. Related reading: [Anonymous]. The first Americans circa 20 000 BC. Discover 1998 Jun; 19 (6): 24.
McKie R. The people eaters. New Scientist 1998 Mar 14; 157 (2125): 43–6.
McKinney ML. The juvenilized ape myth — Our "overdeveloped" brain. BioScience 1998 Feb; 48 (2): 109–16.
Mellars P. The fate of the Neanderthals. Nature 1998 Oct 8; 395: 539–40.
Morwood MJ, O'Sullivan PB, Aziz F, Raza A. Fission-track ages of stone tools and fossils on the east Indonesian island of Flores. Nature 1998 Mar 12; 392: 173–6. Related reading: Bower B. Human ancestor may have taken to sea. Science News 1998 Mar 14; 153 (11): 164. Gibbons A. Ancient island tools suggest Homo erectus was a seafarer. Science 1998 Mar 13; 279: 1635–7. Thwaites T. Ancient mariners. New Scientist 1998 Mar 14; 157 (2125): 6; Kunzig R. Erectus Afloat. Discover 1999 Jan; 20 (1): 80.
Pringle H. The slow birth of agriculture. Science 1998 Nov 20; 282: 1446–50.
Schroeder GL. The Science of God. New York: The Free Press, 1997.
Svitil K. No, after you, Afarensis. Discover 1999 Jan; 20 (1): 81.
Weiner S, Xu Q, Goldberg P, Liu J, Bar-Yosef O. Evidence for the use of fire at Zhoukoudian, China. Science 1998 Jul 10; 281: 251–3. Related reading: [Anonymous]. Investigating the possible use of fire at Zhoukoudian, China. Science 1999 Jan 15; 283: 299. Bower B. Ancient fire use flickers inside cave. Science News 1998 Jul 11; 154 (2): 22. Wheeler DL. 'Earliest campfire' now placed in doubt. The Chronicle of Higher Education 1998 Jul 17; 44 (45): A22. Wuethrich B. Geological analysis damps ancient Chinese fires. Science 1998 Jul 10; 281: 165–6.
Zietkiewicz E, Yotova V, Jarnik M, Korab-Laskowska M, Kidd KK, Modiano D, Scozzari R, Stoneking M, Tishkoff S, Batzer M, Labuda D. Genetic structure of the ancestral population of modern humans. Journal of Molecular Evolution 1998 Aug; 47: 146–55.
Chapter 5. Homology
Amores A, Force A, Yan Y-L, Joly L, Amemiya C, Fritz A, Ho RK, Langeland J, Prince V, Wang Y-L, Westerfield M, Ekker M, Postlethwait JH. Zebrafish hox clusters and vertebrate genome evolution. Science 1998 Nov 27; 282: 1711–4. Related reading: Vogel G. Doubled genes may explain fish diversity. Science 1998 Aug 21; 281: 1119–21.
Behe MJ, Sander K, Bender R. Embryology and evolution [letters]. Science 1998 Jul 17; 281: 348–9. Related reading: Richardson MK. Haeckel's embryos, continued [letter]. Science 1998 Aug 28; 281: 1289.
Brooke NM, Garcia-Fernandez J, Holland PWH. The ParaHox gene cluster is an evolutionary sister of the Hox gene cluster. Nature 1998 Apr 20; 392: 920–2.
Cameron RA, Peterson KJ, Davidson EH. Developmental gene regulation and the evolution of large animal body plans. American Zoologist 1998; 38 (4): 609–20.
Dreyer WJ. The area code hypothesis revisited: Olfactory receptors and other related transmembrane receptors may function as the last digits in a cell surface code for assembling embryos. Proceedings of the National Academy of Sciences 1998 Aug 4; 95 (16): 9072–7.
Duboule D, Wilkins AS. The evolution of bricolage. Trends in Genetics 1998 Feb; 14 (2): 54–9.
Gardner DM, Torok MA, Mullen LM, Bryant SV. Evolution of vertebrate limbs: Robust morphology and flexible development. American Zoologist 1998; 38 (4): 659–71.
Gilbert SF. Conceptual breakthroughs in development biology. Journal of Biosciences 1998 Sep; 23 (3): 169–76.
Hall BK. Germ layers and the germ-layer theory revisited: Primary and secondary germ layers, neural crest as a fourth germ layer, homology, and demise of the germ-layer theory. Evolutionary Biology 1998; 30: 121–86.
Hanken J, Richardson MK. Haeckel's embryos [letter]. Science 1998 Feb 27; 279: 1288.
Henry GL, Melton DA. Mixer, a homeobox gene required for endoderm development. Science 1998 Jun 26; 281: 91–6.
Holland LZ, Holland ND. Developmental gene expression in Amphioxus: New insights into the evolutionary origin of vertebrate brain regions, neural crest, and rostrocaudal segmentation. American Zoologist 1998; 38 (4): 647–58.
Kmita-Cunisse M, Loosli F, Bierne J, Gehring WJ. Homeobox genes in the ribbonworm Linea sanguineus: Evolutionary implications. Proceedings of the National Academy of Sciences 1998 Mar 17; 95 (6): 3030–5.
Lee MSY. Similarity, parsimony and conjecture of homology: The chelonian shoulder girdle revisited. Journal of Evolutionary Biology 1998 May; 11: 379–87.
Lewin R. Family feuds. New Scientist 1998 Jan 24; 157 (2118): 36–40.
Martindale MQ, Henry JQ. The development of radial and biradial symmetry: The evolution of bilaterality. American Zoologist 1998; 38 (4): 672–84.
Martinez DE, Bridge D, Masuda-Nakagawa LM, Cartwright P. Cnidarian homeoboxes and the zootype. Nature 1998 Jun 25; 393: 748–9.
Meyer A. Hox gene variation and evolution. Nature 1998 Jan 15; 225–8.
Pendick D. When life got legs. Earth 1998 Aug; 7 (4): 26–33.
Prince VE. Hox genes and segmental patterning of the vertebrate hindbrain. American Zoologist 1998; 38 (4): 634–6.
Richardson MK, Hanken J, Gooneratne ML, Pieau C, Raynaud A, Selwood L, Wright GM. There is no highly conserved embryonic stage in the vertebrates: Implications for current theories of evolution and development. Anatomy and Embryology 1997; 196: 91–106.
Richardson MK, Hanken J, Selwood L, Wright GM, Richards RJ, Pieau C, Raynaud A. Haeckel, embryos, and evolution [letter]. Science 1998 May 15; 280: 983–5.
Schwabe JWR, Rodriguez-Esteban C, Belmonte JCI. Limbs are moving: where are they going? Trends in Genetics 1998 Jun; 14 (6): 229–35.
Strauss E. How embryos shape up. Science 1998 Jul 10; 281: 166–7.
Tautz D. Debatable homologies. Nature 1998 Sep 3; 395: 17–18.
Wray GA, Raff RA. Body builders of the sea. Natural History 1998 Dec/Jan; 107 (10): 38–47.
Chapter 6: Biochemistry
Anderson CL, Canning EU, Okamura B. A triploblast origin for Myxozoa? Nature 1998 Mar 26; 392: 346.
Balavoine G, Adoutte A. One or three Cambrian radiations? Science 1998 Apr 17; 280: 397–8.
Collins AG. Evaluation multiple alternative hypotheses for the origin of Bilateria: An analysis of 18S rRNA molecular evidence. Proceedings of the National Academy of Sciences 1998 Dec 22; 95 (26): 15458–63.
De Ley P, Garey JR, Liu LX, Scheldeman P, Vierstraete A, Vanfleteren JR, Mackey LY, Dorris M, Frisse LM, Vida JT, Thomas WK, Blaxter ML. A molecular evolutionary framework for the phylum Nematoda. Nature 1998 Mar 5; 392: 71–6. Related reading: Anderson RC. Out of order [letter]. Nature 1998 May 14; 393: 10. Nielsen C. Sequences lead to tree of worms. Nature 1998 Mar 5; 392: 25–6.
Gaut BS. Molecular clocks and nucleotide substitution rates in higher plants. Evolutionary Biology 1998; 30: 93–120.
Kumar S, Hedges SB. A molecular timescale for vertebrate evolution. Nature 1998 Apr 30; 392: 917–20. Related reading: Gibbons A. Genes put mammals in age of dinosaurs. Science 1998 May 1; 280: 675–6. McDonald KA. Mammals diversified earlier than believed. The Chronicle of Higher Education 1998 May 29; 44 (38): A21.
Maley LE, Marshall CR. The coming of age of molecular systematics. Science 1998 Jan 23; 279: 505–6.
Normile D. New views of the origins of mammals. Science 1998 Aug 7; 281: 774–5. Related reading: Wong K. Cetacean creation. Scientific American 1999 Jan; 87 (1): 26–30.
Qiu Y-L, Cho Y, Cox JC, Palmer JD. The gain of three mitochondrial introns identifies liverworts as the earliest land plants. Nature 1998 Aug 13; 394: 671–4. Related reading: [Anonymous]. The Ur-plant. Discover 1998 Nov; 19 (11): 26.
Schubart CD, Diesel R, Blair-Hedges S. Rapid evolution to terrestrial life in Jamaican crabs. Nature 1998 May 28; 363–5. Related reading: Tromans A. Land-loving crabs. Nature 1998 May 28; 393: 305.
Springer MS, Westerman M, Kavanagh JR, Burk A, Woodburne MO, Kao DJ, Krajewski C. The origin of the Australasian marsupial fauna and the phyogenetic affinities of the enigmatic monito del monte and marsupial mole. Proceedings of the Royal Society of London Series B 1998 Dec 22; 265 (1413): 2381–6.
Ursing BM, Arnason U. Analyses of mitochondrial genomes strongly support a hippopotamus-whale clade. Proceedings of the Royal Society of London Series B 1998 Dec 7; 265 (1412): 2251–5.
Zardoya R, Meyer A. Complete mitochondrial genome suggests diapsid affinities of turtles. Proceedings of the National Academy of Sciences 1998 Nov 24; 95 (24): 14226–31. Related reading: [Anonymous]. Don't mess with me — my cousin's a dinosaur. New Scientist 1998 Nov 28; 160 (2162): 25. Monastersky R. Turtle genes upset reptilian family tree. Science News 1998 Dec 5; 154 (23): 358.
The Search for Noah's Ark in the Science Curriculum?
On December 16, 1999, the San Bernardino County Sun carried a front page article entitled "Mythic Science", in which a science teacher at a local high school related details about his personal quest to locate Noah's Ark upon Mount Ararat. A television interview of the teacher was aired on February 7, 2000, on the "Evening Edition" program produced by the local PBS affiliate, KVCR TV 24, San Bernardino. Comments made by the teacher in the interviews indicated that he was incorporating material related to his search for Noah's Ark into his public high school science class. In the interviews, the teacher said that he used the Ark Search as "an example of the scientific method" and that he presented alternative theories of geology to his students, including the notion "that there could have been a global event that formed much of the sedimentary rock layers".
The immediate concern raised by these interviews was that the Genesis narrative of the Noachian Flood and related creationist concepts of flood geology were being presented, as science, in the context of a public high school science class. This is not only bad science; it is bad theology in the view of many religious communities, including the Roman Catholic Church. This also appeared to be a violation of the Establishment Clause of the First Amendment of the U.S. Constitution, since the teacher is employed at a public school, is therefore an agent of the government, and, as such, is prohibited from advocating religious claims to his students.
Having scrutinized these interviews, a number of concerned individuals contacted the NCSE and other organizations, formed a coalition to address the issue, and contacted the appropriate school district administration with our concerns. Our efforts have been successful. After about three months since the issue was first raised, the school district has taken steps to ensure that this teacher will stop using material that could be interpreted as creationist in nature and present only the approved science curriculum to his class.
Dealing with this issue has been a valuable learning experience for my associates and me. I would like to share with you some of the lessons we have learned.
As I mentioned before, this has been a valuable learning experience for all of us. The final lesson we have learned is that individuals can, and do, make a difference in the quality of education offered in a community, only if they are willing to stand up, speak out, and be heard. The following quote from Margaret Mead sums it up very well: "Never doubt that a small group of thoughtful, committed citizens can change the world. Indeed, it is the only thing that ever has."
The immediate concern raised by these interviews was that the Genesis narrative of the Noachian Flood and related creationist concepts of flood geology were being presented, as science, in the context of a public high school science class. This is not only bad science; it is bad theology in the view of many religious communities, including the Roman Catholic Church. This also appeared to be a violation of the Establishment Clause of the First Amendment of the U.S. Constitution, since the teacher is employed at a public school, is therefore an agent of the government, and, as such, is prohibited from advocating religious claims to his students.
Having scrutinized these interviews, a number of concerned individuals contacted the NCSE and other organizations, formed a coalition to address the issue, and contacted the appropriate school district administration with our concerns. Our efforts have been successful. After about three months since the issue was first raised, the school district has taken steps to ensure that this teacher will stop using material that could be interpreted as creationist in nature and present only the approved science curriculum to his class.
Dealing with this issue has been a valuable learning experience for my associates and me. I would like to share with you some of the lessons we have learned.
- Do not overreact. Our concern on learning of the teacher's activities was that school authorities might somehow be condoning or turning a blind eye to what the teacher was doing. It soon became apparent that members of the school board and administration were simply not well informed about the issues and that it would take time for them to come up to speed. In hindsight, some portions of our initial letters, though carefully reasoned, were more aggressive in tone than was appropriate. The result was that it probably took more time than was necessary for the school administration to trust us; unfortunately, we were viewed initially as extremists.
- Keep your manner friendly, dignified, and nonconfrontational. Throughout our interactions with school district administrators, we were careful to treat them with respect and as professionals. At one point, maintaining a nonconfrontational demeanor entailed distancing ourselves from potential allies who apparently relished the controversy as much or more than the opportunity to obtain a satisfactory resolution. At another point, we declined the offer of media attention about the issue because we had achieved a cooperative relationship with the school district administration. We decided that sparing the district the publicity would expedite a speedy resolution of the issue. Acting in a nonconfrontational manner enabled our group to communicate effectively with the school district administrators who had the power to resolve the issue.
- Attend school board meetings and introduce yourself to those officials with whom you have corresponded. A friendly handshake helps to establish a personal rapport, and it always helps for names to be connected to faces. When we deliberately passed up the opportunity to comment in the open forum session of a school board meeting, the district administration came to understand that we were not extremists seeking controversy, but concerned, individuals seeking a reasonable solution.
- Do your homework and use available local resources. In our case, local colleges and universities provided our group with two very effective representatives of the scientific and educational communities. Local high schools provided several other concerned science educators. The San Bernardino County Democratic Central Committee also provided valuable assistance in locating concerned parents in the community.
- Do not ignore local religious resources. Our group's connections to religious organizations helped us to find articles and spokespersons that supported curriculum standards that insisted that science, not creationism or religion, should be taught in science classes. Many mainstream religious organizations can be quite supportive of science education and of the separation of religion and government.
- Use available internet resources. The internet proved to be an indispensable source of information in support of our research. We had instant access to background material on the creationist movement, California State science curriculum standards, and relevant court decisions upholding the teaching of science. The NCSE web site is an excellent starting point: http://www.natcenscied.org/.
- Use resources available from national organizations. The NCSE, the ACLU, and Americans United for Separation of Church and State provided information, guidance, and moral support. The NCSE, in particular, served as a clearinghouse for information and for concerned individuals. The NCSE initially connected our group members with one another. Special credit is due Molleen Matsumura of the NCSE. The National Science Teachers Association and the National Research Council of the National Academy of Sciences also proved to be valuable sources of information. Through our contacts with these organizations, our group became more effective and appeared stronger than it might have otherwise.
- Find at least one concerned parent in the local community. Your arguments will carry more weight with the school district if they are made by parents who have children attending local schools. When our group initiated our complaint with the district, we did not know any parents of students in the school district. Not having the help of concerned parents in our group hampered our initial efforts to communicate the urgency of our concerns to the school district.
- Once your homework is done, be willing to go public. The local Public Broadcasting System affiliate, KVCR, offered our group an interview to rebut the earlier interview of the high school teacher. Disclosure to the school district of the willingness of our group's PhD geologist to participate in the rebuttal interview coincided with a timely and appropriate decision by the school district to limit science classroom instruction to established scientific theories.
- Use e-mail to keep your group informed and current. In our group, one member acted as the e-mail clearinghouse and made sure that all members had access to needed information. Not every e-mail went to every member of the group, but most did. Information sharing helped to keep our group working as a team. Having a clearinghouse and conducting peer reviews of all correspondence kept members from hitting the "send" button and regretting it in the morning.
- Know the strengths of your group's members and divide tasks accordingly. In our case, we had individuals with expertise in geology, state and national science curriculum standards, science and theology issues, and the creationist movement and related legal issues. In our communication with the district, each member covered a different perspective: science and geology, state curriculum standards, constitutional and legal issues, or theology. One of our members had extensive experience in the education system and in the political processes surrounding state and national science education standards and served as a mediator between our group and the school district.
As I mentioned before, this has been a valuable learning experience for all of us. The final lesson we have learned is that individuals can, and do, make a difference in the quality of education offered in a community, only if they are willing to stand up, speak out, and be heard. The following quote from Margaret Mead sums it up very well: "Never doubt that a small group of thoughtful, committed citizens can change the world. Indeed, it is the only thing that ever has."
Review: Genes, People, and Languages
This book has the ambitious goal of combining relevant information from the fields of population genetics, archeology, and linguistics into a series of extended essays on human evolution. According to the jacket notes, "Genes, Peoples, and Languages comprises five lectures that serve as a summation of the author's work over several decades, the goal of which has been nothing less than tracking the past 100 000 years of human evolution." Cavalli-Sforza is a premier researcher in this field, with over 20 peer-reviewed papers published within the last 5 years (176 total), all in high ranking prestigious journals. Perhaps most interesting of these was an article with the same title as this book, published in the Proceedings of the National Academy of Sciences in 1997 (PNAS 1997; 94: 7719-24). Strangely, even though a quick review of the PNAS article shows that both it and the book cover similar material, it was left out of the bibliography of Genes, Peoples, and Languages.
In the preface, Cavalli-Sforza states that he believes that, although scientific jargon increases precision and speed of communication between professionals, it hampers communication between disciplines. Consequently, he sought to minimize jargon as much as possible throughout the text. I believe that he succeeded in this task: the book is easy to read and quickly makes important points accessible to a general reader. I was impressed with the ease with which Cavalli-Sforza explained some fairly complex concepts in population genetics without employing jargon or mathematics. He handled with clarity the complexities surrounding the ancestral "Eve" and genetic studies of mitochondrial DNA, as well as analyses of the male-specific Y chromosome. Particularly pleasing were his explanations of the arbitrariness of race and of how superficial characteristics used to mark racial boundaries are only vague reflections of the underlying genetics. I found his perspective on race and genetics to be refreshing and a strong challenge to works such Richard J Herrnstein and Charles Murray's The Bell Curve.
Thanks to this book, I also learned a great deal regarding both linguistics and the history of the human species. I was particularly fascinated by the last 2 chapters of the book, which focused on the evolution of language and culture. That the development of language could be considered the major driving force of culture and progress was a novel concept to me - although it might be considered old hat by anthropologists or linguists. In my mind, that is the main strength of this book. Although I learned very little about my own field (genetics), I came away feeling very enlightened in the fields of both human archeology and linguistics. It was very refreshing to see genetics applied in these other disciplines. I suspect that professionals from the reciprocal fields will have the same opinion. I regard this book as aimed primarily at a lay audience, or educators and researchers whose fields lie outside the scope of the book. If you feel that you belong to one of these categories, then I can recommend this book without reservation.
However, as a researcher and scientist, I found 2 aspects of the book frustrating. My main complaint is with the way that references are used - or, rather, not used. There is a bibliography (86 references), but it seems a bit on the light side considering the scope of the book. I found the lack of referenced sources in the text frustrating because, when I find something interesting, I like to follow up with the references to get further information. In a text like this, where concepts are treated very generally and supporting data are often left out, the lack of references is a glaring omission. I sincerely doubt that the lay reader drawn to a book like this one would be discouraged by citations in the text, and the serious student or researcher would find them highly beneficial. If a second edition of this book is published, it would benefit greatly if sources were cited within the text and the bibliography expanded.
A second caveat is that the book has a tendency to meander and jump around quite a bit. This led to a very "folksy" feel to the translation, and made it comfortable to read. However, if the text were a bit tighter and more linear, I think that it would have been even easier to read and, on the whole, less confusing.
To conclude, I found the strengths of Genes, Peoples, and Languages to be its success in presenting complex concepts and relating them to several scientific disciplines. On the other hand, its weaknesses are its lack of in-depth detail, analyses, and, especially, references that the motivated reader can use to learn more about the topics. The audiences most likely to benefit or enjoy this book are lay persons who are genuinely interested in human evolution but who lack formal exposure to the discipline. I also believe that high school or college educators could easily use this book to link the 3 disciplines - population genetics, archaeology, and linguistics - together. However, researchers or professionals in the fields are likely to be disappointed by the general lack of depth in the text. To be fair, one has to choose an audience to write to, and it is pretty clear that Cavalli-Sforza had in mind a general readership when he wrote this book.
RNCSE 20 (3)
Articles available online are listed below.
Dissecting the Disclaimer
Recently the state of Oklahoma almost adopted a disclaimer to be placed in science textbooks that mention evolution and are used by public schools in the state. (See RNCSE 1999; 19 [5]: 7-8, 1999; 19 [6]: 11-2, and 2000; 20 [1-2]: 21). RNCSE readers will recognize that the wording of the Oklahoma disclaimer is taken directly from the infamous original textbook disclaimer proposed for textbooks in Alabama (see NCSE Reports 1995; 15 [4]:10-1). Unfortunately, the disclaimer is laden with scientific inaccuracies and distortions that will confuse students about the nature of science and the science of evolution. Such statements place an unwelcome burden on teachers, who must correct this misinformation for their students. They also introduce the dangerous precedent of setting official statements by public officials at odds with scientific accuracy and good educational practice.
What follows is a line-by-line analysis of the scientific accuracy of the disclaimer. The text of the disclaimer is set in boldface type, and my commentary is in plain type.
Message from the Oklahoma State Textbook Committee:
This textbook discusses evolution, a controversial theory, which some scientists present as scientific explanation for the origin of living things, such as plants and humans.
This statement is a deliberate attempt to mislead young readers about the scientific standing of evolutionary biology. Within the scientific community, evolution is anything but controversial. Rather, as the National Academy of Sciences states, evolution is "the most important concept in modern biology" (NAS 1998, viii). Saying that "some" scientists present evolution as the explanation for the origin of species is equally misleading. It is like saying that "some" scientists believe that matter is composed of small units they call atoms. That statement would also be true, but would convey a false sense of uncertainty regarding atomic theory. A more accurate statement would tell students that evolution is accepted by the vast majority of life scientists around the world, and by every leading scientific organization in the United States including the National Academy of Sciences, as the best available explanation for the origin of species.
No one was present when life first appeared on earth.
Absolutely correct.
Therefore, any statement about life's origins should be considered as theory, not fact.
This statement manifests a serious misunderstanding of the scientific usage of the terms "theory" and "fact". A theory in science is an explanation of a natural phenomenon, and a fact is a confirmed observation. An example of a fact would be that there is great consistency in the sequence of fossils in the fossil record, with no major branch of the tree of life being out of order (for example, fossils of mammals are never found in the Devonian Period - a time marked by the diversification of bony fishes and the appearance of the first amphibians and insects). Another fact is that living species tend to be found where their fossil ancestors are also found. We make sense of these and many other confirmed observations, or facts, with the explanation that living things share common ancestors, from which they have diverged. This explanation is the theory of evolution, an extremely strong and well-supported theory. The disclaimer will confuse students about these important elements of science. Theories explain facts, and contrary to the impression given by the disclaimer, this means that theories are more important than facts.
The disclaimer also will confuse students about the nature of science by implying that science concerns only directly observable phenomena. Actually, many scientific discoveries are made about phenomena that are not directly observable, such as those that are too far away (astronomy) or too small (particle physics) as well as those that occurred in the past (geology and evolutionary biology). That "no one was there to see it" does not mean that it cannot be studied scientifically or that we cannot have confidence in our explanations.
Ironically, well-written science textbooks place even less confidence in current ideas about how life may have originated than the disclaimer does. Typically, ideas about the origin of life are regarded as hypotheses, placing them a rung lower on the scientific hierarchy of ideas than the textbook committee was willing to do. (A typical example is this: "How then did life begin? ... Although several hypotheses have tried to explain how life may have arisen, we may never know the answers" [Miller and Levine 1998, 398].) The disclaimer makes a serious error by elevating current hypotheses about the origin of life to the status of theories (which would mean that they are generally accepted by the scientific community).
The word evolution may refer to many types of change. Evolution describes changes that occur within a species. (White moths, for example, may evolve into gray moths). This process is micro evolution, which can be observed and described as fact.
Evolutionary biologists use "microevolution" to refer to the processes (most of them having to do with genetics) that produce evolutionary changes in populations of species: natural selection, mutation, migration, genetic drift, and other mechanisms. The writers of the disclaimer apparently share this definition, and are correct in noting that we can observe these processes at work.
Evolution may also refer to the change of one living thing into another, such as reptiles into birds. This process, called macro evolution, has never been observed and should be considered a theory. Here the writers of the disclaimer do not use the scientific meaning of the crucial term. "Macroevolution", for evolutionary biologists, refers to a range of processes having to do with the pattern of evolutionary change: how groups are related to one another above the level of the species, rates of evolutionary change, the behavior of lineages over time, and so forth. But in the disclaimer, the term "macroevolution" means merely the general principle of evolution: that living things have descended with modification from common ancestors. This is not what macroevolution means in science, and to use the term as a synonym for evolution misleads and confuses students.
Clearly, the writers of the disclaimer want students to reject the idea that living things have a common ancestry, and they are in the bind of having to accept well-understood and widely-demonstrated processes of evolutionary change, which, over time, would result in evolution. The reason for this is at bottom a sectarian religious belief known as "special creation": that all living things were created in their present form and did not descend with modification from common ancestors. Special creation is not supported by science - regardless of how the authors of the disclaimer attempt to redefine scientific terms.
Evolution is not rigidly divided into two types of change -microevolution and macroevolution - as the disclaimer implies. Macroevolution, for example, may be used to refer to the process of speciation, to major evolutionary transformations, or both. Most importantly, it is commonly accepted among evolutionary biologists that microevolutionary changes (whether caused by natural selection or by genetic drift) can accumulate so as to cause reproductive isolation, hence leading to speciation or macroevolution. Has macroevolution "never been observed"? A recent study (Reznick and others 1997) evaluated the observed rates of evolutionary change in populations of guppies (Poecilia reticulata) in the wild. The rates of evolutionary change observed were "up to 7 orders of magnitude greater than rates inferred from the paleontological record." In other words, field studies of natural selection show rates of change easily more than large enough to account for the macroevolutionary changes documented in the fossil record. This is just one of many studies that cast serious doubt on the assertion that macroevolution has "never been observed." (The researchers also note: "Our work cannot address the efficacy of mechanisms other than natural selection, but it extends our understanding of what is attainable through this process. It is part of a growing body of evidence that the rate and patterns of change attainable through natural selection are sufficient to account for the patterns observed in the fossil record" (Reznick and others 1997: 1936).
Evolution also refers to the unproven belief that random, undirected forces produced a world of living things.
This statement is false on 2 counts. Evolution is not a "random" process, and to characterize it so seriously misleads students. Natural selection, the most important force driving evolutionary change, is not random at all, but an observable, verifiable process that fine-tunes variation in populations of a species to the demands of the environment in which they live. It is true, of course, that variation in a species arises from sources such as mutation and sexual recombination, which are inherently unpredictable. Therefore evolution, like any historical process, can be influenced by random forces.
But a larger problem with this statement is the attribution to evolution of an idea outside of science. Whether evolution is "undirected" or "directed" is a matter for theology or philosophy, not of science. Writers of the disclaimer wish for students, most of whom are religious, to believe that acceptance of evolution is incompatible with faith. This is demonstrably false: far too many scientists (and clergy) accept both evolution and a God who creates through evolution. Students should not be taught that evolution equates with atheism, yet, incredibly, that is exactly what this portion of the disclaimer says.
There are many unanswered questions about the origin of life, which are not mentioned in your textbook, ...
It is absolutely true that there are "many unanswered questions about the origin of life", and most biology textbooks point this out in far greater (and more accurate) detail than does the disclaimer. Indeed, there are unanswered questions in each and every area of biology, making biology an exciting and vigorous discipline. The disclaimer, however, does not seek to draw student attention to unanswered questions in biochemistry, ecology, or physiology; it singles out evolution for special attention, as if it had special difficulties that other fields do not.
Scientifically, this is not correct, and the next few sentences of the disclaimer show just how badly informed its authors were:
... including: Why did the major groups of animals suddenly appear in the fossil record, known as the Cambrian Explosion?
This question seriously misleads students about the actual natural history of this planet. The term "major group" lacks scientific meaning. Many students, for example, might regard the mammals as a major group. Mammals, however, did not appear during the Cambrian explosion, but rather in the Triassic, nearly 300 million years later. The same can be said of birds, insects, reptiles, and amphibians, each of which are major groups in the ordinary meaning of the term, and none of which appeared in the Cambrian period. Clearly, the authors of the statement could have prevented such confusion by referring only to the animal phyla instead of "major groups".
Unfortunately, even if they had done so, the question would still be misleading. Not all animal phyla originated during the Cambrian. Compounding this serious mistake, the authors of the disclaimer seem to be unaware that the first multicellular animals appeared on earth during the Ediacaran Period, and many predate the Cambrian by more than 100 million years.
Why have no new major groups of living things appeared in the fossil record in a long time?
This peculiar question requires students to determine what is meant by a "major group" and also what is meant by "a long time". Neither term, of course, has any scientific meaning. One might regard 100 years as a long time, and it is indeed true that no new phyla have originated in the last 100 years. However, by standards of geologic time, one of the most important "major groups of living things" did indeed originate recently. Flowering plants (the Anthophyta) appeared for the first time in the Cretaceous, roughly 125 million years ago. Flowering plants appeared only in the last 3% of the 4.5 billion years of the planet's geologic history, which certainly qualifies as recent. Therefore, this question, which overlooks the recent evolutionary appearance of flowering plants, makes blatantly wrong presuppositions.
Why do major groups of plants and animals have no transitional forms in the fossil record?
This question also makes blatantly wrong presuppositions. The fossil record is, in fact, replete with splendid examples of transitional forms, as the National Academy of Sciences has taken pains to point out:
So many intermediate forms have been discovered between fish and amphibians, between amphibians and reptiles, between reptiles and mammals, and along the primate lines of descent that it often is difficult to identify categorically when the transition occurs from one to another particular species. Actually, nearly all fossils can be regarded as intermediates in some sense; they are life forms that come between the forms that preceded them and those that followed (NAS 1999: 21).
How did you and all living things come to possess such a complete and complex set of instructions for building a living body?
This is an excellent question, and students would be well-advised to keep it in mind as they study biology. They may wonder why, for example, the "complex set of instructions" referred to by this sentence includes the genetic remnants of an ancient infection by an HIV-like virus. The interesting fact about these genetic remnants is that they are found not only in humans, but in our closest primate relatives, indicating that these viral DNA sequences entered the genome roughly 30 million years ago. As the investigators who made this discovery pointed out, the existence of identical sequences in closely related species is "very good evidence" that we share a common ancestry with these other primates (Yang and others 1999). As the National Academy of Sciences has written, "compelling lines of evidence demonstrate beyond any reasonable doubt that evolution occurred as a historical process and continues today" (NAS 1998, 16).
Study hard and keep an open mind. Someday you may contribute to the theories of how living things appeared on earth.
At last, some excellent advice!
By any standard, this disclaimer fails even an undemanding test of scientific literacy. Twelve statements are included in the disclaimer. Of these, only 5 are free of major errors. Three are seriously misleading, and 4 are downright false. A biology teacher grading this disclaimer based on the proportion of correct answers would calculate a score of no more than 42% - a failing grade.
Our students deserve better.
To be sure, the disclaimer's admonition that students study hard and keep an open mind fits the best traditions of scientific study. But keeping an open mind does not mean that students should intentionally be taught nonsense, nor does it mean that we should pretend to know less than we do about the natural history of this planet and the origins of species, including our own. Healthy skepticism is at the core of a scientific education, but elevating falsehoods and half-truths to the status of scientific theory most definitely is not.
I would argue that any textbook, indeed, any course in the biological sciences should tell students the plain and simple truth, as described in a single sentence by the National Academy of Sciences: that "[b]iological evolution is the best scientific explanation we have for the enormous range of observations about the living world" (NAS 1999: 28).
What follows is a line-by-line analysis of the scientific accuracy of the disclaimer. The text of the disclaimer is set in boldface type, and my commentary is in plain type.
Message from the Oklahoma State Textbook Committee:
This textbook discusses evolution, a controversial theory, which some scientists present as scientific explanation for the origin of living things, such as plants and humans.
This statement is a deliberate attempt to mislead young readers about the scientific standing of evolutionary biology. Within the scientific community, evolution is anything but controversial. Rather, as the National Academy of Sciences states, evolution is "the most important concept in modern biology" (NAS 1998, viii). Saying that "some" scientists present evolution as the explanation for the origin of species is equally misleading. It is like saying that "some" scientists believe that matter is composed of small units they call atoms. That statement would also be true, but would convey a false sense of uncertainty regarding atomic theory. A more accurate statement would tell students that evolution is accepted by the vast majority of life scientists around the world, and by every leading scientific organization in the United States including the National Academy of Sciences, as the best available explanation for the origin of species.
No one was present when life first appeared on earth.
Absolutely correct.
Therefore, any statement about life's origins should be considered as theory, not fact.
This statement manifests a serious misunderstanding of the scientific usage of the terms "theory" and "fact". A theory in science is an explanation of a natural phenomenon, and a fact is a confirmed observation. An example of a fact would be that there is great consistency in the sequence of fossils in the fossil record, with no major branch of the tree of life being out of order (for example, fossils of mammals are never found in the Devonian Period - a time marked by the diversification of bony fishes and the appearance of the first amphibians and insects). Another fact is that living species tend to be found where their fossil ancestors are also found. We make sense of these and many other confirmed observations, or facts, with the explanation that living things share common ancestors, from which they have diverged. This explanation is the theory of evolution, an extremely strong and well-supported theory. The disclaimer will confuse students about these important elements of science. Theories explain facts, and contrary to the impression given by the disclaimer, this means that theories are more important than facts.
The disclaimer also will confuse students about the nature of science by implying that science concerns only directly observable phenomena. Actually, many scientific discoveries are made about phenomena that are not directly observable, such as those that are too far away (astronomy) or too small (particle physics) as well as those that occurred in the past (geology and evolutionary biology). That "no one was there to see it" does not mean that it cannot be studied scientifically or that we cannot have confidence in our explanations.
Ironically, well-written science textbooks place even less confidence in current ideas about how life may have originated than the disclaimer does. Typically, ideas about the origin of life are regarded as hypotheses, placing them a rung lower on the scientific hierarchy of ideas than the textbook committee was willing to do. (A typical example is this: "How then did life begin? ... Although several hypotheses have tried to explain how life may have arisen, we may never know the answers" [Miller and Levine 1998, 398].) The disclaimer makes a serious error by elevating current hypotheses about the origin of life to the status of theories (which would mean that they are generally accepted by the scientific community).
The word evolution may refer to many types of change. Evolution describes changes that occur within a species. (White moths, for example, may evolve into gray moths). This process is micro evolution, which can be observed and described as fact.
Evolutionary biologists use "microevolution" to refer to the processes (most of them having to do with genetics) that produce evolutionary changes in populations of species: natural selection, mutation, migration, genetic drift, and other mechanisms. The writers of the disclaimer apparently share this definition, and are correct in noting that we can observe these processes at work.
Evolution may also refer to the change of one living thing into another, such as reptiles into birds. This process, called macro evolution, has never been observed and should be considered a theory. Here the writers of the disclaimer do not use the scientific meaning of the crucial term. "Macroevolution", for evolutionary biologists, refers to a range of processes having to do with the pattern of evolutionary change: how groups are related to one another above the level of the species, rates of evolutionary change, the behavior of lineages over time, and so forth. But in the disclaimer, the term "macroevolution" means merely the general principle of evolution: that living things have descended with modification from common ancestors. This is not what macroevolution means in science, and to use the term as a synonym for evolution misleads and confuses students.
Clearly, the writers of the disclaimer want students to reject the idea that living things have a common ancestry, and they are in the bind of having to accept well-understood and widely-demonstrated processes of evolutionary change, which, over time, would result in evolution. The reason for this is at bottom a sectarian religious belief known as "special creation": that all living things were created in their present form and did not descend with modification from common ancestors. Special creation is not supported by science - regardless of how the authors of the disclaimer attempt to redefine scientific terms.
Evolution is not rigidly divided into two types of change -microevolution and macroevolution - as the disclaimer implies. Macroevolution, for example, may be used to refer to the process of speciation, to major evolutionary transformations, or both. Most importantly, it is commonly accepted among evolutionary biologists that microevolutionary changes (whether caused by natural selection or by genetic drift) can accumulate so as to cause reproductive isolation, hence leading to speciation or macroevolution. Has macroevolution "never been observed"? A recent study (Reznick and others 1997) evaluated the observed rates of evolutionary change in populations of guppies (Poecilia reticulata) in the wild. The rates of evolutionary change observed were "up to 7 orders of magnitude greater than rates inferred from the paleontological record." In other words, field studies of natural selection show rates of change easily more than large enough to account for the macroevolutionary changes documented in the fossil record. This is just one of many studies that cast serious doubt on the assertion that macroevolution has "never been observed." (The researchers also note: "Our work cannot address the efficacy of mechanisms other than natural selection, but it extends our understanding of what is attainable through this process. It is part of a growing body of evidence that the rate and patterns of change attainable through natural selection are sufficient to account for the patterns observed in the fossil record" (Reznick and others 1997: 1936).
Evolution also refers to the unproven belief that random, undirected forces produced a world of living things.
This statement is false on 2 counts. Evolution is not a "random" process, and to characterize it so seriously misleads students. Natural selection, the most important force driving evolutionary change, is not random at all, but an observable, verifiable process that fine-tunes variation in populations of a species to the demands of the environment in which they live. It is true, of course, that variation in a species arises from sources such as mutation and sexual recombination, which are inherently unpredictable. Therefore evolution, like any historical process, can be influenced by random forces.
But a larger problem with this statement is the attribution to evolution of an idea outside of science. Whether evolution is "undirected" or "directed" is a matter for theology or philosophy, not of science. Writers of the disclaimer wish for students, most of whom are religious, to believe that acceptance of evolution is incompatible with faith. This is demonstrably false: far too many scientists (and clergy) accept both evolution and a God who creates through evolution. Students should not be taught that evolution equates with atheism, yet, incredibly, that is exactly what this portion of the disclaimer says.
There are many unanswered questions about the origin of life, which are not mentioned in your textbook, ...
It is absolutely true that there are "many unanswered questions about the origin of life", and most biology textbooks point this out in far greater (and more accurate) detail than does the disclaimer. Indeed, there are unanswered questions in each and every area of biology, making biology an exciting and vigorous discipline. The disclaimer, however, does not seek to draw student attention to unanswered questions in biochemistry, ecology, or physiology; it singles out evolution for special attention, as if it had special difficulties that other fields do not.
Scientifically, this is not correct, and the next few sentences of the disclaimer show just how badly informed its authors were:
... including: Why did the major groups of animals suddenly appear in the fossil record, known as the Cambrian Explosion?
This question seriously misleads students about the actual natural history of this planet. The term "major group" lacks scientific meaning. Many students, for example, might regard the mammals as a major group. Mammals, however, did not appear during the Cambrian explosion, but rather in the Triassic, nearly 300 million years later. The same can be said of birds, insects, reptiles, and amphibians, each of which are major groups in the ordinary meaning of the term, and none of which appeared in the Cambrian period. Clearly, the authors of the statement could have prevented such confusion by referring only to the animal phyla instead of "major groups".
Unfortunately, even if they had done so, the question would still be misleading. Not all animal phyla originated during the Cambrian. Compounding this serious mistake, the authors of the disclaimer seem to be unaware that the first multicellular animals appeared on earth during the Ediacaran Period, and many predate the Cambrian by more than 100 million years.
Why have no new major groups of living things appeared in the fossil record in a long time?
This peculiar question requires students to determine what is meant by a "major group" and also what is meant by "a long time". Neither term, of course, has any scientific meaning. One might regard 100 years as a long time, and it is indeed true that no new phyla have originated in the last 100 years. However, by standards of geologic time, one of the most important "major groups of living things" did indeed originate recently. Flowering plants (the Anthophyta) appeared for the first time in the Cretaceous, roughly 125 million years ago. Flowering plants appeared only in the last 3% of the 4.5 billion years of the planet's geologic history, which certainly qualifies as recent. Therefore, this question, which overlooks the recent evolutionary appearance of flowering plants, makes blatantly wrong presuppositions.
Why do major groups of plants and animals have no transitional forms in the fossil record?
This question also makes blatantly wrong presuppositions. The fossil record is, in fact, replete with splendid examples of transitional forms, as the National Academy of Sciences has taken pains to point out:
So many intermediate forms have been discovered between fish and amphibians, between amphibians and reptiles, between reptiles and mammals, and along the primate lines of descent that it often is difficult to identify categorically when the transition occurs from one to another particular species. Actually, nearly all fossils can be regarded as intermediates in some sense; they are life forms that come between the forms that preceded them and those that followed (NAS 1999: 21).
How did you and all living things come to possess such a complete and complex set of instructions for building a living body?
This is an excellent question, and students would be well-advised to keep it in mind as they study biology. They may wonder why, for example, the "complex set of instructions" referred to by this sentence includes the genetic remnants of an ancient infection by an HIV-like virus. The interesting fact about these genetic remnants is that they are found not only in humans, but in our closest primate relatives, indicating that these viral DNA sequences entered the genome roughly 30 million years ago. As the investigators who made this discovery pointed out, the existence of identical sequences in closely related species is "very good evidence" that we share a common ancestry with these other primates (Yang and others 1999). As the National Academy of Sciences has written, "compelling lines of evidence demonstrate beyond any reasonable doubt that evolution occurred as a historical process and continues today" (NAS 1998, 16).
Study hard and keep an open mind. Someday you may contribute to the theories of how living things appeared on earth.
At last, some excellent advice!
By any standard, this disclaimer fails even an undemanding test of scientific literacy. Twelve statements are included in the disclaimer. Of these, only 5 are free of major errors. Three are seriously misleading, and 4 are downright false. A biology teacher grading this disclaimer based on the proportion of correct answers would calculate a score of no more than 42% - a failing grade.
Our students deserve better.
To be sure, the disclaimer's admonition that students study hard and keep an open mind fits the best traditions of scientific study. But keeping an open mind does not mean that students should intentionally be taught nonsense, nor does it mean that we should pretend to know less than we do about the natural history of this planet and the origins of species, including our own. Healthy skepticism is at the core of a scientific education, but elevating falsehoods and half-truths to the status of scientific theory most definitely is not.
I would argue that any textbook, indeed, any course in the biological sciences should tell students the plain and simple truth, as described in a single sentence by the National Academy of Sciences: that "[b]iological evolution is the best scientific explanation we have for the enormous range of observations about the living world" (NAS 1999: 28).
References
Miller KR, Levine J. Biology: The Living Science. Upper Saddle River (NJ): Prentice-Hall 1998.National Academy of Sciences (NAS). Teaching about Evolution and the Nature of Science. Washington DC: National Academy Press 1998.
National Academy of Sciences (NAS). Science and Creationism: A View from the National Academy, 2nd. ed. Washington DC: National Academy Press 1999.
Reznick DN, Shaw FH, Rodd FH, Shaw RG. Evaluation of the Rate of Evolution in Natural Populations of Guppies (Poecilia reticulata). Science 1997 Mar 28; 275: 1934-7.
Yang J, Bogerd HP, Peng S, Heather Wiegand H, Truant R, Cullen BR. An ancient family of human endogenous retroviruses encodes a functional homolog of the HIV-1 Rev protein. Proceedings of the National Academy of Sciences 1999 Nov 9; 96 [23]: 13404-8.
Nuclear Isochrons
Some chemical elements have isotopes that are inherently unstable and undergo radioactive decay. (Isotopes of the same element always have the same number of charged protons in each atomic nucleus, but have different numbers of noncharged neutrons. Isotopes of a single element act the same chemically, but often behave differently as regards radioactivity or other nuclear reactions.) Each radioactive isotope has a remarkably constant decay rate. These can be measured quite accurately, and most are constant under a huge range of conditions (temperature, pressure, and so on). The laws of physics do not tell us which atoms of a given isotope (say, uranium-238) will decay at any given time; but they do tell us how long it will take for, say, half of the atoms to decay — this duration is called the "half-life"; it is independent of the size of the sample. It is a lot like insurance mortality tables — for a given age group, actuaries cannot predict which individuals are good risks, but they can predict things such as the average life expectancy of members of the group and how long it will take for half of the group to succumb to accidents or natural causes.
"Simple" radioactive dating can be visualized as using a kind of atomic hourglass. The radioactive "parent" decays into a "daughter" isotope (often of a different element, since radioactive decays usually involve charged particles). So, if both parent and daughter elements are present, the ratio of parent isotope to daughter isotope can give a clue to the age of the sample. If there is more parent than daughter, the sample is still young (the top of the hourglass is still mostly full). If there is less parent than daughter, the sample is old (most of the sand is at the bottom of the hourglass).
But simple dating techniques can be distorted in several ways. What if there were some of the daughter isotope in the sample when it was formed? (Or, by analogy, what if the hourglass had some sand already in the bottom vessel when the hourglass was first placed upright?) What if the sample were not a "closed system", and isotopes (either parent or daughter) could enter or leave the system? (What if there were holes in either vessel of the hourglass that could let sand grains in or out?) Such contingencies clearly could affect estimates of how long the "clock" has been running.
To give a concrete example, suppose that we examine 3 different minerals from a rock, labeled A, B, and C, and that isotopic tests revealed the relative amounts of 3 chemical isotopes in these minerals. The parent isotope is rubidium-87 (87Rb for short). It is radioactive, has 37 protons and 50 neutrons (for a total of 87 nucleons), and beta-decays to strontium-87 with a half-life of 49 billion years. The daughter isotope, strontium-87 (87Sr), has 38 protons and 49 neutrons (for a total of 87 nucleons). 87Sr is formed when one neutron of a 87Rb atom decays to a proton, ejecting an electron (or "beta ray"). A third isotope required is strontium-86 (86Sr); this is not involved in any radioactive reactions (and thus is "non-radiogenic").
The present-day relative amounts of the isotopes in our fictitious example are:
| Mineral | 87Rb | 87Sr | 86Sr |
| A | 60 | 80 | 40 |
| B | 30 | 60 | 60 |
| C | 10 | 60 | 100 |
These numbers are purely hypothetical — they were chosen so the explanation would be easy to understand. I decided to make the rock 49 billion years old, one half-life of rubidium. (Yes, that is much older than the universe, but this is merely an example.)
If we were to apply the "simple" dating method to A, B, and C, we would arrive at 3 different ages, assuming that there was no initial daughter isotope (87Sr) when the rock formed. For mineral A, all 80 units of 87Sr would be assumed to have once been 87Rb, so the initial amount of 87Rb would be 60 + 80 = 140. The corresponding age works out to be 1.222 half-lives, or about 60 billion years. [T = T1/2 log2((87Rb + 87Sr) / 87Rb) = 49 BY log2(140 / 60)]. Similarly, mineral B would appear to have an age of 78 BY, and mineral C would appear to have an age of 138 BY. Thus the presence of initial daughter atoms devastates the validity of "simple" dating methods.
There are 3 important questions to consider when choosing a mineral sample for radiometric dating: (1) Is the rock a good sample for radioactive dating? (2) What was the initial amount of daughter product (87Sr) in the rock at the time it formed out of a melt? (3) How old is the rock? The isochron technique provides a way to answer these questions.
Imagine going back in time 49 billion years to observe the rock as it is crystallizing from a melt. The rock has both isotopes of strontium: the daughter product 87Sr and non-radiogenic 86Sr. Because these all have nearly identical chemical characteristics, they are mixed in equal ratios throughout the melted rock, much as a drop of food coloring stirred into a glass of water quickly diffuses into a uniform hue. Ratios are the "secret" of the isochron method, and we need just 2 ratios: the ratio of the radioactive parent isotope (87Rb) to the non-radiogenic isotope (86Sr), and the ratio of the daughter isotope (87Rb) to the same non-radiogenic isotope (86Sr). These are given in the following table for the assumed time of crystallization (49 BY ago).
The rubidium-heavy mineral A has the highest ratio; A’s ratio of parent isotope to non-radiogenic isotope is 120 / 40 = 3.0. In contrast, the rubidium-poor mineral C has the lowest ratio; C’s ratio of parent isotope to non-radiogenic isotope is 20 / 100 = 0.2. Note that all of the minerals have the same ratio of daughter isotope to non-radiogenic isotope: 0.5, or 1/2. This is a direct result of the uniform mixing of the melted isotopes.
Now let us return to the present and see what has happened to our rock. The next table shows the present-day amounts and ratios of the isotopes.
Because the time elapsed since the rock solidified is one half-life of 87Rb, half of the ancient amount will have decayed by the present. So for mineral A, which started with 120 units of 87Rb, now 60 remain, with the other 60 converted to the daughter isotope (87Sr). Thus, as the 87Rb amount drops from 120 to 60, the 87Sr count goes from 20 (49 BYa) to 80 (now). The story is similar for mineral B, which has an 87Rb change of 60 down to 30, and a corresponding 87Sr increase of 30 up to 60. Try the rule out on mineral C to see for yourself how this works. The important thing is that the ratios have changed also — the 87Rb ratios all dropped, and the 87Sr ratios, which used to all be 1/2, are now quite different (ranging from 0.6 to 2.0).
So what is an isochron, anyway? If the results of the preceding tables are graphed with the parent isotope ratio as the horizontal axis, and the daughter isotope ratio as the vertical axis, then the slope of the isochron — the line connecting the points for the various minerals at the same time (as the etymology of the name "isochron" suggests) — is directly related to the age of the rock. Two such isochrons are shown below: the horizontal one labeled 49 BYa, and the slanted one (lower left to upper right) labeled NOW.
The lines with arrows represent the changes in those single minerals over time. For example, A’s 87Rb/86Sr ratio drops from 3.0 to 1.5, while its 87Sr/86Sr ratio rises from 0.5 to 2.0. Compare the plot to the ratios in the preceding tables to see where the isochrons come from.
How is the isochron’s slope related to the age of the rock? Let us consider one more example — that of the same rock, 49 BY in the future (long after our sun has turned into a smoldering dwarf star).
The slope of the far-future isochron is (2.75 - 0.65) / (0.75 - 0.05) = 2.1 / 0.7 = 3.0. The age is obtained by adding 1.0 to the slope, and then stating the sum as a power of two; that power is the age, in half-lives. For a slope of 3, 3 + 1 = 4 = 22, so the age is 2 half-lives. For a slope of 1 (present-day), 1 + 1 = 2 = 21, so the age is 1 half-life. And for a slope of 0.0 (49 BY ago), 0 + 1 = 1 = 20, so the age is zero. In general, the number of half-lives is the base 2 logarithm of (the isochron’s slope + 1). For a slope of 7, slope + 1 = 8 = 23, which means 3 half-lives.
When applied correctly, the isochron method provides a powerful way to tackle some of the problems encountered with "simple" dating techniques. For one thing, if the sample minerals did not solidify at the same time but were mashed together, the points will generally not lie on a straight line. And when this scattering is observed, the sample is recognized to be unusable for dating with the method. It is like a built-in quality check on the reliability of the result. For another thing, the possibility of having some of the daughter isotope already present in the rock when it formed can be handled . This initial amount is revealed by the isochron method — as the value on the 87Sr/86Sr axis where the isochron crosses (0.5 in all the examples). And since the age depends on the isochron slope, the initial amount does not affect the age determination (unlike "simple" dating).
But the method is not infallible. For example cases of non-uniform mixing, or conglomeration of certain types of rocks, can sometimes lead to "false" or "fictitious" isochrons — isochrons that do not represent the true age of the rock. These possible pitfalls are discussed in Bernard-Griffiths (1989) and Faure (1986). There are methods to counteract these problems, such as taking more mineral samples, performing mixture analyses on more than one element, and by checking dates by independent means (such as looking at different parent/daughter pairs). (For more details on this and other methods, see the chapter on dating techniques in Dalrymple [1991] and York and Dalrymple [2000].) When such checks are made, confidence in the results is greatly increased. For example, the St Severin meteorite was dated with three different methods (Rb-Sr, Sm-Nd, and Ar-Ar) as being between 4.4 and 4.6 billion years old (Dalrymple 1991, 288).
Creationists love to attack such methods by claiming that we do not really know if radioactive decay rates are constant over time. They point out no human was around back then, so who knows for sure? They also hypothesize that decay rates varied during supernatural events (the Creation, the Flood), but of course they do not test these hypotheses. One interesting point against the creationists is the fact that, if decay rates did change over time, the points on an isochron plot would be forced off the isochron line and would appear quite scattered. The very fact that isochrons do work in many cases is powerful evidence that decay rates have, in fact, remained constant for billions of years.
This article originally appeared in NMSR Reports 1997 May; 3 (5): 5–7. It is reprinted and abridged with permission.
References
Bernard-Griffiths J.Dalrymple GB. The Age of the Earth. Stanford (CA): Stanford University Press 1991.
Faure G. Principles of Isotope Geology>. 2nd ed. NY: John Wiley and Sons, 1989.
York D, Dalrymple GB. Comments on a creationist’s irrelevant discussion of isochrons. Reports of the National Center for Science Education> 2000 May/Jun; 20 [3]: xx–xx.
Radiometric Dating Does Work!
Radiometric dating of rocks and minerals using naturally occurring, long-lived radioactive isotopes is troublesome for young-earth creationists because the techniques have provided overwhelming evidence of the antiquity of the earth and life. Some so-called creation scientists have attempted to show that radiometric dating does not work on theoretical grounds (for example, Arndts and Overn 1981; Gill 1996) but such attempts invariably have fatal flaws (see Dalrymple 1984; York and Dalrymple 2000). Other creationists have focused on instances in which radiometric dating seems to yield incorrect results. In most instances, these efforts are flawed because the authors have misunderstood or misrepresented the data they attempt to analyze (for example, Woodmorappe 1979; Morris HM 1985; Morris JD 1994). Only rarely does a creationist actually find an incorrect radiometric result (Austin 1996; Rugg and Austin 1998) that has not already been revealed and discussed in the scientific literature.
The creationist approach of focusing on examples where radiometric dating yields incorrect results is a curious one for two reasons. First, it provides no evidence whatsoever to support their claim that the earth is very young. If the earth were only 6000–10 000 years old, then surely there should be some scientific evidence to confirm that hypothesis; yet the creationists have produced not a shred of it so far. Where are the data and age calculations that result in a consistent set of ages for all rocks on earth, as well as those from the moon and the meteorites, no greater than 10 000 years? Glaringly absent, it seems.
Second, it is an approach doomed to failure at the outset. Creationists seem to think that a few examples of incorrect radiometric ages invalidate all of the results of radiometric dating, but such a conclusion is illogical. Even things that work well do not work well all of the time and under all circumstances. Try, for example, wearing a watch that is not waterproof while swimming. It will probably fail, but what would a reasonable person conclude from that? That watches do not work? Hardly.
A few verified examples of incorrect radiometric ages are simply insufficient to prove that radiometric dating is invalid. All they indicate is that the methods are not infallible. Those of us who have developed and used dating techniques to solve scientific problems are well aware that the systems are not perfect; we ourselves have provided numerous examples of instances in which the techniques fail. We often test them under controlled conditions to learn when and why they fail so we will not use them incorrectly. We have even discredited entire techniques. For example, after extensive testing over many years, it was concluded that uranium-helium dating is highly unreliable because the small helium atom diffuses easily out of minerals over geologic time. As a result, this method is not used except in rare and highly specialized applications. Other dating techniques, like K-Ar (potassium-argon and its more recent variant 40Ar/39Ar), Rb-Sr (rubidium-strontium), Sm-Nd (samarium-neodynium), Lu-Hf (lutetium-hafnium), and U-Pb (uranium-lead and its variant Pb-Pb), have all stood the test of time. These methods provide valuable and valid age data in most instances, although there is a small percentage of cases in which even these generally reliable methods yield incorrect results. Such failures may be due to laboratory errors (mistakes happen), unrecognized geologic factors (nature sometimes fools us), or misapplication of the techniques (no one is perfect). In order to accomplish their goal of discrediting radiometric dating, however, creationists are faced with the daunting task of showing that a preponderance of radiometric ages are wrong — that the methods are untrustworthy most of the time. Not only that, they have to show the flaws in those dating studies that provide independent corroborative evidence that radiometric methods work. This is a tall order and the creationists have made no progress so far.
It is rare for a study involving radiometric dating to contain a single determination of age. Usually determinations of age are repeated to avoid laboratory errors, are obtained on more than one rock unit or more than one mineral from a rock unit in order to provide a cross-check, or are evaluated using other geologic information that can be used to test and corroborate the radiometric ages. Scientists who use radiometric dating typically use every means at their disposal to check, recheck, and verify their results, and the more important the results the more they are apt to be checked and rechecked by others. As a result, it is nearly impossible to be completely fooled by a good set of radiometric age data collected as part of a well-designed experiment.
The purpose of this paper is to describe briefly a few typical radiometric dating studies, out of hundreds of possible examples documented in the scientific literature, in which the ages are validated by other available information. I have selected four examples from recent literature, mostly studies involving my work and that of a few close colleagues because it was easy to do so. I could have selected many more examples but then this would have turned into a book rather than the intended short paper.
The Manson Meteorite Impact and the Pierre Shale
In the Cretaceous Period, a large meteorite struck the earth at a location near the present town of Manson, Iowa. The heat of the impact melted some of the feldspar crystals in the granitic rocks of the impact zone, thereby resetting their internal radiometric clocks. These melted crystals, and therefore the impact, have been dated by the 40Ar/39Ar method at 74.1 Ma (million years; Izett and others 1998), but that is not the whole story by a long shot. The impact also created shocked quartz crystals that were blasted into the air and subsequently fell to the west into the inland sea that occupied much of central North America at that time. Today this shocked quartz is found in South Dakota, Colorado, and Nebraska in a thin layer (the Crow Creek Member) within a thick rock formation known as the Pierre Shale. The Pierre Shale, which is divided into identifiable sedimentary beds called members, also contains abundant fossils of numerous species of ammonites, ancestors of the chambered nautilus. The fossils, when combined with geologic mapping, allow the various exposed sections of the Pierre Shale to be pieced together in their proper relative positions to form a complete composite section (Figure 1). The Pierre Shale also contains volcanic ash that was erupted from volcanoes and then fell into the sea, where it was preserved as thin beds. These ash beds, called bentonites, contain sanidine feldspar and biotite that has been dated using the 40Ar/39Ar technique.
Figure 1
The results of the Manson Impact/Pierre Shale dating study (Izett and others 1998) are shown in Figure 1. There are three important things to note about these results. First, each age is based on numerous measurements; laboratory errors, had there been any, would be readily apparent. Second, ages were measured on two very different minerals, sanidine and biotite, from several of the ash beds. The largest difference between these mineral pairs, in the ash from the Gregory Member, is less than 1%. Third, the radiometric ages agree, within analytical error, with the relative positions of the dated ash beds as determined by the geologic mapping and the fossil assemblages; that is, the ages get older from top to bottom as they should. Finally, the inferred age of the shocked quartz, as determined from the age of the melted feldspar in the Manson impact structure (74.1 ± 0.1 Ma), is in very good agreement with the ages of the ash beds above and below it. How could all of this be so if the 40Ar/39Ar dating technique did not work?
The Ages of Meteorites
Meteorites, most of which are fragments of asteroids, are very interesting objects to study because they provide important evidence about the age, composition, and history of the early solar system. There are many types of meteorites. Some are from primitive asteroids whose material is little modified since they formed from the early solar nebula. Others are from larger asteroids that got hot enough to melt and send lava flows to the surface. A few are even from the Moon and Mars. The most primitive type of meteorites are called chondrites, because they contain little spheres of olivine crystals known as chondrules. Because of their importance, meteorites have been extensively dated radiometrically; the vast majority appear to be 4.4–4.6 Ga (billion years) old. Some meteorites, because of their mineralogy, can be dated by more than one radiometric dating technique, which provides scientists with a powerful check of the validity of the results. The results from three meteorites are shown in Table 1. Many more, plus a discussion of the different types of meteorites and their origins, can be found in Dalrymple (1991).
Table 1
There are 3 important things to know about the ages in Table 1. The first is that each meteorite was dated by more than one laboratory — Allende by 2 laboratories, Guarena by 2 laboratories, and St Severin by four laboratories. This pretty much eliminates any significant laboratory biases or any major analytical mistakes. The second thing is that some of the results have been repeated using the same technique, which is another check against analytical errors. The third is that all three meteorites were dated by more than one method — two methods each for Allende and Guarena, and four methods for St Severin. This is extremely powerful verification of the validity of both the theory and practice of radiometric dating. In the case of St Severin, for example, we have 4 different natural clocks (actually 5, for the Pb-Pb method involves 2 different radioactive uranium isotopes), each running at a different rate and each using elements that respond to chemical and physical conditions in much different ways. And yet, they all give the same result to within a few percent. Is this a remarkable coincidence? Scientists have concluded that it is not; it is instead a consequence of the fact that radiometric dating actually works and works quite well. Creationists who wants to dispute the conclusion that primitive meteorites, and therefore the solar system, are about 4.5 Ga old certainly have their work cut out for them!
The K-T Tektites
One of the most exciting and important scientific findings in decades was the 1980 discovery that a large asteroid, about 10 kilometers diameter, struck the earth at the end of the Cretaceous Period. The collision threw many tons of debris into the atmosphere and possibly led to the extinction of the dinosaurs and many other life forms. The fallout from this enormous impact, including shocked quartz and high concentrations of the element iridium, has been found in sedimentary rocks at more than 100 locations worldwide at the precise stratigraphic location of the Cretaceous-Tertiary (K-T) boundary (Alvarez and Asaro 1990; Alvarez 1998). We now know that the impact site is located on the Yucatan Peninsula. Measuring the age of this impact event independently of the stratigraphic evidence is an obvious test for radiometric methods, and a number of scientists in laboratories around the world set to work.
Table 2
In addition to shocked quartz grains and high concentrations of iridium, the K-T impact produced tektites, which are small glass spherules that form from rock that is instantaneously melted by a large impact. The K-T tektites were ejected into the atmosphere and deposited some distance away. Tektites are easily recognizable and form in no other way, so the discovery of a sedimentary bed (the Beloc Formation) in Haiti that contained tektites and that, from fossil evidence, coincided with the K-T boundary provided an obvious candidate for dating. Scientists from the US Geological Survey were the first to obtain radiometric ages for the tektites and laboratories in Berkeley, Stanford, Canada, and France soon followed suit. The results from all of the laboratories were remarkably consistent with the measured ages ranging only from 64.4 to 65.1 Ma (Table 2). Similar tektites were also found in Mexico, and the Berkeley lab found that they were the same age as the Haiti tektites. But the story doesn’t end there.
The K-T boundary is recorded in numerous sedimentary beds around the world. The Z-coal, the Ferris coal, and the Nevis coal in Montana and Saskatchewan all occur immediately above the K-T boundary. Numerous thin beds of volcanic ash occur within these coals just centimeters above the K-T boundary, and some of these ash beds contain minerals that can be dated radiometrically. Ash beds from each of these coals have been dated by 40Ar/39Ar, K-Ar, Rb-Sr, and U-Pb methods in several laboratories in the US and Canada. Since both the ash beds and the tektites occur either at or very near the K-T boundary, as determined by diagnostic fossils, the tektites and the ash beds should be very nearly the same age, and they are (Table 2).
There are several important things to note about these results. First, the Cretaceous and Tertiary periods were defined by geologists in the early 1800s. The boundary between these periods (the K-T boundary) is marked by an abrupt change in fossils found in sedimentary rocks worldwide. Its exact location in the stratigraphic column at any locality has nothing to do with radiometric dating — it is located by careful study of the fossils and the rocks that contain them, and nothing more. Second, the radiometric age measurements, 187 of them, were made on 3 different minerals and on glass by 3 distinctly different dating methods (K-Ar and 40Ar/39Ar are technical variations that use the same parent-daughter decay scheme), each involving different elements with different half-lives. Furthermore, the dating was done in 6 different laboratories and the materials were collected from 5 different locations in the Western Hemisphere. And yet the results are the same within analytical error. If radiometric dating didn’t work then such beautifully consistent results would not be possible.
Dating of The Mt Vesuvius Eruption
In the early afternoon of August 24, 79 CE, Mt Vesuvius erupted violently, sending hot ash flows speeding down its flanks. These flows buried and destroyed Pompeii and other nearby Roman cities. We know the exact day of this eruption because Pliny the Younger carefully recorded the event. In 1997 a team of scientists from the Berkeley Geochronology Center and the University of Naples decided to see if the 40Ar/39Ar method of radiometric dating could accurately measure the age of this very young (by geological standards) volcanic material. They separated sanidine crystals from a sample of one of the ash flows. Incremental heating experiments on 12 samples of sanidine yielded 46 data points that resulted in an isochron age of 1925 94 years. The actual age of the flow in 1997 was 1918 years. Is this just a coincidence? No — it is the result of extremely careful analyses using a technique that works.
This is not the only dating study to be done on an historic lava flow. Two extensive studies done more than 25 years ago involved analyzing the isotopic composition of argon in such flows to determine if the source of the argon was atmospheric, as must be assumed in K-Ar dating (Dalrymple 1969, 26 flows; Krummenacher 1970, 19 flows). Both studies detected, in a few of the flows, deviations from atmospheric isotopic composition, most often in the form of excess 40Ar. The majority of flows, however, had no detectable excess 40Ar and thus gave correct ages as expected. Of the handful of flows that did contain excess 40Ar, only a few did so in significant amounts. The 122 BCE flow from Mt Etna, for example, gave an erroneous age of 0.25 0.08 Ma. Note, however, that even an error of 0.25 Ma would be insignificant in a 20 Ma flow with equivalent potassium content. Austin (1996) has documented excess 40Ar in the 1986 dacite flow from Mount St Helens, but the amounts are insufficient to produce significant errors in all but the youngest rocks.
The 79 CE Mt Vesuvius flow, the dating of which is described above, also contained excess 40Ar. The 40Ar/39Ar isochron method used by the Berkeley scientists, however, does not require any assumptions about the composition of the argon trapped in the rock when it formed — it may be atmospheric or any other composition for that matter. Thus any potential error due to excess 40Ar was eliminated by the use of this technique, which was not available when the studies by Dalrymple (1969) and Krummenacher (1970) were done.
Thus the large majority of historic lava flows that have been studied either give correct ages, as expected, or have quantities of excess radiogenic 40Ar that would be insignificant in all but the youngest rocks. The 40Ar/39Ar technique, which is now used instead of K-Ar methods for most studies, has the capability of automatically detecting, and in many instances correcting for, the presence of excess 40Ar, should it be present.
Summary
In this short paper I have briefly described 4 examples of radiometric dating studies where there is both internal and independent evidence that the results have yielded valid ages for significant geologic events. It is these studies, and the many more like them documented in the scientific literature, that the creationists need to address before they can discredit radiometric dating. Their odds of success are near zero. Even if against all odds they should succeed, it still would not prove that the Earth is young. Only when young-earth creationists produce convincing quantitative, scientific evidence that the earth is young will they be worth listening to on this important scientific matter.
Acknowledgments
I thank Chris Stassen and 2 anonymous reviewers for their thoughtful comments, which led to important improvements in the manuscript.
References
Alvarez W. T Rex and the Crater of Doom. Vintage Books, 1998.
Alvarez W, Asaro, F. An extraterrestrial impact. Scientific American 1990; 263 (4): 78–84.
Arndts R, Overn W. Isochrons. Bible-Science Newsletter 1981; 14 (4): 5–6.
Austin SA. Excess argon within mineral concentrates from the new dacite lava dome at Mount St Helens volcano. Creation Ex Nihlo Techncal Journal 1996; 10: 335–43.
Dalrymple GB. 40Ar/36Ar analyses of historic lava flows. Earth and Planetary Science Letters 1969; 6: 47–55.
Dalrymple GB. How old is the earth? A reply to scientific creationism. In: Awbrey F, Thwaites WM, editors. Evolutionists Confront Creationists, Proceedings of the 63rd Annual Meeting, Pacific Division, American Association for the Advancement of Science, vol 1, part 3. 1984. p 66–131.
Dalrymple GB. The Age of the Earth. Stanford, Stanford University Press, 1991.
Dalrymple GB, Izett GA, Snee LW, Obradovich JD. 40Ar/39Ar age spectra and total-fusion ages of tektites from Cretaceous-Tertiary boundary sedimentary rocks in the Beloc formation, Haiti. US Geological Survey Bulletin 2065. 1993.
Gill CH. A sufficient reason for false Rb-Sr isochrons. Creation Research Society Quarterly 1996; 33: 105–8.
Izett GA, Cobban WA, Dalrymple GB, Obradovich JD. 40Ar/39Ar age of the Manson impact structure, Iowa, and correlative impact ejecta in the Crow Creek Member of the Pierra Shale (Upper Cretaceous), South Dakota and Nebraska. Geological Society of America Bulletin 1998; 110: 361–76.
Krummenacher D. Isotopic composition of argon in modern surface volcanic rocks. Earth and Planetary Science Letters 8: 109–17.
Morris HM. Scientific Creationism. 2nd ed. San Diego (CA): Creation-Life Publishing, 1985.
Morris JD. The Young Earth. Colorado Springs (CO):Creation-Life Books, 1994.
Renne PR, Sharp WD, Deino AL, Orsi G, Civetta L. 40Ar/39Ar dating into the historical realm: Calibration against Pliny the Younger. Science, 1997; 277: 1279–80.
Rugg S, Austin SA. Evidence for rapid formation and failure of Pleistocene “lava dams” of the western Grand Canyon, Arizona. In: Walsh RE, editor. Proceedings of the Fourth International Conference on Creationism Pittsburgh: Creation Science Fellowship, 1998. p 475–86.
York D. In Search of Lost Time. Bristol (UK): Institute of Physics Publishing, 1997.
York D, Dalrymple, GB. Comments on a creationist’s irrelevant discussion of isochrons. Reports of the National Center for Science Education 2000; 20 (3): xx–xx.
Woodmorappe J. Radiometric geochronology reappraised. Creation Research Society Quarterly 1979; 16: 102–29, 147.
The Evolution Debate is About Honesty
[James A Haught, editor of the Charleston (West Virginia) Gazette, was awarded a Clarion Award by the Association of Women in Communications in the category of editorial opinion in US newspapers under 100 000 circulation. Haught's editorials and columns defended the separation of church and state in a variety of ways, including outspoken opposition to recent attempts of creationists to have the Kanawha County school board advise teachers to teach the supposed evidence against evolution (see Karl D Fezer, "Juicy Fruit or Spearmint in West Virginia", RNCSE 2000; 20 [1-2]: 16-19). RNCSE is pleased to reprint one of the columns for which Haught received his well-deserved award.]
During a recent evolution showdown, a visiting "creation scientist" from California repeatedly challenged me to debate, because I support the teaching of evolution. A Charleston talk radio host blistered me on the air because I would not come on his show and quarrel with the creationist professor.
But I felt it would be silly for me to argue about his supernatural beliefs. After all, I would not debate a Scientologist who asserts that all human souls are "thetans" from another planet. And I would not quarrel with a Unification Church member's claim that Jesus appeared to Master Moon and told him to convert all people as "Moonies". And I would not dispute a Mormon's belief that Jesus visited prehistoric America. And so on, and so on.
Let them all believe whatever they want. It is pointless to go on radio shows and wrangle over mystical claims. However, such claims must not be imposed on captive children in government-owned schools. That is prohibited by the separation of church and state, a core principle in the First Amendment in America's Bill of Rights.
America's time-tested freedom of religion means that every group may worship however it wishes in its own private church, but it cannot use the power of government to push its beliefs on others. Therefore it was gratifying that the Kanawha County school board overwhelmingly rejected a proposal to let creationist teachers denounce evolution in class. Educated families owe thanks to 4 brave board members - Pete Thaw, Bill Raglin, Cheryle Hall and John Luoni - who withstood heavy pressure from a throng of fundamentalists.
To me, the whole issue hinges on honesty. Let me explain: Science, from a Latin word meaning knowledge, is simply a search for trustworthy facts. It is human intelligence at work. The process is honest, because every researcher's claim is challenged by other researchers. They test and retest by many methods, until a new idea fails or holds firm. (A researcher who falsifies data is a loathsome criminal in the eyes of fellow scientists.)
While some individual scientists are pig-headed, an entire field cannot be. Science goes where the evidence leads. Science is honest enough to admit mistakes. When new evidence shatters a previous assertion, the old belief is dropped or modified. No such setbacks have hit the theory of evolution.
After 140 years of research, virtually the entire scientific world now agrees that evolution is a fundamental aspect of nature. Complex animals and plants arose from earlier, simpler ones, over hundreds of millions of years. The fossil record shows it. Geological strata show it. Radioactive dating shows it. The incredible diversity of species, with variations in different locales, shows it. The uncanny similarity of organs, bones, fluids, and nerves in many animals shows it.
Evolution was proved when skimpy Indian maize was improved into today's nutritious corn. It was proved when drug-resistant bacteria grew from survivors of antibiotic treatment (survival of the fittest). ... It was proved by the clear fossil record that today's horse grew from a tiny precursor.
College biology books are filled with many more examples. All this is why evolution should be taught in public school classes along with astronomy, physics, chemistry, and other established sciences. However, a fringe of "creation scientists" - rigid religious zealots - contend that evolution never happened, because they think it disagrees with their literal reading of the Book of Genesis. These people are not objective about evidence: they reject anything that supports evolution and exaggerate anything that might concur with the Old Testament.
The visitor who challenged me to debate holds a doctorate in physical education and is listed as "an adjunct professor of physiology for the Institute for Creation Research" at Santee, California. He implied that he's motivated only by scientific interest - but his group's Web site is that of a church. It proclaims:
Well, all this is standard fundamentalism - but it is not science, and it would be illegal to teach it in public-school science classes, especially in cosmopolitan Charleston schools containing Muslim, Jewish, Hindu, Buddhist, and Baha'i children. Maybe you can see why I chose not to debate this mentality. Incidentally, the visiting professor offered $250 000 to anyone who can prove evolution. If this column wins the reward, I'll donate it to a real science institute.
[Reprinted from the Charleston Gazette, December 21, 1999, by permission.]
During a recent evolution showdown, a visiting "creation scientist" from California repeatedly challenged me to debate, because I support the teaching of evolution. A Charleston talk radio host blistered me on the air because I would not come on his show and quarrel with the creationist professor.
But I felt it would be silly for me to argue about his supernatural beliefs. After all, I would not debate a Scientologist who asserts that all human souls are "thetans" from another planet. And I would not quarrel with a Unification Church member's claim that Jesus appeared to Master Moon and told him to convert all people as "Moonies". And I would not dispute a Mormon's belief that Jesus visited prehistoric America. And so on, and so on.
Let them all believe whatever they want. It is pointless to go on radio shows and wrangle over mystical claims. However, such claims must not be imposed on captive children in government-owned schools. That is prohibited by the separation of church and state, a core principle in the First Amendment in America's Bill of Rights.
America's time-tested freedom of religion means that every group may worship however it wishes in its own private church, but it cannot use the power of government to push its beliefs on others. Therefore it was gratifying that the Kanawha County school board overwhelmingly rejected a proposal to let creationist teachers denounce evolution in class. Educated families owe thanks to 4 brave board members - Pete Thaw, Bill Raglin, Cheryle Hall and John Luoni - who withstood heavy pressure from a throng of fundamentalists.
To me, the whole issue hinges on honesty. Let me explain: Science, from a Latin word meaning knowledge, is simply a search for trustworthy facts. It is human intelligence at work. The process is honest, because every researcher's claim is challenged by other researchers. They test and retest by many methods, until a new idea fails or holds firm. (A researcher who falsifies data is a loathsome criminal in the eyes of fellow scientists.)
While some individual scientists are pig-headed, an entire field cannot be. Science goes where the evidence leads. Science is honest enough to admit mistakes. When new evidence shatters a previous assertion, the old belief is dropped or modified. No such setbacks have hit the theory of evolution.
After 140 years of research, virtually the entire scientific world now agrees that evolution is a fundamental aspect of nature. Complex animals and plants arose from earlier, simpler ones, over hundreds of millions of years. The fossil record shows it. Geological strata show it. Radioactive dating shows it. The incredible diversity of species, with variations in different locales, shows it. The uncanny similarity of organs, bones, fluids, and nerves in many animals shows it.
Evolution was proved when skimpy Indian maize was improved into today's nutritious corn. It was proved when drug-resistant bacteria grew from survivors of antibiotic treatment (survival of the fittest). ... It was proved by the clear fossil record that today's horse grew from a tiny precursor.
College biology books are filled with many more examples. All this is why evolution should be taught in public school classes along with astronomy, physics, chemistry, and other established sciences. However, a fringe of "creation scientists" - rigid religious zealots - contend that evolution never happened, because they think it disagrees with their literal reading of the Book of Genesis. These people are not objective about evidence: they reject anything that supports evolution and exaggerate anything that might concur with the Old Testament.
The visitor who challenged me to debate holds a doctorate in physical education and is listed as "an adjunct professor of physiology for the Institute for Creation Research" at Santee, California. He implied that he's motivated only by scientific interest - but his group's Web site
We believe God has raised up ICR to spearhead Biblical Christianity's defense against the godless dogma of evolutionary humanism. ... ICR is funded by God's people ... to proclaim God's truth about origins.The Institute for Creation Research calls itself "a Christ-focused creation ministry". It says humans were made fully developed "in the 6 literal days of the creation week described in Genesis". It says this was a "relatively recent" event, and that fossils were formed during Noah's flood. It says anyone not saved "solely" by Jesus will "be consigned to the everlasting fire prepared for the devil and his angels". In other words, a billion Muslims, a billion Hindus, and hundreds of millions of Buddhists, Jews, Baha'is, Shintoists, and so on are doomed to fry forever, according to the ICR.
Well, all this is standard fundamentalism - but it is not science, and it would be illegal to teach it in public-school science classes, especially in cosmopolitan Charleston schools containing Muslim, Jewish, Hindu, Buddhist, and Baha'i children. Maybe you can see why I chose not to debate this mentality. Incidentally, the visiting professor offered $250 000 to anyone who can prove evolution. If this column wins the reward, I'll donate it to a real science institute.
[Reprinted from the Charleston Gazette, December 21, 1999, by permission.]
Review: Ride to Glory
As a matter of principle, I finish any book I start reading. Some books are easy to finish - anything by John Irving, and John Kennedy Toole's masterpiece A Confederacy of Dunces, for example. Others are more difficult. No book in recent memory, or distant memory for that matter, challenged this principle more than Ride to Glory by Warren LeRoi Johns, a lawyer and novelist wannabe.
Ride to Glory tells the story of one Joshua Chamberlain Ryan, a double PhD candidate in geology and paleontology, who has come to the conclusion, through a careful analysis of the evidence, that the earth is no more than 10 000 years old and that descent with modification is not a valid scientific theory, but rather a collection of "horse-and-buggy myths". Throughout the book Josh continually spouts standard young-earth creationist claptrap, and in fact, many of Johns's source for Josh's diatribes are well-known creationist organizations such as the Institute for Creation Research and anti-evolutionist authors such as Michael Denton.
The plot revolves around a mock trial in which the jury is asked to "render a simple Yes or No verdict to this key issue: 'Is evolution a fact?'"; the judge adds, "Your responsibility will be to judge Charles Robert Darwin guilty or not guilty of propagating fact-free science" (italics in original). The trial is staged by ace Hollywood promoter Pace Terhune. Josh is the star witness, aided by his best friend, law student JT Thomas. JT tosses fluff-ball questions at Josh, whose creationist rhetoric flows in italics, meticulously footnoted by Johns. Traci Kilburn, the new and beautiful love in Josh's life, is responsible for the completely unchallenging cross-examination.
The book fails as literature even more than it fails as science. The dialog is so contrived that it quickly became close to physically painful to read. Josh is described by one of his professors as speaking "the language of the streets". Apparently Johns has not heard any "language of the streets" since "blaxploitation" films were big in the 1970s. Much of the dialog strains at wit and then gets sprinkled with some "bros" to add that hip young attitude: "What's goin' on, Bro? You and the Montgomery County Sheriff are the only people cruisin' the scene at this outrageous hour. You oughta' be in church with the rest of the sinners... [Y]ou could use some of your granddad's preachin' to rid you of those lawyer-like flaws." Who in the world talks like that? Johns must have worn out the apostrophe on his keyboard.
The characters in the book are all completely 2-dimensional, without the slightest bit of the complexity and depth that draws us to literary characters. Joshua Chamberlain Ryan has a 4.0 grade-point average, and never a doubt about his convictions or beliefs enters his mind. Traci Kilburn and JT Thomas are unfailingly witty and charming. Dr Karl Striker, "flamboyant campus scientist" and Josh's archnemesis, comes across as gruff, authoritarian and, most importantly, unbending in his religiously dogmatic approach to Darwinism. In fact, the contrast between the supporters of evolution, Striker and his minions, and the upholders of truth, Josh and his buddies, is shallow and obvious to the point of boredom. Two of Striker's underlings turn out to be pathetically nefarious characters, a drug addict and a would-be murderer who attempts to kill Josh.
Josh Ryan appears virtually faultless, which makes him unreal and not the least bit sympathetic. Likewise, Traci and JT are cut from exactly the same mold, always equipped with snappy little comebacks for any situation. When we read about fictional characters, it is often more their faults than their superlative virtues that draw us to them, because we can relate to fallible characters - except for readers who happen to be perfect themselves; but I would imagine that that clientele is pretty small.
The plot is so predictable that I began wishing I had taken some speed reading courses. The reader is pummeled, page after page, with tiresome, strained dialog, and such an easily predictable plot that it is possible to anticipate the story line 10, or even 100, pages later. Each plot line proceeds mechanically and unswervingly so that the story wraps up at the end like a television sitcom.
There is not space here to go into the plot in any depth, but I feel pretty sure that after the first 50 pages or so any reader can guess how just about the whole thing will turn out. Traci will accept Josh's proposal of marriage; Josh will be united with his grandmother, although she dies trying to save his thoroughbred horse from a barn fire set by one of Striker's minions (who then dies in a minivan trying to escape the scene); Josh becomes a star after thoroughly refuting Darwin's theories in "Monkey II"; and JT is promised a spot at a major law firm upon his graduation from law school.
Though subtitled An American Novel, from my experience studying the former Soviet Union in depth, I would say that the book reads more like some kind of official propaganda. The absolute demarcation between the guys wearing the white hats and the guys wearing the black hats, and the complete lack of human conflict on any true level, drag the book to such a shallow level that it quickly runs aground; just getting to the end is a real chore.
By now you probably have the idea that I am not going to recommend that you rush right out and buy Ride to Glory, but if you do want to check out the story for yourself, I recommend just getting a copy of Jack Chick's notorious anti-evolution tract, Big Daddy. It could have easily served as Johns's first draft.
Ride to Glory tells the story of one Joshua Chamberlain Ryan, a double PhD candidate in geology and paleontology, who has come to the conclusion, through a careful analysis of the evidence, that the earth is no more than 10 000 years old and that descent with modification is not a valid scientific theory, but rather a collection of "horse-and-buggy myths". Throughout the book Josh continually spouts standard young-earth creationist claptrap, and in fact, many of Johns's source for Josh's diatribes are well-known creationist organizations such as the Institute for Creation Research and anti-evolutionist authors such as Michael Denton.
The plot revolves around a mock trial in which the jury is asked to "render a simple Yes or No verdict to this key issue: 'Is evolution a fact?'"; the judge adds, "Your responsibility will be to judge Charles Robert Darwin guilty or not guilty of propagating fact-free science" (italics in original). The trial is staged by ace Hollywood promoter Pace Terhune. Josh is the star witness, aided by his best friend, law student JT Thomas. JT tosses fluff-ball questions at Josh, whose creationist rhetoric flows in italics, meticulously footnoted by Johns. Traci Kilburn, the new and beautiful love in Josh's life, is responsible for the completely unchallenging cross-examination.
The book fails as literature even more than it fails as science. The dialog is so contrived that it quickly became close to physically painful to read. Josh is described by one of his professors as speaking "the language of the streets". Apparently Johns has not heard any "language of the streets" since "blaxploitation" films were big in the 1970s. Much of the dialog strains at wit and then gets sprinkled with some "bros" to add that hip young attitude: "What's goin' on, Bro? You and the Montgomery County Sheriff are the only people cruisin' the scene at this outrageous hour. You oughta' be in church with the rest of the sinners... [Y]ou could use some of your granddad's preachin' to rid you of those lawyer-like flaws." Who in the world talks like that? Johns must have worn out the apostrophe on his keyboard.
The characters in the book are all completely 2-dimensional, without the slightest bit of the complexity and depth that draws us to literary characters. Joshua Chamberlain Ryan has a 4.0 grade-point average, and never a doubt about his convictions or beliefs enters his mind. Traci Kilburn and JT Thomas are unfailingly witty and charming. Dr Karl Striker, "flamboyant campus scientist" and Josh's archnemesis, comes across as gruff, authoritarian and, most importantly, unbending in his religiously dogmatic approach to Darwinism. In fact, the contrast between the supporters of evolution, Striker and his minions, and the upholders of truth, Josh and his buddies, is shallow and obvious to the point of boredom. Two of Striker's underlings turn out to be pathetically nefarious characters, a drug addict and a would-be murderer who attempts to kill Josh.
Josh Ryan appears virtually faultless, which makes him unreal and not the least bit sympathetic. Likewise, Traci and JT are cut from exactly the same mold, always equipped with snappy little comebacks for any situation. When we read about fictional characters, it is often more their faults than their superlative virtues that draw us to them, because we can relate to fallible characters - except for readers who happen to be perfect themselves; but I would imagine that that clientele is pretty small.
The plot is so predictable that I began wishing I had taken some speed reading courses. The reader is pummeled, page after page, with tiresome, strained dialog, and such an easily predictable plot that it is possible to anticipate the story line 10, or even 100, pages later. Each plot line proceeds mechanically and unswervingly so that the story wraps up at the end like a television sitcom.
There is not space here to go into the plot in any depth, but I feel pretty sure that after the first 50 pages or so any reader can guess how just about the whole thing will turn out. Traci will accept Josh's proposal of marriage; Josh will be united with his grandmother, although she dies trying to save his thoroughbred horse from a barn fire set by one of Striker's minions (who then dies in a minivan trying to escape the scene); Josh becomes a star after thoroughly refuting Darwin's theories in "Monkey II"; and JT is promised a spot at a major law firm upon his graduation from law school.
Though subtitled An American Novel, from my experience studying the former Soviet Union in depth, I would say that the book reads more like some kind of official propaganda. The absolute demarcation between the guys wearing the white hats and the guys wearing the black hats, and the complete lack of human conflict on any true level, drag the book to such a shallow level that it quickly runs aground; just getting to the end is a real chore.
By now you probably have the idea that I am not going to recommend that you rush right out and buy Ride to Glory, but if you do want to check out the story for yourself, I recommend just getting a copy of Jack Chick's notorious anti-evolution tract, Big Daddy. It could have easily served as Johns's first draft.
Review: Evolution
In 1981, paleontologist Colin Patterson spoke at the American Museum of Natural History. Later he said that in his talk, "I put a case for [the] difficulties and problems with evolution, specifically in the field of systematics. I was too naïve and foolish to guess what might happen: the talk was taped by a creationist who passed the tape to [creationist] Luther Sunderland. ...I was putting a case for discussion, as I thought off the record, and was speaking only about systematics, a specialised field" (Fezer 1984: 5).
Snippets from this unauthorized taping (for which no authorized transcript exists; see Strahler 1987) have been making the rounds of anti-evolutionist publications since Luther Sunderland and Gary Parker's 1982 Impact article. They have popped up in many subsequent issues of ICR's Impact (for example, Buckna and Laidlaw 1996) and routinely appear in anti-evolutionist articles and web sites (for example, Lenard 2000). Patterson was also featured in a 1996 article in the journal Origins and Design (Nelson 1996), a venue devoted to "intelligent design theory", which included 9 of his quotations that supposedly manifest what Nelson calls Patterson's "agnosticism about evolution".
Fast forward to 1999; if ever he was, Patterson is agnostic about evolution no more. All opportunities for anti-evolutionist innuendo and misstatements are put to rest in the second edition of Evolution. Sadly, Patterson died 3 days after delivering the manuscript to the publisher; 2 of his colleagues (Peter Forey and James Mallet) did some minor revisions and final editing.
The book is a concise, lucid introduction to evolutionary biology for the layperson. Among the valuable resources is a discussion of molecular biology that contains references to 1996 and so is fairly up to date. The drawings and charts make the text easier for a nonspecialist to follow.
I really appreciated the discussion of hemoglobin. Patterson reports that 550 mutations of human hemoglobin have been described (including substitutions, deletions, and additions), and that 1 human in 2000 carries a mutant hemoglobin. The "Tak" and "Saverne" mutations add 10 amino acids each to the beta hemoglobin chain, while the "McKees Rocks" mutation shortens the same chain by 2 amino acids. This is a powerful argument against the anti-evolutionist mantra of "mutations are bad", because, as Patterson notes, "none inhibits development and most produce no detectable physical symptoms" (p 29).
Patterson also focuses on homology at the molecular level, especially as it applies to the evolution of hemoglobin. There is a good discussion of gene duplication, the relationship of the hemoglobin pseudogenes to the active genes, and some nice gene histories showing hemoglobin relationships among primates and other mammals. Patterson finds Motoo Kimura's neutral theory of evolution quite appealing and returns to it frequently. If one is looking for a pithy comment to counter anti-evolutionist claims, try Patterson's conclusion that "[I]n genetic terms we are hardly more distinct from chimpanzees than are subspecies in other groups of animals" (p 113).
Though an interesting introduction to evolutionary biology, the real strengths of this book are in its final chapters and preface, where Patterson explains his ideas about evolution and comments on creationism and (indirectly) on the 1981 taping of his talk. Clarifying his views on evolution in the preface to the second edition, Patterson says:
Patterson concludes, "[i]n terms of mechanism ... the neutral theory of molecular evolution is a scientific theory; it can be put into law-like form: changes in DNA that are less likely to be subject to natural selection occur more rapidly. This law is tested every time homologous DNA sequences are compared. ... But neutral theory assumes (or includes) [the] truth of the general theory - common ancestry or Darwin's 'descent with modification' - and 'misprints' shared between species, like the pseudogenes or reversed Alu sequences, are (to me) incontrovertible evidence of common descent" (p 119).
Creationism itself receives only a few pages, which include Patterson's response to the taping: "Because creationists lack scientific research to support such theories as a young earth ... a world-wide flood ... or separate ancestry for humans and apes, their common tactic is to attack evolution by hunting out debate or dissent among evolutionary biologists. ... I learned that one should think carefully about candor in argument (in publications, lectures, or correspondence) in case one was furnishing creationist campaigners with ammunition in the form of 'quotable quotes', often taken out of context" (p 122).
Perhaps the best audience for this book would be anti-evolutionists. Not only could they learn about the evidence for evolution at the molecular level, but they might be inspired to correct the inaccuracies about the late Dr Patterson that abound on their web sites.
Snippets from this unauthorized taping (for which no authorized transcript exists; see Strahler 1987) have been making the rounds of anti-evolutionist publications since Luther Sunderland and Gary Parker's 1982 Impact article. They have popped up in many subsequent issues of ICR's Impact (for example, Buckna and Laidlaw 1996) and routinely appear in anti-evolutionist articles and web sites (for example, Lenard 2000). Patterson was also featured in a 1996 article in the journal Origins and Design (Nelson 1996), a venue devoted to "intelligent design theory", which included 9 of his quotations that supposedly manifest what Nelson calls Patterson's "agnosticism about evolution".
Fast forward to 1999; if ever he was, Patterson is agnostic about evolution no more. All opportunities for anti-evolutionist innuendo and misstatements are put to rest in the second edition of Evolution. Sadly, Patterson died 3 days after delivering the manuscript to the publisher; 2 of his colleagues (Peter Forey and James Mallet) did some minor revisions and final editing.
The book is a concise, lucid introduction to evolutionary biology for the layperson. Among the valuable resources is a discussion of molecular biology that contains references to 1996 and so is fairly up to date. The drawings and charts make the text easier for a nonspecialist to follow.
I really appreciated the discussion of hemoglobin. Patterson reports that 550 mutations of human hemoglobin have been described (including substitutions, deletions, and additions), and that 1 human in 2000 carries a mutant hemoglobin. The "Tak" and "Saverne" mutations add 10 amino acids each to the beta hemoglobin chain, while the "McKees Rocks" mutation shortens the same chain by 2 amino acids. This is a powerful argument against the anti-evolutionist mantra of "mutations are bad", because, as Patterson notes, "none inhibits development and most produce no detectable physical symptoms" (p 29).
Patterson also focuses on homology at the molecular level, especially as it applies to the evolution of hemoglobin. There is a good discussion of gene duplication, the relationship of the hemoglobin pseudogenes to the active genes, and some nice gene histories showing hemoglobin relationships among primates and other mammals. Patterson finds Motoo Kimura's neutral theory of evolution quite appealing and returns to it frequently. If one is looking for a pithy comment to counter anti-evolutionist claims, try Patterson's conclusion that "[I]n genetic terms we are hardly more distinct from chimpanzees than are subspecies in other groups of animals" (p 113).
Though an interesting introduction to evolutionary biology, the real strengths of this book are in its final chapters and preface, where Patterson explains his ideas about evolution and comments on creationism and (indirectly) on the 1981 taping of his talk. Clarifying his views on evolution in the preface to the second edition, Patterson says:
The knowledge in my first edition came from education and indoctrination; it was that neo-Darwinism is certainty. The knowledge in this second edition comes more from working things out for myself; it is that evolution is certainty. And part of the ignorance in the first edition concerned the difference between neo-Darwinism and evolution, whereas the ignorance in this edition is of the completeness of neo-Darwinism as an explanation of evolution ... I think that belief [shared ancestry] is now confirmed as completely as anything can be in the historical sciences ... [but] ... I am no longer certain that natural selection is the complete explanation...". (p vii).Although Patterson considers the general theory of evolution ("evolution has occurred") to be a historical theory and hence "by some definitions" not a part of science because it deals with unrepeatable events, he acknowledges that it does have rules, does make general predictions, and is open to disproof. Furthermore, evolution has survived a series of severe tests unimaginable to Darwin - including its consistency with genetics, the universality of DNA, and "the evidence from DNA sequences of innumerable 'vestigial organs' at the molecular level" (p 117).
Patterson concludes, "[i]n terms of mechanism ... the neutral theory of molecular evolution is a scientific theory; it can be put into law-like form: changes in DNA that are less likely to be subject to natural selection occur more rapidly. This law is tested every time homologous DNA sequences are compared. ... But neutral theory assumes (or includes) [the] truth of the general theory - common ancestry or Darwin's 'descent with modification' - and 'misprints' shared between species, like the pseudogenes or reversed Alu sequences, are (to me) incontrovertible evidence of common descent" (p 119).
Creationism itself receives only a few pages, which include Patterson's response to the taping: "Because creationists lack scientific research to support such theories as a young earth ... a world-wide flood ... or separate ancestry for humans and apes, their common tactic is to attack evolution by hunting out debate or dissent among evolutionary biologists. ... I learned that one should think carefully about candor in argument (in publications, lectures, or correspondence) in case one was furnishing creationist campaigners with ammunition in the form of 'quotable quotes', often taken out of context" (p 122).
Perhaps the best audience for this book would be anti-evolutionists. Not only could they learn about the evidence for evolution at the molecular level, but they might be inspired to correct the inaccuracies about the late Dr Patterson that abound on their web sites.
References
Buckna D, Laidlaw D. Should evolution be immune from critical analysis in the science classroom? ICR Impact 1996; 282: i-iv.Fezer K. Harper's comforts creationists. Creation/Evolution Newsletter 1984 Nov-Dec; 4 (6): 4-5.
Lenard R. Evolution is not science. 2000; available from
Nelson P. Colin Patterson revisits his famous question about evolution. Origins and Design 1996; 17 (1): 5-8.
Strahler A. Science and Earth History. Buffalo (NY): Prometheus Books, 1987.
Sunderland L, Parker G. Evolution? Prominent scientist reconsiders. ICR Impact 1982; 108: i-iv.
RNCSE 20 (4)
Articles available online are listed below.
Intelligent Design in Pratt County, Kansas
Immediately after the Kansas State Board of Education's August 1999 adoption of science content standards that opened the door to teaching creationism (RNCSE 1999; 19 [3]: 6, 19 [4]: 7-9), speculation began about which local schools would walk through that doorway. Within a few weeks, NCSE heard that in Pratt County, Kansas, local activists were pressing for adoption of the "intelligent design" textbook Of Pandas and People (RNCSE 1999; 19 [4]: 5). Parents in the district contacted NCSE, and, with help from NCSE staff and Kansas Citizens for Science, provided teachers and administrators with extensive information about the flaws of the book. Even though some local school board members were sympathetic to teaching "intelligent design", Pandas was not adopted. But Pratt County's creationists were undaunted.
When the effort to adopt Pandas in Pratt County failed, local school board members began discussing whether to add discussions of "ID theory" to draft curriculum guidelines developed by local teachers. Opinion on the board was divided, and months passed as the document circulated back and forth among a curriculum committee, the board, and high-school science teachers. At one point, the teachers, determined to teach good science, responded to the board's concerns by suggesting that students could write ungraded research papers expressing their opinions of evolution. However, observers of Pratt's school board meetings told NCSE that some members said that the State Board of Education had given them a mandate to teach "intelligent design". The Superintendent of Education was instructed to continue a "dialog" with teachers, and activists pressed the issue in the local newspaper (see "Misquoted Scientists Speak Out"; archived articles at http://www.pratttribune.com contain interesting reading, including many letters to the editor from other parts of the state).
On November 7, three new, pro-evolution candidates were elected to the state Board of Education, making the majority of the board pro-evolution; the new members promised that evolution would be restored to state science standards (Kansas City Star, November 14, 2000). With a disappearing "mandate", ID supporters were under increased pressure to act. On November 27, the Pratt County school board voted 4-2 (with one member absent) to adopt standards requiring students to "know ... [t]here are different scientific perspectives regarding the prevailing textbook evidence used to support the theory of evolution" (Pratt Tribune, November 28, 2000). As rewritten by the board, the curriculum called for using resources frequently recommended by "intelligent design" proponents in the classroom.
Observers told NCSE that local board members who opposed the changes asked whether advice had been sought from the school district's attorney and the state regents (who administer statewide assessments), and were told that no such action had been taken. After the vote, board president Bruce Pinkall told the Kansas City Star, "I'm more concerned with the effect on the staff and the perception of their work and the lack of support from the board for their work."
District parents have contacted the Kansas affiliate of the American Civil Liberties Union to explore the possibility of suing the district. Others have told NCSE that they hope to change the composition of the board in spring 2001, and then bring the district curriculum into harmony with revised state science standards. NCSE will keep its members informed of new developments.
[NCSE thanks Brad Williamson and Liz Craig for information used in this article.]
When the effort to adopt Pandas in Pratt County failed, local school board members began discussing whether to add discussions of "ID theory" to draft curriculum guidelines developed by local teachers. Opinion on the board was divided, and months passed as the document circulated back and forth among a curriculum committee, the board, and high-school science teachers. At one point, the teachers, determined to teach good science, responded to the board's concerns by suggesting that students could write ungraded research papers expressing their opinions of evolution. However, observers of Pratt's school board meetings told NCSE that some members said that the State Board of Education had given them a mandate to teach "intelligent design". The Superintendent of Education was instructed to continue a "dialog" with teachers, and activists pressed the issue in the local newspaper (see "Misquoted Scientists Speak Out"; archived articles at http://www.pratttribune.com contain interesting reading, including many letters to the editor from other parts of the state).
On November 7, three new, pro-evolution candidates were elected to the state Board of Education, making the majority of the board pro-evolution; the new members promised that evolution would be restored to state science standards (Kansas City Star, November 14, 2000). With a disappearing "mandate", ID supporters were under increased pressure to act. On November 27, the Pratt County school board voted 4-2 (with one member absent) to adopt standards requiring students to "know ... [t]here are different scientific perspectives regarding the prevailing textbook evidence used to support the theory of evolution" (Pratt Tribune, November 28, 2000). As rewritten by the board, the curriculum called for using resources frequently recommended by "intelligent design" proponents in the classroom.
Observers told NCSE that local board members who opposed the changes asked whether advice had been sought from the school district's attorney and the state regents (who administer statewide assessments), and were told that no such action had been taken. After the vote, board president Bruce Pinkall told the Kansas City Star, "I'm more concerned with the effect on the staff and the perception of their work and the lack of support from the board for their work."
District parents have contacted the Kansas affiliate of the American Civil Liberties Union to explore the possibility of suing the district. Others have told NCSE that they hope to change the composition of the board in spring 2001, and then bring the district curriculum into harmony with revised state science standards. NCSE will keep its members informed of new developments.
[NCSE thanks Brad Williamson and Liz Craig for information used in this article.]
Baylor's Polanyi Center in Turmoil
Baylor University's Michael Polanyi Center has been stripped of its name and subjected to intensive reorganization, after a lengthy debate over the existence of the "intelligent design" think tank on the Baptist school's campus.
The controversy began during the spring of 2000 when faculty members expressed their displeasure at the establishment of the Michael Polanyi Center (MPC) without faculty input (see RNCSE 20 [1-2]: 15-16). Particularly displeased were members of the science faculty, who considered the "intelligent design" (ID) focus of the center to be a thinly-veiled form of creation science. Because of faculty criticism, Baylor's President Robert B Sloan Jr agreed to appoint an outside investigating committee.
Committee members visited the campus and interviewed representatives of all sides on September 9 and 10, 2000, and the chair of the committee issued a report on October 17. Written in conciliatory language, the report nonetheless was decidedly lukewarm about the MPC. Although ID claims scientific standing, the committee's report placed the MPC's appropriate mission squarely within the realm of the philosophy of science, as considering "the relationship between the sciences and religion". The committee clearly stated that the Baylor Institute for Faith and Learning (IFL), the institute in which the MPC was housed, should take the university's lead when it came to science and religion issues, and encouraged a broader range of scholarship in this area beyond just ID.
The committee recommended that an advisory committee of Baylor faculty be formed "to assist in planning and reviewing the science and religion component of the Institute". It also called for dropping the name "Michael Polanyi", as the center named for him did not reflect the fact that Polanyi rejected the idea of an agent as creator.
So the Michael Polanyi Center was stripped of its name, placed squarely under the jurisdiction of a philosophy and religion administrative unit, subjected to a faculty advisory committee, and not very subtly put on notice that ID lacked status as a scholarly enterprise.
Nonetheless, on October 17, Director Dembski issued a stirring press release declaring victory for ID and the MPC. Although the Center was placed firmly under the aegis of the IFL, and it was the IFL that was encouraged to go beyond ID in its consideration of science and religion issues, Dembski's press release announced that the MPC had been given a broader mission. The stripping of the name "Polanyi" from the Center was spun as "the Center will therefore receive a new name to reflect this expanded vision". The admonition of the Center to conduct ID research only "when carried out professionally" juxtaposed with the citation of an article harshly critical of Dembski was transformed into "the triumph of intelligent design as a legitimate form of academic inquiry" and an "unqualified affirmation of my own work on intelligent design."
Although many reading the committee's report and Dembski's press release might question whether Dembski "got it", apparently another sentence in the press release got him in trouble. Baylor critics of the MPC would have preferred a more strongly-worded committee report, but in general were satisfied with the results as a compromise between sides with strong disagreements. It appeared that perhaps peace could be restored after the committee's report had been issued. But in his press release, Dembski thumbed his nose at critics, shattering any possibility of effective interaction with a large percentage of the faculty. He gloated, "Dogmatic opponents of design who demanded the Center be shut down have met their Waterloo."
Through newspaper accounts and personal communications, NCSE learned that members of the science faculty and the Baylor Faculty Senate expressed outrage to President Sloan over Dembski's uncollegial behavior, and on October 19, the Director of the Institute for Faith and Learning, Michael Beaty, announced that "Dembski's actions after the release of the report compromised his ability to serve as director" and relieved him of his position. Dembski's associate, Bruce Gordon, described as holding "a PhD in the history and philosophy of physics from Northwestern University, as well as degrees in mathematics, philosophy, theology and piano performance", was appointed as interim director, although he has stated that he does not wish to be the permanent director.
On the same day, Dembski followed up with another press release responding to his dismissal. He claimed that the administration had called him on the carpet, asking that he withdraw his inflammatory press release. Dembski refused on the grounds that he meant what he had said "and that for me to retract it would be tantamount to giving in to the censorship and vilification against me that had been a constant feature since I arrived on campus. I could not and would not betray all that I have worked for in my professional career."
The inflammatory press release became for Dembski a matter of principle, and he accused the administration of "intellectual McCarthyism," a statement that is not likely to mend fences. Ironically, it was President Sloan who had established the MPC, defended it against a faculty outraged at the cavalier way in which it had been established, and supported Dembski all along. Now Dembski was accusing Sloan of "the utmost of bad faith", as if Sloan intended from the beginning to sack him: Dembski claimed that his refusal to withdraw an inflammatory press release "provided the fig leaf of justification for my removal". At the time of this writing, there was no reply from Sloan.
Dembski will continue at the rank at which he was hired, as an untenured "Associate Research Professor" in the Institute for Faith and Learning. The establishment of the MPC was seen as a major step toward achieving the 5-year objectives of the "Wedge" strategy outlined by the Discovery Institute and ID leader Phillip Johnson. This is a long-range plan to establish ID as both a scholarly and a public enterprise, including a hoped-for establishment of an ID institute on a university campus. Baylor's placement of the members of the former Michael Polanyi Center in a relative academic backwater as a subsidiary of a faith and learning institute, and its barely civil recognition of ID as an area that has not achieved much scholarly support, hardly provides the academic credibility for ID sought by Wedge strategists.
As this issue of RNCSE went to press, an article entitled "Intelligent Design Movement Struggles with Identity Crisis" by Bruce Gordon, the interim director of what is now called The Baylor Science and Religion Project, appeared in Research News & Opportunities in Science and Theology (2001 January; 2 [1]: 9). Gordon writes:
The Michael Polanyi Center Peer Review Committee report is available on line at http://pr.baylor.edu/pdf/001017polanyi.pdf. The Baylor administration responds at http://pr.baylor.edu/feat.fcgi?2000.10.17.polanyi.
The controversy began during the spring of 2000 when faculty members expressed their displeasure at the establishment of the Michael Polanyi Center (MPC) without faculty input (see RNCSE 20 [1-2]: 15-16). Particularly displeased were members of the science faculty, who considered the "intelligent design" (ID) focus of the center to be a thinly-veiled form of creation science. Because of faculty criticism, Baylor's President Robert B Sloan Jr agreed to appoint an outside investigating committee.
Committee members visited the campus and interviewed representatives of all sides on September 9 and 10, 2000, and the chair of the committee issued a report on October 17. Written in conciliatory language, the report nonetheless was decidedly lukewarm about the MPC. Although ID claims scientific standing, the committee's report placed the MPC's appropriate mission squarely within the realm of the philosophy of science, as considering "the relationship between the sciences and religion". The committee clearly stated that the Baylor Institute for Faith and Learning (IFL), the institute in which the MPC was housed, should take the university's lead when it came to science and religion issues, and encouraged a broader range of scholarship in this area beyond just ID.
[Science and religion scholarship] ... can best be fostered by the University's Institute for Faith and Learning where it seems to be naturally at home. In pursuing this mission, room should be made for a variety of approaches and topics. It would clearly be too restrictive on the part of the Institute to focus attention in this area on a single theme only, such as the design inference.In its recommendations, the committee continued its lukewarm assessment of the MPC and ID theory. It recognized
... research on the logical structure of mathematical arguments for intelligent design to have a legitimate claim to a place in current discussions of the relations of religion and the sciences. Although this work, involving as it does technical issues in the theory of probability, is relatively recent in origin and has thus only just begun to receive response in professional journals (see, for example, the essay by Elliot Sober in Philosophy of Science 1999; 66: 472-88), the Institute should be free, if it chooses, to include in its coverage this line of work, when carried out professionally.Because the cited article by Sober (and coauthors) is strongly critical of ID, and because the IFL (rather than the MPC) is called upon to include, "if it chooses", only ID research that is carried out professionally, the implication is clear that the committee did not have much confidence in the current scholarly status of ID theory.
The committee recommended that an advisory committee of Baylor faculty be formed "to assist in planning and reviewing the science and religion component of the Institute". It also called for dropping the name "Michael Polanyi", as the center named for him did not reflect the fact that Polanyi rejected the idea of an agent as creator.
So the Michael Polanyi Center was stripped of its name, placed squarely under the jurisdiction of a philosophy and religion administrative unit, subjected to a faculty advisory committee, and not very subtly put on notice that ID lacked status as a scholarly enterprise.
Nonetheless, on October 17, Director Dembski issued a stirring press release declaring victory for ID and the MPC. Although the Center was placed firmly under the aegis of the IFL, and it was the IFL that was encouraged to go beyond ID in its consideration of science and religion issues, Dembski's press release announced that the MPC had been given a broader mission. The stripping of the name "Polanyi" from the Center was spun as "the Center will therefore receive a new name to reflect this expanded vision". The admonition of the Center to conduct ID research only "when carried out professionally" juxtaposed with the citation of an article harshly critical of Dembski was transformed into "the triumph of intelligent design as a legitimate form of academic inquiry" and an "unqualified affirmation of my own work on intelligent design."
Although many reading the committee's report and Dembski's press release might question whether Dembski "got it", apparently another sentence in the press release got him in trouble. Baylor critics of the MPC would have preferred a more strongly-worded committee report, but in general were satisfied with the results as a compromise between sides with strong disagreements. It appeared that perhaps peace could be restored after the committee's report had been issued. But in his press release, Dembski thumbed his nose at critics, shattering any possibility of effective interaction with a large percentage of the faculty. He gloated, "Dogmatic opponents of design who demanded the Center be shut down have met their Waterloo."
Through newspaper accounts and personal communications, NCSE learned that members of the science faculty and the Baylor Faculty Senate expressed outrage to President Sloan over Dembski's uncollegial behavior, and on October 19, the Director of the Institute for Faith and Learning, Michael Beaty, announced that "Dembski's actions after the release of the report compromised his ability to serve as director" and relieved him of his position. Dembski's associate, Bruce Gordon, described as holding "a PhD in the history and philosophy of physics from Northwestern University, as well as degrees in mathematics, philosophy, theology and piano performance", was appointed as interim director, although he has stated that he does not wish to be the permanent director.
On the same day, Dembski followed up with another press release responding to his dismissal. He claimed that the administration had called him on the carpet, asking that he withdraw his inflammatory press release. Dembski refused on the grounds that he meant what he had said "and that for me to retract it would be tantamount to giving in to the censorship and vilification against me that had been a constant feature since I arrived on campus. I could not and would not betray all that I have worked for in my professional career."
The inflammatory press release became for Dembski a matter of principle, and he accused the administration of "intellectual McCarthyism," a statement that is not likely to mend fences. Ironically, it was President Sloan who had established the MPC, defended it against a faculty outraged at the cavalier way in which it had been established, and supported Dembski all along. Now Dembski was accusing Sloan of "the utmost of bad faith", as if Sloan intended from the beginning to sack him: Dembski claimed that his refusal to withdraw an inflammatory press release "provided the fig leaf of justification for my removal". At the time of this writing, there was no reply from Sloan.
Dembski will continue at the rank at which he was hired, as an untenured "Associate Research Professor" in the Institute for Faith and Learning. The establishment of the MPC was seen as a major step toward achieving the 5-year objectives of the "Wedge" strategy outlined by the Discovery Institute and ID leader Phillip Johnson. This is a long-range plan to establish ID as both a scholarly and a public enterprise, including a hoped-for establishment of an ID institute on a university campus. Baylor's placement of the members of the former Michael Polanyi Center in a relative academic backwater as a subsidiary of a faith and learning institute, and its barely civil recognition of ID as an area that has not achieved much scholarly support, hardly provides the academic credibility for ID sought by Wedge strategists.
As this issue of RNCSE went to press, an article entitled "Intelligent Design Movement Struggles with Identity Crisis" by Bruce Gordon, the interim director of what is now called The Baylor Science and Religion Project, appeared in Research News & Opportunities in Science and Theology (2001 January; 2 [1]: 9). Gordon writes:
Design theory has had considerable difficulty gaining a hearing in academic contexts, as evidenced most recently by the whole Polanyi Center affair at Baylor University. One of the principal reasons for this resistance and controversy is not far to seek: design-theoretic research has been hijacked as part of a larger cultural and political movement. In particular, the theory has been prematurely drawn into discussions of public science education, where it has no business making an appearance without broad recognition from the scientific community that it is making a worthwhile contribution to our understanding of the natural world.Later, in what is perhaps a swipe at Dembski's affiliation with the Discovery Institute's Center for the Renewal of Science and Culture, Gordon comments, "If design theory is to make a contribution in science, it must be worth pursuing on the basis of its own merits, not as an exercise in Christian 'cultural renewal,' the weight of which it cannot bear." In his final paragraph, he carefully delineates the nature of design theory's possible contribution to science: "[I]t is crucial to note that design theory is at best a supplementary consideration introduced alongside (or perhaps into, by way of modification) neo-Darwinian biology and self-organizational complexity theory. It does not mandate the replacement of these highly fruitful research paradigms, and to suggest that it does is just so much overblown, unwarranted, and ideologically driven rhetoric." Should Gordon's cautious attitude become more widely adopted by ID proponents, it might alleviate much of the controversy about the status of intelligent design.
The Michael Polanyi Center Peer Review Committee report is available on line at http://pr.baylor.edu/pdf/001017polanyi.pdf. The Baylor administration responds at http://pr.baylor.edu/feat.fcgi?2000.10.17.polanyi.
NCSE Begins Clergy Program
A vital aspect of NCSE's work is cooperation with organizations sharing common concerns. The number and diversity of groups supporting evolution education is reflected by the nearly 100 position statements NCSE collected in Voices for Evolution - a number that has grown since the second edition was published in 1995 (see [centerfold page on which Voices will be offered for sale]).
NCSE has built close working relationships with a number of these organizations, which frequently rely on our expertise in evolution/creation issues, tell individuals needing help to call NCSE, and in turn provide us with needed assistance. However, while our ties with scientific, educational, and civil-liberties organizations are well-developed, our formal ties with religious organizations are less extensive. We also need to develop resources that will be useful to clergy, religious educators, and other people of faith who wish to be voices for evolution both publicly and within their faiths.
Our first steps in this direction have been significant. NCSE contributed to the development of evolution resources on the web site of the Dialogue for Science, Ethics, and Religion (DoSER) of the American Association for the Advancement of Science. Since then, NCSE's Executive Director Eugenie C Scott has joined the DoSER Advisory Committee and participated in a panel discussion of "The Creation/Evolution Controversy: A Philosophical Examination" at a Science and Religion Workshop held by the Center for Theology and the Natural Sciences in June 2000.
Now we are taking further steps to build a grassroots network of religious leaders. NCSE will develop and distribute materials that congregational leaders and religious educators can use to inform themselves and their communities about evolution/creation issues. We will also inform interested individuals of opportunities to speak out for evolution education, since NCSE's experience has been that religious individuals speaking from their faith's perspective are most effective in pointing out that evolution is not inherently anti-religious.
In order to identify people who want to be involved and find out what they need, NCSE has sent a questionnaire to a pilot group of clergy in Kansas asking about conditions in their communities and their willingness to work on this issue. We received a very good response and are now working with other organizations to reach more interested individuals. We are also working with an increasing number of interfaith groups and social action agencies of some denominations.
Now you can help. Tell NCSE whether you or someone you know is interested in learning more about our clergy network - or in telling someone else about it; write to Molleen Matsumura at interfaith@ncseweb.org, or at NCSE, PO Box 9477, Berkeley, CA 94709-0477.
NCSE wishes to thank Caroline McKnight and the Rev. Bob Meneilly of the Kansas MAINstream Coalition for their assistance.
NCSE has built close working relationships with a number of these organizations, which frequently rely on our expertise in evolution/creation issues, tell individuals needing help to call NCSE, and in turn provide us with needed assistance. However, while our ties with scientific, educational, and civil-liberties organizations are well-developed, our formal ties with religious organizations are less extensive. We also need to develop resources that will be useful to clergy, religious educators, and other people of faith who wish to be voices for evolution both publicly and within their faiths.
Our first steps in this direction have been significant. NCSE contributed to the development of evolution resources on the web site of the Dialogue for Science, Ethics, and Religion (DoSER) of the American Association for the Advancement of Science. Since then, NCSE's Executive Director Eugenie C Scott has joined the DoSER Advisory Committee and participated in a panel discussion of "The Creation/Evolution Controversy: A Philosophical Examination" at a Science and Religion Workshop held by the Center for Theology and the Natural Sciences in June 2000.
Now we are taking further steps to build a grassroots network of religious leaders. NCSE will develop and distribute materials that congregational leaders and religious educators can use to inform themselves and their communities about evolution/creation issues. We will also inform interested individuals of opportunities to speak out for evolution education, since NCSE's experience has been that religious individuals speaking from their faith's perspective are most effective in pointing out that evolution is not inherently anti-religious.
In order to identify people who want to be involved and find out what they need, NCSE has sent a questionnaire to a pilot group of clergy in Kansas asking about conditions in their communities and their willingness to work on this issue. We received a very good response and are now working with other organizations to reach more interested individuals. We are also working with an increasing number of interfaith groups and social action agencies of some denominations.
Now you can help. Tell NCSE whether you or someone you know is interested in learning more about our clergy network - or in telling someone else about it; write to Molleen Matsumura at interfaith@ncseweb.org, or at NCSE, PO Box 9477, Berkeley, CA 94709-0477.
NCSE wishes to thank Caroline McKnight and the Rev. Bob Meneilly of the Kansas MAINstream Coalition for their assistance.
Creationism and Pseudomathematics
We are well aware of anti-evolutionists' fondness for presenting their audiences with numbers of dizzying magnitude that they use to represent incredibly low probabilities for such events as the chance formation of a protein molecule, the origin of life, and the like. Thus they argue that it is irrational to believe that the event in question could have happened naturally (they mean "by chance") without the aid of intelligent design. In some cases, such as the chance formation of habitable planets, one may avoid a technical discussion of the physical processes involved and respond simply by pointing out that the universe is a very big place, containing countless galaxies, stars, and planetary systems, thus providing so much opportunity for the natural occurrence of the event in question that the probability may be quite high that such an event would occur somewhere. Furthermore, if the universe is infinite, providing the event with infinitely many chances to occur, then the occurrence of the event is a virtual certainty. Thus creationist probability arguments can often be undermined by pointing out that any event with a probability greater than 0, no matter how low, will be likely to happen if given enough opportunity, and sure to happen if opportunity is unlimited.
This principle is sometimes illustrated with the following thought experiment (of which the reader has probably heard one version or another): Suppose that a monkey, trained to hit the keys of a typewriter one by one in a truly random fashion, types forever, producing infinitely many pages of text. No one doubts that the monkey would type page after page of gibberish, but it follows from the above principle that sooner or later the monkey would type all of the works of Shakespeare from beginning to end, without error, solely by accident.
Unfortunately, this result of the thought experiment, and thus the principle itself, is sometimes explicitly rejected by creationists. One way of trying to justify their denial of this principle is by an appeal to what creationists refer to as Borel's single law of chance - a claim made by the French probability theorist Emile Borel. According to creationists, Borel's single law of chance says that any event with a probability lower than 1 in 1050 is so improbable as to be impossible (Kennedy 1980: 57; Ankerberg and Weldon 1998: 183; Harber 1998: 33; Mastropaolo 1999: iii). The implication is that, since the origin of life, the evolution of humans, and many other events may have a probability below this limit, they could not possibly have happened by chance no matter how much opportunity there may have been for them to occur.
Thus creationists attempt to protect their probability arguments from our sufficient opportunity principle by invoking this single beloved mathematical law. Borel did in fact propose such a law. However, just as creationists have misrepresented the second law of thermodynamics, so have they misrepresented Borel's law of chance. So what did Borel really mean? Here is an illustration.
On the other hand, we can imagine other events (such as a monkey's accidentally typing Shakespeare) that are so improbable that the entire observable universe cannot provide enough opportunity for us rationally to expect the event in question to occur. Any event of this sort that has any probability at all is still possible - it is just that it would be foolish to bet on its occurrence, not only at a particular place or time, but anywhere ever (within the spatial and temporal confines of the observable universe). Borel said that such events, having a probability of no more than roughly 1 in 1050, never occur (Borel 1965: 57). But this law of chance is not literally true, for, as we shall see, such events can and do happen. I think that a more accurate way to say what Borel had in mind is that in reality, no such event can be rationally predicted ever to occur.
Unfortunately, because, I suspect, of the carelessness of creationists' research, they have failed to grasp Borel's law and instead have taken his claim at face value - as saying literally that events of such low probabilities cannot possibly occur! For example, according to Scott Huse, "[M]athematicians generally consider any event with a probability of less than 1 chance in 1050 as having a zero probability ([that is] it is impossible)" (Huse 1997: 123). So in effect we are told that according to Borel's single law of chance, even if the observable universe did provide unlimited opportunity for their occurrence, such events are just too improbable ever to occur (Ankerberg and Weldon 1998: 329-30). It is this claim with which I take issue (as would Borel), for though one need not be learned in mathematics to find the claim questionable, many laypeople, I fear, may find it all too easy to believe.
By way of example, suppose that one were to program a computer to generate 100 random digits. There would be 10100 equally likely possible outcomes. The probability of any given outcome would thus be 10-100. Applying the creationist "law of chance", we would have to conclude that any conceivable outcome, because it has a probability less than 1 in 1050, is literally impossible, having no chance of occurring and thus having a probability of 0 (see the Huse quote above). But clearly no event can have a probability of 1 in 10100and a probability of 0 (unless we think that 1/10100 = 0, which is as false as the claim that 2 + 2 = 5). Moreover, since the conceivable outcomes are what mathematicians call mutually exclusive and jointly exhaustive, the sum of all their individual probabilities must equal 1, which they cannot do if they are all 0.
Fortunately, one need only carry out this experiment to see the anti-evolutionists' version of this "law of chance" falsified. For surely some outcome must be realized when we instruct the computer to select 100 random digits, despite the fact that the calculated probability of each outcome that the computer could produce falls far below the supposed threshold of possibility. (Borel, on the other hand, would say that no preconceived outcome could be rationally expected to occur, because the probability of successfully guessing the outcome in advance is too low for it to be expected to happen in the real world.) Thus we see that the anti-evolutionist appeal to Borel's law of chance fails to refute the principle that any event with a positive probability, no matter how small, is bound to happen somewhere sometime if given infinitely many chances.
For example, Patrick Glynn, in God: The Evidence, criticizes our thought experiment about the endlessly typing monkey in this way:
Let us say that Shakespeare's Hamlet is x typed pages long, y is the number of characters that can fit on a page, and z is the number of characters on a typewriter. Thus a text x pages long contains xy characters, each of which could be any one of z possibilities. There are then zxy possible ways of randomly typing x pages of text, all of which are equally likely and exactly one of which is Hamlet. Now suppose that we divide the monkey's work into trials, the first trial consisting of the first x pages typed, the second trial consisting of the second x pages, and so on. Since the monkey will ultimately type infinitely many pages, he will ultimately type infinitely many trials. Each trial is an opportunity for the monkey to type Hamlet. (I am, of course, ignoring the possibility that the monkey might begin typing Hamlet midway through one trial and finish it midway through the next.)
On any given trial, the probability that the monkey will type Hamlet is 1/zxy, which we shall call p. And on any given trial, the probability that the monkey will fail to type Hamlet is 1-p, which we shall call q. Thus the probability of failure is q for the first trial, q for the second trial, q for the third trial, and so on. Consider now the probability of failure on the first 2 trials, which is q2, and the probability of failure on the first 3 trials, which is q3, and so on. We thus see that the probability of failure on all of the first n trials is qn. What then is the probability that the monkey will fail on all the trials, that he will never type Hamlet? Since there are infinitely many trials, the probability could be expressed as q raised to the power of infinity.
But what are we to make of this? Since zxy is a finite positive number, 1/zxy (the probability on any trial that the monkey will type Hamlet) must be greater than 0. And p = 1/zxy, so p > 0. Since p > 0, we know that 1-p is smaller than 1. And since 1-p = q, it follows that q must be smaller than 1. Thus we see that q, the probability on any given trial that the monkey will fail to type Hamlet, must be a real number greater than 0 and less than 1. Now if we pick any number on the number line greater than 0 and less than 1 (q is such a number) and multiply it by itself many times, thus raising it to higher and higher powers, the product will approach 0; the higher the power, the closer to 0 the product will be. If the power is infinite, the ultimate result, in the end, is 0. Therefore, q to the power of infinity is 0.
Now recall that q to the power of infinity is the probability that the monkey would never type Hamlet. And we have just seen that this probability is 0. This means that there is a probability of 1, or 100%, that the monkey will type Hamlet at least once over the course of eternity. It would be a miracle if he did not! The same goes for every other work of Shakespeare, as well as the Bible, War and Peace, this article, your personal diary, anything imaginable (of finite length) - you name it, the monkey will eventually type it.
In fact, this principle is not limited to this thought experiment about the monkey typing, but is applicable to any improbable event whatsoever. Provided it has a constant positive probability (to be represented by p), the event in question is certain to happen if given unlimited opportunity. Any attempt to deny this, whether based on Borel's law of chance, common horse sense, or anything else, is misguided.
Second, and more importantly, even if all the scientific matters had been discussed, it would make no difference. The opponents of evolution are not interested in good science, and as I have attempted to show in this article, neither are they interested in good mathematics. Hence their arguments are not based on a complete and contemporary understanding of the scientific and mathematical principles that are relevant to the issue. This is yet another reason why creationist material has no business being taught in science classes - it threatens our students' education not only with bad science, but also bad mathematics.
This principle is sometimes illustrated with the following thought experiment (of which the reader has probably heard one version or another): Suppose that a monkey, trained to hit the keys of a typewriter one by one in a truly random fashion, types forever, producing infinitely many pages of text. No one doubts that the monkey would type page after page of gibberish, but it follows from the above principle that sooner or later the monkey would type all of the works of Shakespeare from beginning to end, without error, solely by accident.
Unfortunately, this result of the thought experiment, and thus the principle itself, is sometimes explicitly rejected by creationists. One way of trying to justify their denial of this principle is by an appeal to what creationists refer to as Borel's single law of chance - a claim made by the French probability theorist Emile Borel. According to creationists, Borel's single law of chance says that any event with a probability lower than 1 in 1050 is so improbable as to be impossible (Kennedy 1980: 57; Ankerberg and Weldon 1998: 183; Harber 1998: 33; Mastropaolo 1999: iii). The implication is that, since the origin of life, the evolution of humans, and many other events may have a probability below this limit, they could not possibly have happened by chance no matter how much opportunity there may have been for them to occur.
Thus creationists attempt to protect their probability arguments from our sufficient opportunity principle by invoking this single beloved mathematical law. Borel did in fact propose such a law. However, just as creationists have misrepresented the second law of thermodynamics, so have they misrepresented Borel's law of chance. So what did Borel really mean? Here is an illustration.
Lightning Strikes - Often!
Hardly any of us really worries about getting struck by lightning. The probability that any individual will ever be struck by lightning is extremely low. But with so many people in the world, there is ample opportunity for this rare event to happen from time to time. It would be amazing if it never happened; and indeed many of us do know of such an event. Thus there are some highly improbable events that may be rationally expected to happen occasionally.On the other hand, we can imagine other events (such as a monkey's accidentally typing Shakespeare) that are so improbable that the entire observable universe cannot provide enough opportunity for us rationally to expect the event in question to occur. Any event of this sort that has any probability at all is still possible - it is just that it would be foolish to bet on its occurrence, not only at a particular place or time, but anywhere ever (within the spatial and temporal confines of the observable universe). Borel said that such events, having a probability of no more than roughly 1 in 1050, never occur (Borel 1965: 57). But this law of chance is not literally true, for, as we shall see, such events can and do happen. I think that a more accurate way to say what Borel had in mind is that in reality, no such event can be rationally predicted ever to occur.
Unfortunately, because, I suspect, of the carelessness of creationists' research, they have failed to grasp Borel's law and instead have taken his claim at face value - as saying literally that events of such low probabilities cannot possibly occur! For example, according to Scott Huse, "[M]athematicians generally consider any event with a probability of less than 1 chance in 1050 as having a zero probability ([that is] it is impossible)" (Huse 1997: 123). So in effect we are told that according to Borel's single law of chance, even if the observable universe did provide unlimited opportunity for their occurrence, such events are just too improbable ever to occur (Ankerberg and Weldon 1998: 329-30). It is this claim with which I take issue (as would Borel), for though one need not be learned in mathematics to find the claim questionable, many laypeople, I fear, may find it all too easy to believe.
All Nonzero Probabilities Are Possible
The probability of an event is expressed as a real number from 0 to 1; the more probable the event, the higher the number. An event can have only one probability at any time, just as a person at any given time can have only one age. However, anti-evolutionists misconstrue Borel's law of chance to imply the absurdity that low-probability events are assigned 2 different probabilities - their true probability and a probability of 0.By way of example, suppose that one were to program a computer to generate 100 random digits. There would be 10100 equally likely possible outcomes. The probability of any given outcome would thus be 10-100. Applying the creationist "law of chance", we would have to conclude that any conceivable outcome, because it has a probability less than 1 in 1050, is literally impossible, having no chance of occurring and thus having a probability of 0 (see the Huse quote above). But clearly no event can have a probability of 1 in 10100and a probability of 0 (unless we think that 1/10100 = 0, which is as false as the claim that 2 + 2 = 5). Moreover, since the conceivable outcomes are what mathematicians call mutually exclusive and jointly exhaustive, the sum of all their individual probabilities must equal 1, which they cannot do if they are all 0.
Fortunately, one need only carry out this experiment to see the anti-evolutionists' version of this "law of chance" falsified. For surely some outcome must be realized when we instruct the computer to select 100 random digits, despite the fact that the calculated probability of each outcome that the computer could produce falls far below the supposed threshold of possibility. (Borel, on the other hand, would say that no preconceived outcome could be rationally expected to occur, because the probability of successfully guessing the outcome in advance is too low for it to be expected to happen in the real world.) Thus we see that the anti-evolutionist appeal to Borel's law of chance fails to refute the principle that any event with a positive probability, no matter how small, is bound to happen somewhere sometime if given infinitely many chances.
Typing Monkeys and the Classics
Another way that anti-evolutionists try to get around this principle is simply by a dubious appeal to common sense. As one apologist argues, "It does not matter how much time we give nature; the large numerical odds simply are irrelevant: we must simply admit that no matter how much time and how much luck, evolution could not have happened" (Lutzer 1998: 159). Unfortunately, common sense is not always, and certainly not in this case, a reliable guide to mathematical truth.For example, Patrick Glynn, in God: The Evidence, criticizes our thought experiment about the endlessly typing monkey in this way:
[I]t does not matter if there is an infinity of days. ... It is a gross fallacy to suppose that the quantity of days or time available changes anything. (To put the proposition mathematically, the probability on any given day that the monkey will type the works of Shakespeare . . . is not one in some very, very large number; it is zero.) Randomness does not engender order on any appreciable scale, no matter how many billions of years or opportunities you give it (Glynn 1997: 46).But instead of relying on gut instinct, let us see if a far more reliable appeal to probability theory cannot shed some light on the subject. (Borel's law of chance is of no use to us here, for it is applicable only to real world cases, not hypothetical cases like this where we have eternity at our disposal.)
Let us say that Shakespeare's Hamlet is x typed pages long, y is the number of characters that can fit on a page, and z is the number of characters on a typewriter. Thus a text x pages long contains xy characters, each of which could be any one of z possibilities. There are then zxy possible ways of randomly typing x pages of text, all of which are equally likely and exactly one of which is Hamlet. Now suppose that we divide the monkey's work into trials, the first trial consisting of the first x pages typed, the second trial consisting of the second x pages, and so on. Since the monkey will ultimately type infinitely many pages, he will ultimately type infinitely many trials. Each trial is an opportunity for the monkey to type Hamlet. (I am, of course, ignoring the possibility that the monkey might begin typing Hamlet midway through one trial and finish it midway through the next.)
On any given trial, the probability that the monkey will type Hamlet is 1/zxy, which we shall call p. And on any given trial, the probability that the monkey will fail to type Hamlet is 1-p, which we shall call q. Thus the probability of failure is q for the first trial, q for the second trial, q for the third trial, and so on. Consider now the probability of failure on the first 2 trials, which is q2, and the probability of failure on the first 3 trials, which is q3, and so on. We thus see that the probability of failure on all of the first n trials is qn. What then is the probability that the monkey will fail on all the trials, that he will never type Hamlet? Since there are infinitely many trials, the probability could be expressed as q raised to the power of infinity.
But what are we to make of this? Since zxy is a finite positive number, 1/zxy (the probability on any trial that the monkey will type Hamlet) must be greater than 0. And p = 1/zxy, so p > 0. Since p > 0, we know that 1-p is smaller than 1. And since 1-p = q, it follows that q must be smaller than 1. Thus we see that q, the probability on any given trial that the monkey will fail to type Hamlet, must be a real number greater than 0 and less than 1. Now if we pick any number on the number line greater than 0 and less than 1 (q is such a number) and multiply it by itself many times, thus raising it to higher and higher powers, the product will approach 0; the higher the power, the closer to 0 the product will be. If the power is infinite, the ultimate result, in the end, is 0. Therefore, q to the power of infinity is 0.
Now recall that q to the power of infinity is the probability that the monkey would never type Hamlet. And we have just seen that this probability is 0. This means that there is a probability of 1, or 100%, that the monkey will type Hamlet at least once over the course of eternity. It would be a miracle if he did not! The same goes for every other work of Shakespeare, as well as the Bible, War and Peace, this article, your personal diary, anything imaginable (of finite length) - you name it, the monkey will eventually type it.
In fact, this principle is not limited to this thought experiment about the monkey typing, but is applicable to any improbable event whatsoever. Provided it has a constant positive probability (to be represented by p), the event in question is certain to happen if given unlimited opportunity. Any attempt to deny this, whether based on Borel's law of chance, common horse sense, or anything else, is misguided.
The Heart of the Matter
Anti-evolutionists, of course, will continue to employ their probability arguments against the natural formation of proteins, cells, and the like, despite everything said in this article. There are two reasons for this. First, in all fairness, their probability arguments often cannot be adequately refuted without a highly technical scientific explanation of the physical processes involved in the "improbable" event in question, and no such discussion was attempted here for the same reason that none is often attempted in public discussions of the issues.Second, and more importantly, even if all the scientific matters had been discussed, it would make no difference. The opponents of evolution are not interested in good science, and as I have attempted to show in this article, neither are they interested in good mathematics. Hence their arguments are not based on a complete and contemporary understanding of the scientific and mathematical principles that are relevant to the issue. This is yet another reason why creationist material has no business being taught in science classes - it threatens our students' education not only with bad science, but also bad mathematics.
References
Ankerberg J, Weldon J. Darwin's Leap of Faith. Eugene (OR): Harvest House Publishers, 1998.Borel E. Elements of the Theory of Probability. Englewood Cliffs (NJ): Prentice-Hall, Inc., 1965.
Glynn P. God: The Evidence: The Reconciliation of Faith and Reason in a Postsecular World. Rocklin (CA): Prima Publishing, 1997.
Harber F. Reasons for Believing: A Seeker's Guide to Christianity. Green Forest (AR): New Leaf Press, 1998.
Huse SM. The Collapse of Evolution. 3rd ed. Grand Rapids (MI): Baker Books, 1997.
Kennedy DJ. Why I Believe. Dallas (TX): Word Publishing, 1980.
Lutzer EW. Seven Reasons Why You Can Trust the Bible. Chicago: Moody Press, 1998.
Mastropaolo J. Evolution is biologically impossible. Impact 1999 Nov; 317.
Design and its Critics: Yet Another ID Conference
Concordia University in Mequon, Wisconsin, was the site of another "Intelligent Design" conference held on June 22-24, 2000. Under the rubric "Design and Its Critics" (DAIC), the conference brought together the leading lights of the "Intelligent Design" (ID) movement with several critics from a variety of disciplines in the natural sciences, social sciences, and humanities. There was a variety of plenary and concurrent sessions throughout the weekend, so we are able to present only the highlights of the conference.
Meyer went on to claim that ID provides a better explanation than evolutionary theory in several instances. First, Meyer argued that ID provides a better explanation of the origin of "information", in particular the origin of DNA, than does evolution. Next he claimed that ID provides a better explanation of the Cambrian Explosion — the sudden appearance of new phyla in the fossil record 570 million years ago — because new organisms require a new information code. According to Meyer, this situation does not fit a "Darwinian" model, because the mere shuffling of genes is not sufficient to produce this variety (though he provided no support for this assertion). In Meyer's view, the shortcomings of evolutionary models confirm ID by default.
Meyer rehearsed the standard mistaken creationist critiques based on biochemical complexities and specificities of modern organisms, but added an interesting — if misconstrued — discussion of the origin of DNA. Since DNA provides the instruction set for proteins, Meyer asked, what is the causal explanation of the DNA code? Citing Stanley Miller's experiments as proof that the prebiotic atmosphere was unsuitable for sustaining life, Meyer concluded that there was no natural prebiotic source of the information encoded in DNA. Any precursor molecules would be subject to interfering cross-reactions, and the limited time and resources combined with the required sequence specificity (for a fully functioning 100-amino-acid protein) would have precluded de novo synthesis. Meyer tried to apply a version of Dembski's "explanatory filter", arguing that the low probability and the complex specification of the DNA molecule require us to conclude that it had been designed.
The main focus of the rest of Meyer's presentation was the supposed evidence for the design of DNA -- the information content of living things. Meyer argued that natural selection cannot explain the origin of information, because it presupposes a freely replicating system — one that operates on DNA and protein (of course, natural selection is not concerned with, nor does it try to explain, the origin of "information"). Furthermore, Meyer argued that there are no forces in evolutionary theory to explain the sequential order of DNA, apparently because he believes that, according to evolutionary biologists, nucleotide base organization should be random. Of course, in most organisms many repetitive sequences in DNA, noncoding introns ("nonsense" DNA), and "junk" DNA are not constrained by strict sequential relationships. These random elements constitute a very large fraction of the genome.
Meyer constructed a straw man by focusing on DNA and fully functioning proteins. No working evolutionary scientist believes that life originally appeared fully equipped with the present complex DNA and protein repertoire. One leading theory of early life is the RNA world hypothesis, about which, in the question period, Meyer showed that he is absolutely misinformed, falsely claiming that RNA could neither replicate nor make peptide bonds. The question period ended before he could be fully questioned on this topic, but there are several published papers that show that Meyer was attacking strawman arguments about DNA, RNA, and information origin (Zhang and Cech 1997, Wright and Joyce 1997).
Michael Shermer took the stage next. His presentation was more theatrical (complete with a laser pointer that projected the shape of a UFO). He made some very good points, but I do not think that most of the audience was sufficiently engaged by his presentation. Natural selection, Shermer said, preserves gains and eliminates mistakes; "Intelligent Design" assumes that the current function of structures in living things is the same as the original function. He argued that ID is not useful scientifically because it leads to an investigative dead end — the actions of an intelligent designer.
Behe next responded to Ken Miller's Finding Darwin's God. He focused on the lac operon — a genetic sequence in E coli bacteria that regulates the production of 3 enzymes necessary for the digestion of lactose. If any component of this multipart system is eliminated, argued Behe, the system becomes nonfunctional Although Kenneth Miller had cited experiments showing that when the one of the lac operon genes — the (-galactosidase gene — is knocked out, bacteria can re-acquire this function, Behe disputed this conclusion, because, he said, it was necessary to generate an artificial system using "intelligent intervention" that added other components to the system before the function could be restored.
Behe's next example of IC was the blood-clotting cascade. Behe illustrated the complexity of this system and claimed that removal of any of the components is highly deleterious and causes the whole process to collapse. Citing research with transgenic organisms, Behe argued that these systems are irreducibly complex, because they contain many parts that must be well coordinated with one another to function — therefore, they could not have arisen by natural selection working through gradual, Darwinian mechanisms.
Next up was Scott Minnich, whose talk focused on the research on the bacterial flagellum. He gave a very nice, purely scientific talk on research in the field, which did not seem to fit in here because it seemed that a substantial part of his talk contradicted the assertion of irreproducible complexity. For example, he discussed the virulence plasmid found in the bacterium that causes bubonic plague, which, as it turns out, contains several genes that are highly homologous to those that code for flagellar proteins. In the plasmid, these genes code for proteins that make up structures that drill holes into host cells and inject them with poison. Here we have an example where one set of genes codes for flagellar proteins, however a homologous subset of those genes codes for an entirely different structure (hole drilling apparatus). In an IC structure, if a single component is removed, the structure loses its specific function. But complex structures need not lose all physiological function when one component is changed. The exaptation of an existing structure — such as occurs in the protein products of the virulence plasmid — to a structure performing a new function — such as the flagellum — is precisely the sort of change evolution would predict. Minnich's example endangers only the straw man position that these cellular structures must preserve their existing functions as their protein composition or sequence is modified.
Ken Miller spoke next, presenting a step-by-step, systematic critique of Behe's argument. First he pointed out, in contrast to the assumptions of IC, that no scientist proposes that complex macromolecular systems spontaneously arose in their currently functioning state. Instead, individual components of the larger system probably had other functions, and, through gene duplication or other mechanisms, they took on new functions. These processes permitted the acquisition of new functions and opportunities to interact with other molecules to provide intermediaries with novel functions.
Miller spent a great deal of time describing how the flagellum might have evolved, providing numerous examples of organisms that illustrate the mechanisms and processes that he proposed. He also gave examples of flagella that have some components missing but still function. The example that made the best impression on the audience was that of eel sperm. The missing components make the flagellum appear nonfunctional, said Miller, but, he reminded the audience, since these sperm are very good at making baby eels, the flagellum clearly must function — despite its having "missing" parts.
Next Miller discussed the Krebs cycle — a series of chemical reactions common to living things that extracts energy from carbohydrate molecules — showing how a variety of organisms use different parts of the cycle for different functions. All the while Miller reminded the audience that according to IC, the loss or alteration of one component from an IC system makes the system nonfunctional. At the same time, he reminded the audience that complex systems evolve by co-opting pre-existing, functioning components to serve new functions in new ways.
Miller also presented a bibliographic search (on Medline) showing that there have been only 2 articles on IC in the peer-reviewed literature since 1966, neither one of which appeared in a peer-reviewed scientific research journal. Finally, he took on the central "commonsense" analogy of IC — the irreducibly complex mousetrap. He demonstrated fully functional 5-part, 4-part, 3-part, 2-part and even 1-part mousetraps, concluding by pointing out how, as in biology, the mousetrap that serves one function can be adapted for others (He cited the mousetrap key chain and the mousetrap tie-tack).
A question-and-answer period followed the presentations. As might be expected, Behe took exception to many of Miller's criticisms, denying that he had ever said the things for which Miller took him to task. This is a dangerous tactic in the digital age when your opponent is armed with a laptop computer. Miller was able to provide precise quotations and citations from Behe's work to support his claims. Behe was backpedaling throughout the entire session, and not many questions were asked of the speakers.
During this session, I (JO) introduced myself as a population geneticist from Rush Medical Center in Chicago and said that I had 3 related observations that led to a practical question. First, my research focuses on the identification of genes responsible for complex autoimmune diseases. Evolutionary theory provides the basis for the genetic algorithms that I use in my research. Second, 2 weeks earlier I had visited a pharmaceutical company that also uses evolutionary algorithms to aid in the identification of different alleles affecting drug-metabolizing enzymes. Third, I recently met a researcher at Marquette University who uses evolutionary algorithms to aid in identification of amino-acid residues critical for function of a very complex protein. My question — an open question to both of the ID proponents — was: As practical people, looking for the fastest, most efficient method to reach our goals., how would Intelligent Design help us in our endeavors? What would ID predict in these different systems?
Behe answered the question by commenting that ID would tell us where to look, and perhaps which systems would be irreducibly complex. I replied that his answer really did not answer my question. In the real world of scientific research, I reiterated, evolutionary theory provides algorithms that suggest how to go about finding what we are looking for; these algorithms are used successfully in many fields — including by pharmaceutical companies that are primarily interested in making money. How would ID provide a superior model for accomplishing these goals? Behe answered by mumbling something about needing to see what algorithms I am using. Then the session was closed.
My question sparked discussion afterwards, and I had opportunity to talk with quite a few different people. The general consensus of these people (with the exception of one oddball who basically contended that we are all de-evolving into the blackness of Hell) was that my question really went to the crux of the issue of whether ID has anything useful to present to the scientific community. Scientific theories not only explain and make sense of our observations, but also provide questions and predictions that support useful and productive research.
The claim that ID only has power to retrodict is an evasive maneuver that may sound nice in a sound bite. But the fact is that a theory that only retrodicts is a scientifically worthless idea that does not merit the title of theory. ID is based entirely on the assumption that when science reaches a stumbling block, the appropriate response is to throw up one's hands, say "I don't understand how this could be put together naturally" and to claim that it was intelligently designed. In this way ID is actually more scientifically bankrupt than young-earth creationism, which at least makes testable predictions. ID is invoked only when regular science gets stuck (for the moment).
The second major event on Saturday was a panel discussion entitled "Prospects for Design". The participants were Paul Nelson, Edward Davis, Kelly Smith, and Lenny Moss. Nelson told the audience that the real issue is to provide an argument against methodological naturalism (MN), which he called one of the worst philosophies of science. Nelson characterized MN as absolute rubbish and characterized himself as someone interested in getting at the truth about the world. He said that his purpose was to show the limits of MN, not to set out the future direction of ID.
Nelson provided a definition of MN based on the characterization by the National Academy of Sciences (NAS): "The statements of science must invoke only natural things and processes" (NAS 1998: 42). Nelson's question to the audience was, "Should this be so? Should we separate the natural from the supernatural?" Nelson argued that we should discard the supernatural-natural distinction in favor of the intelligent-natural distinction. We should, Nelson said, institute a research program for intelligent causation — but true to his promise, Nelson did not suggest what such a program would entail.
Most of Nelson's presentation was an exploration of how MN supposedly limits our ability to find out what is true. In Nelson's example, a homicide detective faced with a dead body must consider 4 possible explanations in order to determine the real cause of death. Two of these require no intelligent agent — natural causes and accidents — but the other 2 are caused by the actions of just such an agent — suicide and homicide. According to Nelson, MN would limit the homicide detective's investigation to death by natural causes or accident and would leave out suicide and homicide — both actions of an intelligent agent. In the real world, Nelson argued, even if death were never to occur by suicide and homicide, they would remain causal probabilities — that is, they could occur — and, according to Nelson, if we do not consider homicide and suicide to determine that they do not explain the death we are investigating, then we cannot know for sure that our explanations are true. Unless he considers and rules out the possibility of murder and suicide, the detective cannot be justifiably confident that he has solved the case. Likewise, Nelson argued, we should not exclude intelligent design from the scientific "toolkit".
According to MN, Nelson told the audience, the tools in the scientific toolkit are natural laws (Nelson called them "physical" laws) and chance. Nelson argued that a third tool, intelligent design, belongs in the toolkit of science too. Even if we never need to invoke ID, Nelson told the audience, a naturalistic interpretation of evidence can never be completely justified unless ID is considered and ruled out. Even Darwin lived and worked in an environment with all 3 tools, said Nelson, and it did no harm to his science. Likewise, Nelson assured us, it will do no harm for us to consider ID when the evidence warrants it.
In summary, Nelson argued that science cannot discover what it excludes a priori. If science is a truth-seeking endeavor (as he assumes), then MN belongs on the rubbish heap of history because it limits scientists to a flawed investigative process that fails to include all the explanatory possibilities.
Edward Davis spoke next. He said that he accepts that there is purpose in the universe, although he has concerns about how the issues are framed in the current models of ID. He chose to explore how we understand the meaning of apparent design in Nature through recent research that he has been conducting on the works of Robert Boyle — a 17th-century chemist and natural philosopher best known for his laws about the behavior of gases and his use of controlled experiments.
Although Boyle argued for "design" in the natural world, Davis pointed out that this design represented neither ongoing tinkering by an intelligent agent nor what passed for the contemporary version of the anthropic principle -a philosophy of science that assumed that Nature was constructed benevolently to promote human well-being. Instead, although Boyle was convinced that experimental science would demonstrate the existence of God, he felt that the route to this demonstration was through an understanding of the mechanics of the way things really worked in the natural world. In Boyle's view, God works through the "mechanisms" that show His presence and actions. Boyle felt that the scientific process is short-circuited by teleological explanations, even if there is an ultimate purpose to the universe. He thus insisted on naturalistic explanations for natural phenomena first and foremost whenever possible.
Although he told the audience that he agreed that evidence of purpose is found in the natural world, Davis argued that it is neither appropriate nor productive to look for it in the same ways and places that one looks for evidence of natural processes. Davis told the audience that he believes "in a God who is sovereign over the laws of Nature". However, he noted, the world is not full of items stamped "Made by God"; God is more subtle than that. So the evidence for God's purposes may not be the same physical evidence that we find in natural phenomena that scientists study, say, in the behaviors of gases under pressure or mutation rates.
The most serious problem with ID, Davis told the conference, is that it appears to make the existence of God (the unnamed "intelligent designer") an additional hypothesis to be tested scientifically. However, this runs counter to the central understanding of God in Christian and Jewish traditions. Davis told the audience that the central claim of Christianity, for example, is that we have actually seen God directly, and when we did not like what we saw, we killed him — then he surprised us. Davis said that we need to incorporate the interaction between God and the world into our discourse in this way, not as specific scientific hypotheses about individual events and structures.
The next speaker was Kelley Smith. He presented a "blueprint for respectability" — an outline for how ID could earn itself a place at the scientific table. Smith's remarks are included elsewhere in this issue. In summary, he outlined a program that would turn ID from a fringe idea to a respectable theory in the sciences, along with all the benefits that respectability offers — respect, funds, access to classrooms, and a place in mainstream textbooks and journals. This was the route taken by all successful challengers to the scientific status quo. But he doubted that ID proponents would take his advice.
The last speaker in the panel was Lenny Moss, who argued that the key issue under discussion was the nature of Nature. According to Moss, ID assumed a very narrow notion of Nature, defining its position by its opposition to the viewpoints of a few prominent proponents of philosophical naturalism, such as Richard Dawkins and Daniel Dennett. Moss argued that ID, if it is to be successful, needs to define itself in its own terms, not merely in opposition to what are extreme positions even among natural scientists.
Taking Dawkins and Dennett to task is a good tactical approach, Moss told the conference, for it allows the proponents of ID to press the naturalistic explanation and show where it is in trouble — a debunking strategy. However good a tactical approach it may be to oppose what he called the strict neo-Darwinism of Dawkins and Dennett, Moss said, it is nonetheless a bad strategic approach. That is, to accept that naturalism is restricted to the premises of neo-Darwinism "sells Nature down the river" by restricting naturalism to a particular, limited version of naturalism espoused by Dawkins and Dennett. The most fruitful answer to a dogmatic metaphysics (like that of Dawkins or Dennett), said Moss, is not another dogmatism, but a pluralistic approach. Reacting against a strict neo-Darwinism with a dogmatic approach — whether it is ID or some other dogmatism — leads to bad biology. Instead, Moss argued for a broader perspective for both ID and for naturalism.
In considering the future prospects for ID, there is, Moss said, good news and bad news. As for the good news, Moss argued that science is at a historic juncture — at a new "crisis" in the struggle to resolve our "intuition for life". He traced our understanding of Nature from the 17th century, when science changed its understanding of natural events and organisms as ends unto themselves to a view of these phenomena as the outcome of other natural processes and interactions. This change culminated in the 20th century when, Moss argued we now understand natural events and organisms as only the outcome of natural processes and their interactions. One aspect of this important historic juncture is the Human Genome Project.
Moss told the conference that there are promissory notes that need to be called in — things that biology has promised and not yet delivered. It is time to move beyond the 17th-century view of matter and the physical world to a new scientific understanding that can do justice to the agency of life. This "new naturalism" is one that would allow a pluralistic view of agency in the emergence and direction of life, and one that may make substantial contributions to our understanding of Nature. In reviving a sort of preformationist, vitalistic approach, ID may figure into Moss's "new naturalism".
The bad news for ID is that it seems to be mired in its opposition to a view of the nature of Nature — espoused by Dawkins and Dennett especially — that is more restrictive than the view held by most scientists. Focusing on refuting this more restricted view threatens to push ID onto a path where it will remain tangential and irrelevant to the questions that active scientists pursue and find meaningful.
Moss's example of the new way for science to proceed is taken from the work of philosopher Immanuel Kant. Kant allowed us to have it both ways; Moss said — we can take it as a given that there is an organization in life while at the same time resisting the temptation to try to explain the purpose or first principle of everything. In this way, the "new naturalism" that Moss proposes does not require, presuppose, or even benefit from atheism. In contrast, many in the ID movement seem to be opposed to evolution because Dawkins and Dennett portray it as essential to supporting atheism.
The unspoken position of the IDCs at the conference seemed to be to accept all criticisms of evolutionary theory as evidence that an intelligent agent of some sort was involved in the history of life and in the patterns of similarity and difference that biologists attribute to evolution. However, one of the hallmarks of most scientific meetings was absent — the disagreement among proponents of different explanatory models. There were young-earth creationists presenting papers in breakout sessions who never addressed the discrepancies between their models of recent creation of organisms in their present forms and theistic evolution that Behe has claimed to accept, which would allow descent with modification from common ancestors over long time periods — at least for structures that were not "irreducibly complex", which was how Behe pronounced most of the examples that the ID critics used to rebut his model.
DAIC showed the "big tent" strategy in operation. This approach makes IDC more inclusive in order to increase the impact of the assault on evolutionary theory from a broad base of support. This may also be why details were so often missing from the presentations at the plenary sessions. All the anti-evolutionists in attendance may agree that evolution is bad and that apparent design in the universe is caused by an intelligent agent, but they do not agree on the specifics of time, place, frequency, duration, or intensity of this extranatural intervention. The devil, as they say, is in the details.
Thursday, June 22, 2000
The opening debate was on Thursday night. Stephen Meyer and Michael Shermer shared the stage. Meyer's talk was entitled "What do good scientific theories do?" According to Meyer, they explain data in the natural world and make predictions about the natural world — particularly predictions that are useful for future scientific research. Because explanation is not equivalent to prediction, Meyer argued, historical theories can accomplish only the first task; they can retrodict but not predict. ID also accomplishes the first task: it has explanatory power. Meyer's example was the concept of irreproducible complexity introduced in Behe's discussion of the bacterial flagellum.Meyer went on to claim that ID provides a better explanation than evolutionary theory in several instances. First, Meyer argued that ID provides a better explanation of the origin of "information", in particular the origin of DNA, than does evolution. Next he claimed that ID provides a better explanation of the Cambrian Explosion — the sudden appearance of new phyla in the fossil record 570 million years ago — because new organisms require a new information code. According to Meyer, this situation does not fit a "Darwinian" model, because the mere shuffling of genes is not sufficient to produce this variety (though he provided no support for this assertion). In Meyer's view, the shortcomings of evolutionary models confirm ID by default.
Meyer rehearsed the standard mistaken creationist critiques based on biochemical complexities and specificities of modern organisms, but added an interesting — if misconstrued — discussion of the origin of DNA. Since DNA provides the instruction set for proteins, Meyer asked, what is the causal explanation of the DNA code? Citing Stanley Miller's experiments as proof that the prebiotic atmosphere was unsuitable for sustaining life, Meyer concluded that there was no natural prebiotic source of the information encoded in DNA. Any precursor molecules would be subject to interfering cross-reactions, and the limited time and resources combined with the required sequence specificity (for a fully functioning 100-amino-acid protein) would have precluded de novo synthesis. Meyer tried to apply a version of Dembski's "explanatory filter", arguing that the low probability and the complex specification of the DNA molecule require us to conclude that it had been designed.
The main focus of the rest of Meyer's presentation was the supposed evidence for the design of DNA -- the information content of living things. Meyer argued that natural selection cannot explain the origin of information, because it presupposes a freely replicating system — one that operates on DNA and protein (of course, natural selection is not concerned with, nor does it try to explain, the origin of "information"). Furthermore, Meyer argued that there are no forces in evolutionary theory to explain the sequential order of DNA, apparently because he believes that, according to evolutionary biologists, nucleotide base organization should be random. Of course, in most organisms many repetitive sequences in DNA, noncoding introns ("nonsense" DNA), and "junk" DNA are not constrained by strict sequential relationships. These random elements constitute a very large fraction of the genome.
Meyer constructed a straw man by focusing on DNA and fully functioning proteins. No working evolutionary scientist believes that life originally appeared fully equipped with the present complex DNA and protein repertoire. One leading theory of early life is the RNA world hypothesis, about which, in the question period, Meyer showed that he is absolutely misinformed, falsely claiming that RNA could neither replicate nor make peptide bonds. The question period ended before he could be fully questioned on this topic, but there are several published papers that show that Meyer was attacking strawman arguments about DNA, RNA, and information origin (Zhang and Cech 1997, Wright and Joyce 1997).
Michael Shermer took the stage next. His presentation was more theatrical (complete with a laser pointer that projected the shape of a UFO). He made some very good points, but I do not think that most of the audience was sufficiently engaged by his presentation. Natural selection, Shermer said, preserves gains and eliminates mistakes; "Intelligent Design" assumes that the current function of structures in living things is the same as the original function. He argued that ID is not useful scientifically because it leads to an investigative dead end — the actions of an intelligent designer.
Friday, June 23, 2000
The first plenary session was entitled "Design in the Biological Sciences". Michael Behe spoke first. He read from a prepared text, saying that he has learned that he must be particularly careful in what he says. His main point was that there are irreducibly complex (IC) structures — structures that could not have been produced by numerous successive small changes without loss of function. Natural selection, which Behe restricts to such small, successive changes, would be unable to explain the existence of such structures. His examples of IC structures were the mousetrap — a 5-piece machine that is rendered nonfunctional by the removal of any piece — and the bacterial flagellum — a complicated, molecular "machine" that may be the biochemical equivalent of the mousetrap.Behe next responded to Ken Miller's Finding Darwin's God. He focused on the lac operon — a genetic sequence in E coli bacteria that regulates the production of 3 enzymes necessary for the digestion of lactose. If any component of this multipart system is eliminated, argued Behe, the system becomes nonfunctional Although Kenneth Miller had cited experiments showing that when the one of the lac operon genes — the (-galactosidase gene — is knocked out, bacteria can re-acquire this function, Behe disputed this conclusion, because, he said, it was necessary to generate an artificial system using "intelligent intervention" that added other components to the system before the function could be restored.
Behe's next example of IC was the blood-clotting cascade. Behe illustrated the complexity of this system and claimed that removal of any of the components is highly deleterious and causes the whole process to collapse. Citing research with transgenic organisms, Behe argued that these systems are irreducibly complex, because they contain many parts that must be well coordinated with one another to function — therefore, they could not have arisen by natural selection working through gradual, Darwinian mechanisms.
Next up was Scott Minnich, whose talk focused on the research on the bacterial flagellum. He gave a very nice, purely scientific talk on research in the field, which did not seem to fit in here because it seemed that a substantial part of his talk contradicted the assertion of irreproducible complexity. For example, he discussed the virulence plasmid found in the bacterium that causes bubonic plague, which, as it turns out, contains several genes that are highly homologous to those that code for flagellar proteins. In the plasmid, these genes code for proteins that make up structures that drill holes into host cells and inject them with poison. Here we have an example where one set of genes codes for flagellar proteins, however a homologous subset of those genes codes for an entirely different structure (hole drilling apparatus). In an IC structure, if a single component is removed, the structure loses its specific function. But complex structures need not lose all physiological function when one component is changed. The exaptation of an existing structure — such as occurs in the protein products of the virulence plasmid — to a structure performing a new function — such as the flagellum — is precisely the sort of change evolution would predict. Minnich's example endangers only the straw man position that these cellular structures must preserve their existing functions as their protein composition or sequence is modified.
Ken Miller spoke next, presenting a step-by-step, systematic critique of Behe's argument. First he pointed out, in contrast to the assumptions of IC, that no scientist proposes that complex macromolecular systems spontaneously arose in their currently functioning state. Instead, individual components of the larger system probably had other functions, and, through gene duplication or other mechanisms, they took on new functions. These processes permitted the acquisition of new functions and opportunities to interact with other molecules to provide intermediaries with novel functions.
Miller spent a great deal of time describing how the flagellum might have evolved, providing numerous examples of organisms that illustrate the mechanisms and processes that he proposed. He also gave examples of flagella that have some components missing but still function. The example that made the best impression on the audience was that of eel sperm. The missing components make the flagellum appear nonfunctional, said Miller, but, he reminded the audience, since these sperm are very good at making baby eels, the flagellum clearly must function — despite its having "missing" parts.
Next Miller discussed the Krebs cycle — a series of chemical reactions common to living things that extracts energy from carbohydrate molecules — showing how a variety of organisms use different parts of the cycle for different functions. All the while Miller reminded the audience that according to IC, the loss or alteration of one component from an IC system makes the system nonfunctional. At the same time, he reminded the audience that complex systems evolve by co-opting pre-existing, functioning components to serve new functions in new ways.
Miller also presented a bibliographic search (on Medline) showing that there have been only 2 articles on IC in the peer-reviewed literature since 1966, neither one of which appeared in a peer-reviewed scientific research journal. Finally, he took on the central "commonsense" analogy of IC — the irreducibly complex mousetrap. He demonstrated fully functional 5-part, 4-part, 3-part, 2-part and even 1-part mousetraps, concluding by pointing out how, as in biology, the mousetrap that serves one function can be adapted for others (He cited the mousetrap key chain and the mousetrap tie-tack).
A question-and-answer period followed the presentations. As might be expected, Behe took exception to many of Miller's criticisms, denying that he had ever said the things for which Miller took him to task. This is a dangerous tactic in the digital age when your opponent is armed with a laptop computer. Miller was able to provide precise quotations and citations from Behe's work to support his claims. Behe was backpedaling throughout the entire session, and not many questions were asked of the speakers.
During this session, I (JO) introduced myself as a population geneticist from Rush Medical Center in Chicago and said that I had 3 related observations that led to a practical question. First, my research focuses on the identification of genes responsible for complex autoimmune diseases. Evolutionary theory provides the basis for the genetic algorithms that I use in my research. Second, 2 weeks earlier I had visited a pharmaceutical company that also uses evolutionary algorithms to aid in the identification of different alleles affecting drug-metabolizing enzymes. Third, I recently met a researcher at Marquette University who uses evolutionary algorithms to aid in identification of amino-acid residues critical for function of a very complex protein. My question — an open question to both of the ID proponents — was: As practical people, looking for the fastest, most efficient method to reach our goals., how would Intelligent Design help us in our endeavors? What would ID predict in these different systems?
Behe answered the question by commenting that ID would tell us where to look, and perhaps which systems would be irreducibly complex. I replied that his answer really did not answer my question. In the real world of scientific research, I reiterated, evolutionary theory provides algorithms that suggest how to go about finding what we are looking for; these algorithms are used successfully in many fields — including by pharmaceutical companies that are primarily interested in making money. How would ID provide a superior model for accomplishing these goals? Behe answered by mumbling something about needing to see what algorithms I am using. Then the session was closed.
My question sparked discussion afterwards, and I had opportunity to talk with quite a few different people. The general consensus of these people (with the exception of one oddball who basically contended that we are all de-evolving into the blackness of Hell) was that my question really went to the crux of the issue of whether ID has anything useful to present to the scientific community. Scientific theories not only explain and make sense of our observations, but also provide questions and predictions that support useful and productive research.
The claim that ID only has power to retrodict is an evasive maneuver that may sound nice in a sound bite. But the fact is that a theory that only retrodicts is a scientifically worthless idea that does not merit the title of theory. ID is based entirely on the assumption that when science reaches a stumbling block, the appropriate response is to throw up one's hands, say "I don't understand how this could be put together naturally" and to claim that it was intelligently designed. In this way ID is actually more scientifically bankrupt than young-earth creationism, which at least makes testable predictions. ID is invoked only when regular science gets stuck (for the moment).
Saturday, June 24, 2000
The main event of the final day of the conference was the talk of ID's undisputed star, William Dembski. Much of the presentation was devoted to an exposition of Dembski's method for detecting design — "The Design Inference" (TDI). Dembski had prepared enough material for several presentations, so he was unable to give more than a fleeting description of the details of TDI. Because there was too much material for the format and time allowed, Dembski skipped over numerous details and omitted connections among important ideas. The result was a presentation that appeared disorganized and disjointed — the lasting impression is of a series of symbolic statements that were meant to show the steps in the explanatory filter that Dembski proposes as the basis for TDI. However, Dembski's presentation was so abridged that these formulas were neither well explained nor clearly related to his TDI. RNCSE readers interested in Dembski's method for detecting design should consult Wesley Elsberry's recent review-essay in RNCSE (Elsberry 1999).The second major event on Saturday was a panel discussion entitled "Prospects for Design". The participants were Paul Nelson, Edward Davis, Kelly Smith, and Lenny Moss. Nelson told the audience that the real issue is to provide an argument against methodological naturalism (MN), which he called one of the worst philosophies of science. Nelson characterized MN as absolute rubbish and characterized himself as someone interested in getting at the truth about the world. He said that his purpose was to show the limits of MN, not to set out the future direction of ID.
Nelson provided a definition of MN based on the characterization by the National Academy of Sciences (NAS): "The statements of science must invoke only natural things and processes" (NAS 1998: 42). Nelson's question to the audience was, "Should this be so? Should we separate the natural from the supernatural?" Nelson argued that we should discard the supernatural-natural distinction in favor of the intelligent-natural distinction. We should, Nelson said, institute a research program for intelligent causation — but true to his promise, Nelson did not suggest what such a program would entail.
Most of Nelson's presentation was an exploration of how MN supposedly limits our ability to find out what is true. In Nelson's example, a homicide detective faced with a dead body must consider 4 possible explanations in order to determine the real cause of death. Two of these require no intelligent agent — natural causes and accidents — but the other 2 are caused by the actions of just such an agent — suicide and homicide. According to Nelson, MN would limit the homicide detective's investigation to death by natural causes or accident and would leave out suicide and homicide — both actions of an intelligent agent. In the real world, Nelson argued, even if death were never to occur by suicide and homicide, they would remain causal probabilities — that is, they could occur — and, according to Nelson, if we do not consider homicide and suicide to determine that they do not explain the death we are investigating, then we cannot know for sure that our explanations are true. Unless he considers and rules out the possibility of murder and suicide, the detective cannot be justifiably confident that he has solved the case. Likewise, Nelson argued, we should not exclude intelligent design from the scientific "toolkit".
According to MN, Nelson told the audience, the tools in the scientific toolkit are natural laws (Nelson called them "physical" laws) and chance. Nelson argued that a third tool, intelligent design, belongs in the toolkit of science too. Even if we never need to invoke ID, Nelson told the audience, a naturalistic interpretation of evidence can never be completely justified unless ID is considered and ruled out. Even Darwin lived and worked in an environment with all 3 tools, said Nelson, and it did no harm to his science. Likewise, Nelson assured us, it will do no harm for us to consider ID when the evidence warrants it.
In summary, Nelson argued that science cannot discover what it excludes a priori. If science is a truth-seeking endeavor (as he assumes), then MN belongs on the rubbish heap of history because it limits scientists to a flawed investigative process that fails to include all the explanatory possibilities.
Edward Davis spoke next. He said that he accepts that there is purpose in the universe, although he has concerns about how the issues are framed in the current models of ID. He chose to explore how we understand the meaning of apparent design in Nature through recent research that he has been conducting on the works of Robert Boyle — a 17th-century chemist and natural philosopher best known for his laws about the behavior of gases and his use of controlled experiments.
Although Boyle argued for "design" in the natural world, Davis pointed out that this design represented neither ongoing tinkering by an intelligent agent nor what passed for the contemporary version of the anthropic principle -a philosophy of science that assumed that Nature was constructed benevolently to promote human well-being. Instead, although Boyle was convinced that experimental science would demonstrate the existence of God, he felt that the route to this demonstration was through an understanding of the mechanics of the way things really worked in the natural world. In Boyle's view, God works through the "mechanisms" that show His presence and actions. Boyle felt that the scientific process is short-circuited by teleological explanations, even if there is an ultimate purpose to the universe. He thus insisted on naturalistic explanations for natural phenomena first and foremost whenever possible.
Although he told the audience that he agreed that evidence of purpose is found in the natural world, Davis argued that it is neither appropriate nor productive to look for it in the same ways and places that one looks for evidence of natural processes. Davis told the audience that he believes "in a God who is sovereign over the laws of Nature". However, he noted, the world is not full of items stamped "Made by God"; God is more subtle than that. So the evidence for God's purposes may not be the same physical evidence that we find in natural phenomena that scientists study, say, in the behaviors of gases under pressure or mutation rates.
The most serious problem with ID, Davis told the conference, is that it appears to make the existence of God (the unnamed "intelligent designer") an additional hypothesis to be tested scientifically. However, this runs counter to the central understanding of God in Christian and Jewish traditions. Davis told the audience that the central claim of Christianity, for example, is that we have actually seen God directly, and when we did not like what we saw, we killed him — then he surprised us. Davis said that we need to incorporate the interaction between God and the world into our discourse in this way, not as specific scientific hypotheses about individual events and structures.
The next speaker was Kelley Smith. He presented a "blueprint for respectability" — an outline for how ID could earn itself a place at the scientific table. Smith's remarks are included elsewhere in this issue. In summary, he outlined a program that would turn ID from a fringe idea to a respectable theory in the sciences, along with all the benefits that respectability offers — respect, funds, access to classrooms, and a place in mainstream textbooks and journals. This was the route taken by all successful challengers to the scientific status quo. But he doubted that ID proponents would take his advice.
The last speaker in the panel was Lenny Moss, who argued that the key issue under discussion was the nature of Nature. According to Moss, ID assumed a very narrow notion of Nature, defining its position by its opposition to the viewpoints of a few prominent proponents of philosophical naturalism, such as Richard Dawkins and Daniel Dennett. Moss argued that ID, if it is to be successful, needs to define itself in its own terms, not merely in opposition to what are extreme positions even among natural scientists.
Taking Dawkins and Dennett to task is a good tactical approach, Moss told the conference, for it allows the proponents of ID to press the naturalistic explanation and show where it is in trouble — a debunking strategy. However good a tactical approach it may be to oppose what he called the strict neo-Darwinism of Dawkins and Dennett, Moss said, it is nonetheless a bad strategic approach. That is, to accept that naturalism is restricted to the premises of neo-Darwinism "sells Nature down the river" by restricting naturalism to a particular, limited version of naturalism espoused by Dawkins and Dennett. The most fruitful answer to a dogmatic metaphysics (like that of Dawkins or Dennett), said Moss, is not another dogmatism, but a pluralistic approach. Reacting against a strict neo-Darwinism with a dogmatic approach — whether it is ID or some other dogmatism — leads to bad biology. Instead, Moss argued for a broader perspective for both ID and for naturalism.
In considering the future prospects for ID, there is, Moss said, good news and bad news. As for the good news, Moss argued that science is at a historic juncture — at a new "crisis" in the struggle to resolve our "intuition for life". He traced our understanding of Nature from the 17th century, when science changed its understanding of natural events and organisms as ends unto themselves to a view of these phenomena as the outcome of other natural processes and interactions. This change culminated in the 20th century when, Moss argued we now understand natural events and organisms as only the outcome of natural processes and their interactions. One aspect of this important historic juncture is the Human Genome Project.
Moss told the conference that there are promissory notes that need to be called in — things that biology has promised and not yet delivered. It is time to move beyond the 17th-century view of matter and the physical world to a new scientific understanding that can do justice to the agency of life. This "new naturalism" is one that would allow a pluralistic view of agency in the emergence and direction of life, and one that may make substantial contributions to our understanding of Nature. In reviving a sort of preformationist, vitalistic approach, ID may figure into Moss's "new naturalism".
The bad news for ID is that it seems to be mired in its opposition to a view of the nature of Nature — espoused by Dawkins and Dennett especially — that is more restrictive than the view held by most scientists. Focusing on refuting this more restricted view threatens to push ID onto a path where it will remain tangential and irrelevant to the questions that active scientists pursue and find meaningful.
Moss's example of the new way for science to proceed is taken from the work of philosopher Immanuel Kant. Kant allowed us to have it both ways; Moss said — we can take it as a given that there is an organization in life while at the same time resisting the temptation to try to explain the purpose or first principle of everything. In this way, the "new naturalism" that Moss proposes does not require, presuppose, or even benefit from atheism. In contrast, many in the ID movement seem to be opposed to evolution because Dawkins and Dennett portray it as essential to supporting atheism.
The Big Tent
Throughout the conference there were numerous roundtable discussions, presented papers, and informal discussions over meals and snacks. It was impossible to cover all of these events, and most were not included in the official record of the conference. The sessions we attended resembled the plenary sessions: Some were thoughtful and well-researched presentations of important questions and theoretical perspectives. Others were little more than standard anti-evolutionary fare, concluding that if evolution could not immediately explain some unusual finding or new discover, then ID had to be true by default. But it was also clear that there were a number of very different ideas about what precisely intelligent design entailed.The unspoken position of the IDCs at the conference seemed to be to accept all criticisms of evolutionary theory as evidence that an intelligent agent of some sort was involved in the history of life and in the patterns of similarity and difference that biologists attribute to evolution. However, one of the hallmarks of most scientific meetings was absent — the disagreement among proponents of different explanatory models. There were young-earth creationists presenting papers in breakout sessions who never addressed the discrepancies between their models of recent creation of organisms in their present forms and theistic evolution that Behe has claimed to accept, which would allow descent with modification from common ancestors over long time periods — at least for structures that were not "irreducibly complex", which was how Behe pronounced most of the examples that the ID critics used to rebut his model.
DAIC showed the "big tent" strategy in operation. This approach makes IDC more inclusive in order to increase the impact of the assault on evolutionary theory from a broad base of support. This may also be why details were so often missing from the presentations at the plenary sessions. All the anti-evolutionists in attendance may agree that evolution is bad and that apparent design in the universe is caused by an intelligent agent, but they do not agree on the specifics of time, place, frequency, duration, or intensity of this extranatural intervention. The devil, as they say, is in the details.
References
Elsberry WR. Book review of The Design Inference by William A Dembski. RNCSE 1999 Mar/Apr; 19(2): 32-5.National Academy of Sciences Working Group on Teaching Evolution [NAS]. Teaching About Evolution and the Nature of Science. Washington (DC): National Academy Press, 1998.
Wright MC, Joyce GF. Continuous in vitro evolution of catalytic function. Science 1997; 276: 614-7.
Zhang B, Cech TR. Peptide bond formation by in vitro selected ribozymes. Nature 1997; 390: 96-100.
Can Intelligent Design Become Respectable?
[At the Design and its Critics conference held at Concordia University in Mequon, Wisconsin, June 22–24, 2000,
Kelly C Smith participated in the panel discussion on Prospects for Design. Professor Smith's paper is printed here
with his permission; much of what he says here is covered in more detail in his article "Appealing to ignorance
behind the cloak of ambiguity" in Robert T Pennock's anthology, Intelligent Design and its Critics (Cambridge
[MA]: The MIT Press, 2001).]
I want to thank the organizers of this conference for inviting me here today, although I do rather suspect their motives. This is the very definition of hell for a philosopher — to be invited to a conference, to sit through 2 and a half days of really interesting presentations taking voluminous notes, a lot of which have marginalia attached to them like "no no no!" and "???", and at the very end to be told, "Okay, right! 15 minutes: vent your spleen all you want." Well, there is only so much I can vent. But I am going to try to get together a few basic thoughts I have had and offer them in some kind of coherent form.
What I want to try to do is give you a basic blueprint for respectability. If we make the assumption (and there are lots of people who would question this assumption, but I will make it for the purposes of this talk) that ID theory seriously wishes to become a respectable scientific theory, then I will tell you how to do it. If you follow my 4 simple steps to scientific respectability, you will get what you want: scientific respect, research funds, access to science classrooms, and so on, and so forth. It is actually fairly simple — all you have to do is follow the 4 steps. So what are they?
So can we practice ID theory as a science if we buy this notion of intelligibility? The answer is that it depends on what you mean when you talk about the designer. I have heard speakers here at this conference point out how it is necessary to specify the nature of the designer, and then some people in the audience say that it seems a bit unfair to require ID theorists to come up with a clear notion of what the designer is like. Well, this is not a tangential issue; it is a fundamental issue. An unwillingness to talk about this is going to cripple at the outset any attempt to make ID theory a scientific theory. And here is why. (Although I am not a theologian and I am aware of the fact that this is a horrendously complicated theological dispute, I am going to simplify egregiously.)
There is a large continuum of theories about God's nature, and on this continuum there are 2 basic endpoints. On one endpoint, you have a view of God as an intrinsically mysterious agent. Human reason is simply incapable of penetrating into the mysterious God's motives, mechanisms, and the like. On the other end of the continuum, there is God as a rational God, a God whose motives and mechanisms are analogous to those of human intelligence (a phrase that came up in an earlier talk). In other words, a rational God is a God that we can understand in some important sense of that word.
If we are talking about a rational God, I think that it is perfectly okay, in principle, to include theological hypotheses as part of a scientific theory. Now, for my evolutionist colleagues who are getting uncomfortable at this point, I would like to point out that there are going to be a lot of people out there who are not willing to accept what goes along with making God rational in this sense. But if you do, it is possible to include some kind of theology in scientific theory — Spinoza, for example, had a theological account that is not inconsistent with the sorts of claims scientists would normally want to make. But if you cite a mysterious God, you are inserting a factor in your explanation that is in principle inexplicable.
Paul Nelson just gave you the example of a professor's suddenly getting up and walking around a conference table as something that is not explained. Here is a good example of a fundamental confusion. Intelligibility is not a question of whether or not we have explained something, it is a question of whether or not it is explainable — is it, in principle, subject to explanation? I think someone's getting up and walking around the table is perfectly explainable. There are epistemic problems to be sure — it is not a trivial exercise to explain it. However, it is hardly inexplicable, and that is what makes it fair game for a scientific explanation. (As an aside, I should say that some of the confusion about whether ID theory is testable but false or untestable has to do with equivocal notions about the nature of the designer.)
A rational God has clear, practical consequences for a scientific theory. Suppose you posit a rational God and then assume that God designed the traits of organisms to maximize ________ (you are going to have to fill in the blank because I do not know what your particular rational God would want to maximize; I personally would tend to say something like "adaptiveness within a particular selective environment", but that is just me). Whatever goes in this blank, it seems we can then formulate a null hypothesis and say, "We expect God to be at least as good as a human engineer would be in designing traits to maximize ________." Any trait that seems poorly designed from a human perspective would then represent a prima facie problem for an ID theorist. What you certainly cannot do in this kind of situation is to argue that it is simply a mystery why God created this trait in this particular way, because then all you are doing is reverting to a mysterious God.
I cannot really convince you right now why it is a good idea to buy into intelligibility. I would quickly say something like this, though: the consequences of not buying into this are far worse than you might think. To take what Winston Churchill said about democracy and apply it to neo- Darwinism, "Neo-Darwinism seems like a really bad theory — until you consider the alternatives".
So it seems as though there are 2 alternatives here: either you can institute a thorough, rigorous system of internal critique and try to develop a consensus along some of these issues, or you can fragment into separate groups, each group having a relatively unified approach to these kinds of things. Either will accomplish what I have called "internal critique".
There are lots of reasons to keep the two activities clearly separate. First, it is always easier to be negative than positive. Given that any complicated theory is going to have anomalous data, anybody can find interesting cases to harp on. This does not really prove a whole lot. Second, it is just too tempting to engage in distortions of what your opponent says (straw man arguments). This is particularly true if you believe deeply in what you're saying — this makes it extremely difficult to be fair to your opponent, who you "know" is completely wrong. I do not see a whole lot of evidence, to be perfectly honest with you, that there has been a change in some of these practices since the bad old creationist times. Third, it may very well be that you are implying a false dichotomy. The underlying assumption when you substitute critique for demonstration is that, if my opponent is wrong, then I must be right. But there may well be a third alternative. Suppose it turns out that neo-Darwinism, whatever that means (people define this term in lots of different ways for different purposes), is wrong. It does not necessarily follow that ID theory is right, unless those are the only 2 alternatives, and believe me, there are more. Finally, it draws attention away from a basic practical fact (that it is practical makes it no less important). Nobody is going to abandon an extremely fruitful scientific theory until there is a viable alternative that does as much or more. It is just not going to happen. I have been in a position of espousing a theory on the outside of orthodoxy, and I understand that it can be frustrating, but at some point you have to shift away from whipping up the crowd by complaining about your lot versus the orthodoxy to coming up with a theory that works.
The basic reason for this is pretty simple. We are clever and creative explainers. It is very easy for us to sit in a dark room and convince ourselves, based on a priori principles and data that are already in front of us, that we have the correct explanation. The only way we can really know whether or not our explanation is right is if we make novel predictions and then go out and see if they are met. That is the function of testability. As far as I can tell, ID theory just does not do this. There might be, maybe, some very minimal claims you can make about the heuristic value of ID theory — one of the talks, for example, postulated that perhaps the design heuristic is akin to notions such as beauty in evaluating scientific theories. Even if I were to grant that, this claim does not put ID anywhere close to the status of a developed scientific theory. We do not teach beauty in elementary science classes as a way of talking about scientific theories, and for very good reason. It is, at best, an interesting subtlety you get into when you talk about the philosophical aspects of science. It is not a fundamental theory in itself.
I think that nothing shows the difference between ID theory and its orthodox opponents better than a comparison of professional conferences. If I go to the annual meeting of the Society for the Study of Evolution, and I bring a bunch of graduate students who want to do research in evolution, I can point them in any direction and they can go and find hundreds of seminars going on, each of which has all kinds of evolutionary ideas, testable hypotheses, new methodologies based on evolutionary reasoning. They can go out there, they can find research projects, they can go back to the lab, and they can go to work. This ID conference, on the other hand, really does not have a single session presenting testable hypotheses. There was one that, in a way, sort of, kind of, made allusions to testable consequences, but I can say firsthand that there was nothing discussed in this session that neo-Darwinism had not already predicted. So there is really no practical import to ID theory that I can see.
Now, in case people are tempted to say, "Ah, well, give us some time, we'll figure this out," let me suggest that there clearly are testable consequences right now. Any relatively bright graduate student should be able to sit down with a pencil and a piece of paper and come up with some for you pretty quickly, and then you have got a research project. In case you cannot find anybody like that, allow me to offer your first testable hypothesis. A lot of ID theorists (and again we run into the ambiguity problem) have absolutely no problem accepting the theory of population genetics as a microevolutionary theory. But they do not like to accept macroevolution. They believe that there are certain natural kinds, or species, or whatever, and there are boundaries in between the kinds that cannot be overcome. In other words, population genetics works, but it cannot push allele change past these postulated boundaries between kinds. The existence of such boundaries is not a prediction of population genetics, and there is nothing in population genetic theory that would even lead one to suspect such bounded change. So, if this ID view is correct, there should be populations left and right that meet all the population-genetic criteria predicting evolution, but that are in fact not undergoing evolution. It should be a relatively straightforward job to go out and confirm experimentally the existence of these populations.
Now, let me just insert a caveat here because I worry about having my words taken out of context. The populations you find have to meet all the population genetic criteria. There are cases one could point to that might seem on superficial examination to meet all the criteria, but really do not. I have in mind something like sickle cell trait. When people first discovered sickle cell trait and did population genetics on it, it was a bit of a mystery why the sickle cell allele was so common in the population. People knew that in its homozygous form it was highly deleterious, so they calculated the selection coefficients based on this and said, "This is very strange — there are a lot more of these alleles floating around in the population than we would expect." This puzzle led to an investigation to see what other factors were at work in the population. As it turns out, the sickle cell allele confers an advantage in the heterozygous condition, so people who have only one copy of the sickle cell allele are more resistant to malaria, and in certain parts of the world that is a very good thing. After discovering this, the geneticists adjusted their selection coefficients and re-did the calculations, and it works perfectly. So I am not talking about superficially analyzed populations that appear not to undergo evolutionary change. I am talking about a situation in which you have excellent data on the population genetic variables and they simply do not add up.
I want to thank the organizers of this conference for inviting me here today, although I do rather suspect their motives. This is the very definition of hell for a philosopher — to be invited to a conference, to sit through 2 and a half days of really interesting presentations taking voluminous notes, a lot of which have marginalia attached to them like "no no no!" and "???", and at the very end to be told, "Okay, right! 15 minutes: vent your spleen all you want." Well, there is only so much I can vent. But I am going to try to get together a few basic thoughts I have had and offer them in some kind of coherent form.
What I want to try to do is give you a basic blueprint for respectability. If we make the assumption (and there are lots of people who would question this assumption, but I will make it for the purposes of this talk) that ID theory seriously wishes to become a respectable scientific theory, then I will tell you how to do it. If you follow my 4 simple steps to scientific respectability, you will get what you want: scientific respect, research funds, access to science classrooms, and so on, and so forth. It is actually fairly simple — all you have to do is follow the 4 steps. So what are they?
Step 1: Intelligibility
Well, the first step is a little complicated, but it involves intelligibility. I prefer not to talk about naturalism, but rather intelligibility. I think the one thing that scientists cannot compromise on — one of their most fundamental philosophical principles — is a commitment to intelligible causal factors. That is to say, they will not accept, in principle, explanations that make reference to causal factors that cannot be explained by human reason. Why does this matter? Well, it matters because it makes a big difference as to whether or not ID theory can be done within the context of science. I should add, by the way, that I fully grant that this is, in some sense, a philosophical assumption. It may be wrong. If you guys would like an admission that any of your favorite versions of creationism or ID theory could perhaps be correct, you have it from me. As a representative of the scientific orthodoxy, I will admit that they could, perhaps, be correct — but that is not a sufficient reason to believe them.So can we practice ID theory as a science if we buy this notion of intelligibility? The answer is that it depends on what you mean when you talk about the designer. I have heard speakers here at this conference point out how it is necessary to specify the nature of the designer, and then some people in the audience say that it seems a bit unfair to require ID theorists to come up with a clear notion of what the designer is like. Well, this is not a tangential issue; it is a fundamental issue. An unwillingness to talk about this is going to cripple at the outset any attempt to make ID theory a scientific theory. And here is why. (Although I am not a theologian and I am aware of the fact that this is a horrendously complicated theological dispute, I am going to simplify egregiously.)
There is a large continuum of theories about God's nature, and on this continuum there are 2 basic endpoints. On one endpoint, you have a view of God as an intrinsically mysterious agent. Human reason is simply incapable of penetrating into the mysterious God's motives, mechanisms, and the like. On the other end of the continuum, there is God as a rational God, a God whose motives and mechanisms are analogous to those of human intelligence (a phrase that came up in an earlier talk). In other words, a rational God is a God that we can understand in some important sense of that word.
If we are talking about a rational God, I think that it is perfectly okay, in principle, to include theological hypotheses as part of a scientific theory. Now, for my evolutionist colleagues who are getting uncomfortable at this point, I would like to point out that there are going to be a lot of people out there who are not willing to accept what goes along with making God rational in this sense. But if you do, it is possible to include some kind of theology in scientific theory — Spinoza, for example, had a theological account that is not inconsistent with the sorts of claims scientists would normally want to make. But if you cite a mysterious God, you are inserting a factor in your explanation that is in principle inexplicable.
Paul Nelson just gave you the example of a professor's suddenly getting up and walking around a conference table as something that is not explained. Here is a good example of a fundamental confusion. Intelligibility is not a question of whether or not we have explained something, it is a question of whether or not it is explainable — is it, in principle, subject to explanation? I think someone's getting up and walking around the table is perfectly explainable. There are epistemic problems to be sure — it is not a trivial exercise to explain it. However, it is hardly inexplicable, and that is what makes it fair game for a scientific explanation. (As an aside, I should say that some of the confusion about whether ID theory is testable but false or untestable has to do with equivocal notions about the nature of the designer.)
A rational God has clear, practical consequences for a scientific theory. Suppose you posit a rational God and then assume that God designed the traits of organisms to maximize ________ (you are going to have to fill in the blank because I do not know what your particular rational God would want to maximize; I personally would tend to say something like "adaptiveness within a particular selective environment", but that is just me). Whatever goes in this blank, it seems we can then formulate a null hypothesis and say, "We expect God to be at least as good as a human engineer would be in designing traits to maximize ________." Any trait that seems poorly designed from a human perspective would then represent a prima facie problem for an ID theorist. What you certainly cannot do in this kind of situation is to argue that it is simply a mystery why God created this trait in this particular way, because then all you are doing is reverting to a mysterious God.
I cannot really convince you right now why it is a good idea to buy into intelligibility. I would quickly say something like this, though: the consequences of not buying into this are far worse than you might think. To take what Winston Churchill said about democracy and apply it to neo- Darwinism, "Neo-Darwinism seems like a really bad theory — until you consider the alternatives".
Step 2: Internal Critique
The second step has to do with internal critique. You really can learn a lot about somebody by the people with whom they choose to associate. ID theory wants to be a "big tent" movement, but to fail to critique highly divergent arguments of colleagues who happen to share the same conclusion is tacitly to accept them. ID theory is not going to be a scientific discipline until it takes a clear stand on some major methodological issues. You simply cannot have a scientific discipline that talks about evolution but does not take a clear stand on the age of the earth or on common descent with modification! A scientific discipline shares, at least to some large extent, a certain common core of questions and methodologies. ID theory has no core methodology or theoretical commitments, and thus it is not yet a discipline (scientific or otherwise). Perhaps this can be remedied, but not as long some of your adherents persist in making the ambiguity of your own positions a defensive virtue, as when a critique is deflected with, "Well, you know, we don't all say that." If ID theorists themselves do not take a consistent stand, they are certainly not entitled to complain about the imprecision of their critics over the very same points!So it seems as though there are 2 alternatives here: either you can institute a thorough, rigorous system of internal critique and try to develop a consensus along some of these issues, or you can fragment into separate groups, each group having a relatively unified approach to these kinds of things. Either will accomplish what I have called "internal critique".
Step 3: External Critique
The third step has to do with external critique — with stepping away from over-reliance on critiquing your opponents. When I teach basic philosophy classes, I have my students write argumentative papers. I want them to understand that critical ability is extremely important — it is something that they hone in a philosophy class, if nothing else. But I also want them to understand that there is a fundamental difference between critiquing your opponent and demonstrating your own position. This is a fundamental distinction that ID theorists need to take more seriously.There are lots of reasons to keep the two activities clearly separate. First, it is always easier to be negative than positive. Given that any complicated theory is going to have anomalous data, anybody can find interesting cases to harp on. This does not really prove a whole lot. Second, it is just too tempting to engage in distortions of what your opponent says (straw man arguments). This is particularly true if you believe deeply in what you're saying — this makes it extremely difficult to be fair to your opponent, who you "know" is completely wrong. I do not see a whole lot of evidence, to be perfectly honest with you, that there has been a change in some of these practices since the bad old creationist times. Third, it may very well be that you are implying a false dichotomy. The underlying assumption when you substitute critique for demonstration is that, if my opponent is wrong, then I must be right. But there may well be a third alternative. Suppose it turns out that neo-Darwinism, whatever that means (people define this term in lots of different ways for different purposes), is wrong. It does not necessarily follow that ID theory is right, unless those are the only 2 alternatives, and believe me, there are more. Finally, it draws attention away from a basic practical fact (that it is practical makes it no less important). Nobody is going to abandon an extremely fruitful scientific theory until there is a viable alternative that does as much or more. It is just not going to happen. I have been in a position of espousing a theory on the outside of orthodoxy, and I understand that it can be frustrating, but at some point you have to shift away from whipping up the crowd by complaining about your lot versus the orthodoxy to coming up with a theory that works.
Step 4: Novel, Testable Hypotheses
And that gives me a segue into my last and probably most important step, that ID theory really has to start generating novel, testable hypotheses (and then testing them). Now, I'm a philosopher, so I am perfectly aware of all the dilemmas that arise if you try to make testability some sort of touchstone for science. I am not saying that. I am not a logical positivist. But I think it is clearly true, however you want to characterize it, that testability is a critically important element of successful scientific theories. Therefore, if ID theory is going to be a successful scientific theory, it must generate testable hypothesis — and note here I am also saying testable hypotheses (I am not talking about the theory's being testable itself. That is a can of worms I would rather not open right now).The basic reason for this is pretty simple. We are clever and creative explainers. It is very easy for us to sit in a dark room and convince ourselves, based on a priori principles and data that are already in front of us, that we have the correct explanation. The only way we can really know whether or not our explanation is right is if we make novel predictions and then go out and see if they are met. That is the function of testability. As far as I can tell, ID theory just does not do this. There might be, maybe, some very minimal claims you can make about the heuristic value of ID theory — one of the talks, for example, postulated that perhaps the design heuristic is akin to notions such as beauty in evaluating scientific theories. Even if I were to grant that, this claim does not put ID anywhere close to the status of a developed scientific theory. We do not teach beauty in elementary science classes as a way of talking about scientific theories, and for very good reason. It is, at best, an interesting subtlety you get into when you talk about the philosophical aspects of science. It is not a fundamental theory in itself.
I think that nothing shows the difference between ID theory and its orthodox opponents better than a comparison of professional conferences. If I go to the annual meeting of the Society for the Study of Evolution, and I bring a bunch of graduate students who want to do research in evolution, I can point them in any direction and they can go and find hundreds of seminars going on, each of which has all kinds of evolutionary ideas, testable hypotheses, new methodologies based on evolutionary reasoning. They can go out there, they can find research projects, they can go back to the lab, and they can go to work. This ID conference, on the other hand, really does not have a single session presenting testable hypotheses. There was one that, in a way, sort of, kind of, made allusions to testable consequences, but I can say firsthand that there was nothing discussed in this session that neo-Darwinism had not already predicted. So there is really no practical import to ID theory that I can see.
Now, in case people are tempted to say, "Ah, well, give us some time, we'll figure this out," let me suggest that there clearly are testable consequences right now. Any relatively bright graduate student should be able to sit down with a pencil and a piece of paper and come up with some for you pretty quickly, and then you have got a research project. In case you cannot find anybody like that, allow me to offer your first testable hypothesis. A lot of ID theorists (and again we run into the ambiguity problem) have absolutely no problem accepting the theory of population genetics as a microevolutionary theory. But they do not like to accept macroevolution. They believe that there are certain natural kinds, or species, or whatever, and there are boundaries in between the kinds that cannot be overcome. In other words, population genetics works, but it cannot push allele change past these postulated boundaries between kinds. The existence of such boundaries is not a prediction of population genetics, and there is nothing in population genetic theory that would even lead one to suspect such bounded change. So, if this ID view is correct, there should be populations left and right that meet all the population-genetic criteria predicting evolution, but that are in fact not undergoing evolution. It should be a relatively straightforward job to go out and confirm experimentally the existence of these populations.
Now, let me just insert a caveat here because I worry about having my words taken out of context. The populations you find have to meet all the population genetic criteria. There are cases one could point to that might seem on superficial examination to meet all the criteria, but really do not. I have in mind something like sickle cell trait. When people first discovered sickle cell trait and did population genetics on it, it was a bit of a mystery why the sickle cell allele was so common in the population. People knew that in its homozygous form it was highly deleterious, so they calculated the selection coefficients based on this and said, "This is very strange — there are a lot more of these alleles floating around in the population than we would expect." This puzzle led to an investigation to see what other factors were at work in the population. As it turns out, the sickle cell allele confers an advantage in the heterozygous condition, so people who have only one copy of the sickle cell allele are more resistant to malaria, and in certain parts of the world that is a very good thing. After discovering this, the geneticists adjusted their selection coefficients and re-did the calculations, and it works perfectly. So I am not talking about superficially analyzed populations that appear not to undergo evolutionary change. I am talking about a situation in which you have excellent data on the population genetic variables and they simply do not add up.
The Road Ahead
In conclusion: Personally, I find it highly unlikely that my advice is actually going to be put into effect. The fact that I am here means that I am an optimist about these kinds of things. But I strongly suspect, despite what some speakers have said, that there are a priori but unspoken commitments that people here are just not willing to violate. In particular, I think that there are a lot of people here who are unwilling to accept the fundamental philosophical commitment science must make to intelligible causal factors (theological or otherwise). To do so would open a big can of theological worms that a lot of people do not want to get into, and I understand why not. And lastly, I do not have a lot of faith, to use a loaded word, that people who take ID theory seriously are actually going to be able to generate novel, testable hypotheses based on their beliefs. However, I am struggling to remain open-minded, and I welcome any efforts anyone wants to produce along these lines.Intelligent Design in the Classroom?
[At the Design and its Critics conference held at Concordia University in Mequon, Wisconsin, June 22-24, 2000, Kenneth Miller (Brown University) was the commentator at the plenary session on Design in the Public School Science Classroom. The speakers were David DeWolf (Gonzaga University Law School) and Stephen Meyer (Whitworth College and the Discovery Institute), Warren A Nord (University of North Carolina at Chapel Hill), and Ronald Numbers (University of Wisconsin at Madison). The following excerpt from Professor Miller's extemporaneous comments is printed here with his permission.]
I was surprised to hear Professor DeWolf fundamentally confuse two legal issues. He talked about the acceptance of scientific evidence by the Supreme Court. And he said that the Court's acceptance of scientific evidence has changed from requiring that the scientific evidence be the prevailing scientific view to simply allowing any method that sort of follows the methods and procedures of science. The interesting thing about this assertion is that it has nothing to do with the suitability of scientific teaching in the classroom; it simply has to do with the taking of testimony in tort cases, in lawsuits. And it was designed to allow the broadest possible interpretation to come in, so that a jury could judge the evidence in a court case. And it seems to me that what is admissible as authentic science in education is quite a bit different from what testimony is allowable in a tort case, and I do not understand how someone as experienced in the law as Professor DeWolf could confuse the two of those.
It was pointed out that there is another Supreme Court decision related to viewpoint discrimination, so called, and I clearly heard the first pair of speakers [DeWolf and Meyer] implying that the exclusion of intelligent design from the science classroom was an example of viewpoint discrimination, thus once again confusing important legal issues. The "viewpoint discrimination" in question had to do with viewpoints allowed by school-funded groups, not viewpoints in the classroom curriculum. As a scientist, I would argue that the entire scientific enterprise is, in fact, an enterprise of viewpoint discrimination. And what I mean by that is that there are indeed viewpoints we discriminate against in science — meaning that we rule them out — including things like the notion of a flat earth, the notion of a geocentric or earth-centered universe, and purely spiritual theories of disease that suggest that the black plague, cancer, and tuberculosis were due to spiritual defects. Koch, Pasteur, and others advocated a germ theory of disease that explained those quite nicely. Viewpoints to the contrary we do indeed discriminate against, because we regard them as being unscientific and in many cases disproved.
One of the tests put forward by Dr Meyer of whether or not intelligent design theory was appropriate for the classroom, and I think I have this right, was how many scientists take the theory seriously. And clearly, he felt that if a sufficient number do take it seriously, then intelligent design theory should be put in the classroom. Now the interesting thing about that is, as Professor Numbers pointed out, is that when you do systematic searches for the number of papers on intelligent design theory or irreducible complexity that have appeared in the scientific literature, the number that usually comes up is 0. And what this suggests is that these points of view have not made any sort of case in the scientific community.
Meyer then said, well, even if not many scientists take it seriously, the important thing is that these are "controversial" issues. These are issues that are sufficiently controversial that they have drawn 300 of us here; and if there is legitimate controversy, and this is a legitimate controversy, you therefore ought to teach the controversy. Now, I point out that if we had a conference somewhere else, on astrology, we could likely draw many more than 300 people to it. Nonetheless, we would not propose that, therefore, we should teach astrology as an alternative to astronomy. We also do not propose that our medical schools should include the inclusion of Christian Science faith healing as an alternative to scientific medicine.
Incidentally, I heartily endorse Warren Nord's call for courses in comparative religion at the high school level. Religious studies are very important at the university level; I think that they are a fundamental part of the liberal education. He and I stand foursquare together on that one, and I think that it would be very important to do exactly the same thing at the high school level. But again, we would not say that because some people are witches and practice witchcraft, we should promote an artificial equivalence of witchcraft to established religions. And for that matter, we should not — merely because there is controversy in the minds of some — equate Holocaust denial to the authentic history of the Holocaust in the World War II era. And I do not think that anybody here would advocate that. The very existence of a controversy is not sufficient reason to teach it, when we think that controversy has no standing.
Finally, and this is really my last comment, how does new science actually find its way into the scientific classroom? Science changes over time. Scientific textbooks are constantly rewritten. New discoveries get in them time after time after time. In fact, today, as many of you know, the end of the initial phase of the Human Genome Project has just been announced by Celera and by the National Institutes of Health. That announcement, I assure you, is going right into every textbook that every author is in the process of writing or imagining.
So how does new science get into the textbook? The answer is, it gets in by winning the scientific consensus. When you decide what should be presented in the classroom, what you want to present in terms of astronomy or earth science or chemistry, is the scientific consensus on a point of view. That consensus should never be taught dogmatically; it should always be taught as tentative and subject to revision, because all science, including evolution, is tentative and subject to revision. But the fact of the matter is the way these new things get in is not by an act of Congress, not by an act of the state legislature, not even by an act of the state board of education. Rather, they get into the classroom, into the curriculum, and into textbooks by winning the battle for the scientific consensus.
And it is in the culture of science — the American Astronomical Society, the Geophysical Union, the American Society for Biochemistry, the American Society for Cell Biology (to which I belong) — that new ideas have to stand or fall. Bad science is routinely filtered out. Science that wins is not always correct, but it certainly has the scientific consensus behind it. And therefore, what I would urge the advocates of intelligent design to do is the sorts of things that real scientists do, and that is to forswear political action. Do not petition legislatures or state school boards, but simply to show up at scientific meetings, present papers, and argue the case in front of other scientists. Science is an open community, an open society, and if you win the scientific consensus, or even if you get a strong minority view, you will have papers, you will have peer-reviewed publications, you will have reasonable grounds, and you will begin to convince people.
As it turns out, however, the strategies that have been taken just in the last year against evolution have been in an entirely different direction: they have sought the protection of government. What I mean by that is that by acting through the government, the intelligent design movement has achieved temporary success in Louisiana, and limited success in Oklahoma, in putting disclaimers about evolution inside textbooks. Other movements have succeeded in getting state boards of education to remove evolution from the science curriculum in Kansas and also in Illinois. Illinois nobody noticed, but it certainly happened there, and similar moves are under way in a variety of other states. And what bothers me as an educator is to see people basically forswearing the scientific community as a venue in which to advocate what they claim are scientific ideas and instead choosing the agencies of government, sort of jumping around building a nonscientific consensus to get these ideas in the classroom.
Thomas Jefferson once observed that "Error alone requires the assistance of government. The truth can stand on its own." I think that is a good way to put my point.
I was surprised to hear Professor DeWolf fundamentally confuse two legal issues. He talked about the acceptance of scientific evidence by the Supreme Court. And he said that the Court's acceptance of scientific evidence has changed from requiring that the scientific evidence be the prevailing scientific view to simply allowing any method that sort of follows the methods and procedures of science. The interesting thing about this assertion is that it has nothing to do with the suitability of scientific teaching in the classroom; it simply has to do with the taking of testimony in tort cases, in lawsuits. And it was designed to allow the broadest possible interpretation to come in, so that a jury could judge the evidence in a court case. And it seems to me that what is admissible as authentic science in education is quite a bit different from what testimony is allowable in a tort case, and I do not understand how someone as experienced in the law as Professor DeWolf could confuse the two of those.
It was pointed out that there is another Supreme Court decision related to viewpoint discrimination, so called, and I clearly heard the first pair of speakers [DeWolf and Meyer] implying that the exclusion of intelligent design from the science classroom was an example of viewpoint discrimination, thus once again confusing important legal issues. The "viewpoint discrimination" in question had to do with viewpoints allowed by school-funded groups, not viewpoints in the classroom curriculum. As a scientist, I would argue that the entire scientific enterprise is, in fact, an enterprise of viewpoint discrimination. And what I mean by that is that there are indeed viewpoints we discriminate against in science — meaning that we rule them out — including things like the notion of a flat earth, the notion of a geocentric or earth-centered universe, and purely spiritual theories of disease that suggest that the black plague, cancer, and tuberculosis were due to spiritual defects. Koch, Pasteur, and others advocated a germ theory of disease that explained those quite nicely. Viewpoints to the contrary we do indeed discriminate against, because we regard them as being unscientific and in many cases disproved.
One of the tests put forward by Dr Meyer of whether or not intelligent design theory was appropriate for the classroom, and I think I have this right, was how many scientists take the theory seriously. And clearly, he felt that if a sufficient number do take it seriously, then intelligent design theory should be put in the classroom. Now the interesting thing about that is, as Professor Numbers pointed out, is that when you do systematic searches for the number of papers on intelligent design theory or irreducible complexity that have appeared in the scientific literature, the number that usually comes up is 0. And what this suggests is that these points of view have not made any sort of case in the scientific community.
Meyer then said, well, even if not many scientists take it seriously, the important thing is that these are "controversial" issues. These are issues that are sufficiently controversial that they have drawn 300 of us here; and if there is legitimate controversy, and this is a legitimate controversy, you therefore ought to teach the controversy. Now, I point out that if we had a conference somewhere else, on astrology, we could likely draw many more than 300 people to it. Nonetheless, we would not propose that, therefore, we should teach astrology as an alternative to astronomy. We also do not propose that our medical schools should include the inclusion of Christian Science faith healing as an alternative to scientific medicine.
Incidentally, I heartily endorse Warren Nord's call for courses in comparative religion at the high school level. Religious studies are very important at the university level; I think that they are a fundamental part of the liberal education. He and I stand foursquare together on that one, and I think that it would be very important to do exactly the same thing at the high school level. But again, we would not say that because some people are witches and practice witchcraft, we should promote an artificial equivalence of witchcraft to established religions. And for that matter, we should not — merely because there is controversy in the minds of some — equate Holocaust denial to the authentic history of the Holocaust in the World War II era. And I do not think that anybody here would advocate that. The very existence of a controversy is not sufficient reason to teach it, when we think that controversy has no standing.
Finally, and this is really my last comment, how does new science actually find its way into the scientific classroom? Science changes over time. Scientific textbooks are constantly rewritten. New discoveries get in them time after time after time. In fact, today, as many of you know, the end of the initial phase of the Human Genome Project has just been announced by Celera and by the National Institutes of Health. That announcement, I assure you, is going right into every textbook that every author is in the process of writing or imagining.
So how does new science get into the textbook? The answer is, it gets in by winning the scientific consensus. When you decide what should be presented in the classroom, what you want to present in terms of astronomy or earth science or chemistry, is the scientific consensus on a point of view. That consensus should never be taught dogmatically; it should always be taught as tentative and subject to revision, because all science, including evolution, is tentative and subject to revision. But the fact of the matter is the way these new things get in is not by an act of Congress, not by an act of the state legislature, not even by an act of the state board of education. Rather, they get into the classroom, into the curriculum, and into textbooks by winning the battle for the scientific consensus.
And it is in the culture of science — the American Astronomical Society, the Geophysical Union, the American Society for Biochemistry, the American Society for Cell Biology (to which I belong) — that new ideas have to stand or fall. Bad science is routinely filtered out. Science that wins is not always correct, but it certainly has the scientific consensus behind it. And therefore, what I would urge the advocates of intelligent design to do is the sorts of things that real scientists do, and that is to forswear political action. Do not petition legislatures or state school boards, but simply to show up at scientific meetings, present papers, and argue the case in front of other scientists. Science is an open community, an open society, and if you win the scientific consensus, or even if you get a strong minority view, you will have papers, you will have peer-reviewed publications, you will have reasonable grounds, and you will begin to convince people.
As it turns out, however, the strategies that have been taken just in the last year against evolution have been in an entirely different direction: they have sought the protection of government. What I mean by that is that by acting through the government, the intelligent design movement has achieved temporary success in Louisiana, and limited success in Oklahoma, in putting disclaimers about evolution inside textbooks. Other movements have succeeded in getting state boards of education to remove evolution from the science curriculum in Kansas and also in Illinois. Illinois nobody noticed, but it certainly happened there, and similar moves are under way in a variety of other states. And what bothers me as an educator is to see people basically forswearing the scientific community as a venue in which to advocate what they claim are scientific ideas and instead choosing the agencies of government, sort of jumping around building a nonscientific consensus to get these ideas in the classroom.
Thomas Jefferson once observed that "Error alone requires the assistance of government. The truth can stand on its own." I think that is a good way to put my point.
Evolution: How Does It Fare in State K–12 Science Standards?
"Accountability" has been the buzzword in public education for a decade or more. As a consequence, there has been much activity in writing curriculum standards — documents that list what students are expected to know at various grade levels from kindergarten through high school. In late 1997, I was asked by the Thomas B Fordham Foundation to assess the quality of the 36 state science standards then in existence. My report was published in March 1998 (Lerner 1998a) and summarized in this journal shortly thereafter (Lerner 1998b)
Things moved fast after that. By late 1999, so many state standards had been published, revised, or rewritten that a new standards review was prepared for publication in January 2000. By that time, 49 states had science standards. The 50th state, Iowa, does not publish any of its curriculum standards.
In the course of these studies of science standards, it became clear that evolution was a touchy topic, as evidenced by the treatment to which it was subjected in not a few states. It also became clear, moreover, that I had been quite wrong in what I had written in RNCSE in 1998:
It is perhaps repeating the obvious to note that proper teaching of evolution is crucial to decent instruction in the life sciences, for which it is the central organizing principle. Readers of this journal will understand why proper teaching of evolution is so important to science instruction in general as well as to the historical sciences — biology, geology, and cosmology — in particular. With this in mind, I constructed a list of things students ought to learn about evolution as they move from the primary grades (for example, offspring are similar to but not exactly like their parents) through the middle grades (for example, variability among individuals of a species leads to differential survivability in a given environment) to the high-school grades, where a comprehensive, explicit treatment of evolution across all aspects of the biological sciences is appropriate (Gross 2000).
In responding to creationist pressures to obscure or eliminate evolution from their standards, some states have used one or more ploys. The most common are these:
In the absence of such an evaluation, it would be easy — and wrong — to guess that the states treating evolution poorly are mainly in the Bible Belt. There is indeed a concentration of poor performance in those states, but the reality is more complex. North Carolina, South Carolina, and Indiana, on the one hand, have standards that treat evolution excellently, and Louisiana and Texas squeak by with very mediocre but acceptable treatments. Maine, New Hampshire, Wisconsin, and Illinois, on the other hand, have poor-to-bad standards. Good science education is not simply a geographical issue. This is important, because it is a snobbish as well as damaging misconception to shrug one's shoulders and write off the inhabitants of this or that region as incorrigible or ineducable.
The good news is that 31 states — just under one-third — achieved passing grades. But we should not be too sanguine about this. Given the abundance of educational models and the wide variety of approaches to excellence that they offer, there is no reason for any state to do less well than the 6 that achieved perfect scores and the 3 others that came close.
Fortunately, the activity in standards writing and revision has not flagged; many states are busy with improvements. Arizona and New Mexico have only recently fought off creationist attempts to remove evolution from their state standards. As is well known, the voters of Kansas have unceremoniously dumped enough creationists from their state board of education to give strong expectations that Dorothy will soon return from Oz. And there are signs of constructive activity in other poorly rated states as well. On the other hand, the most recent changes in Pennsylvania's proposed science education standards weakened the presence of evolution by introducing inappropriate qualifiers and "hedges" in several sections.
This is not to say unbridled optimism is warranted. Creationism has repeatedly waxed and waned over the United States ever since the notorious Scopes trial of 1925, and will doubtless continue to do so. In particular, the "intelligent-design" creationists are making a vigorous and well-funded effort to influence public-school science teaching at every level. To date their successes have been limited, but they seem to be gradually shouldering out the more traditional but less sophisticated young-earth creationists who, up to the present, have had much more influence. Nevertheless, most young people in the United States have a fair chance to learn biology, and by extension, the other sciences as well.
[Fordham Foundation publications cited below are available on the Internet at http://www.edexcellence.net; single free copies may be obtained by calling the toll-free number 888-823-7474.]
Things moved fast after that. By late 1999, so many state standards had been published, revised, or rewritten that a new standards review was prepared for publication in January 2000. By that time, 49 states had science standards. The 50th state, Iowa, does not publish any of its curriculum standards.
In the course of these studies of science standards, it became clear that evolution was a touchy topic, as evidenced by the treatment to which it was subjected in not a few states. It also became clear, moreover, that I had been quite wrong in what I had written in RNCSE in 1998:
Moreover, except for the issues surrounding the teaching of evolution that arise in a relatively small number of states, the sciences do not seem to be plagued with the political-ideological infighting concerning content that characterizes some of the other areas, notably history and English literature.Indeed, politics had impinged on instruction in most if not all subjects taught in the schools, science not excepted. This was made explicit in two recent publications which reviewed such political pressures throughout the curriculum (Gross 2000; Levitt 1999). We therefore resolved to make a special study focused on the treatment of evolution and the consequences thereof for science instruction in general. This study (Lerner 2000) was published in September 2000.
It is perhaps repeating the obvious to note that proper teaching of evolution is crucial to decent instruction in the life sciences, for which it is the central organizing principle. Readers of this journal will understand why proper teaching of evolution is so important to science instruction in general as well as to the historical sciences — biology, geology, and cosmology — in particular. With this in mind, I constructed a list of things students ought to learn about evolution as they move from the primary grades (for example, offspring are similar to but not exactly like their parents) through the middle grades (for example, variability among individuals of a species leads to differential survivability in a given environment) to the high-school grades, where a comprehensive, explicit treatment of evolution across all aspects of the biological sciences is appropriate (Gross 2000).
In responding to creationist pressures to obscure or eliminate evolution from their standards, some states have used one or more ploys. The most common are these:
- The standards include many of the central principles of evolution — usually briefly — but the word evolution is carefully avoided. Inaccurate and misleading euphemisms such as "change over time" are used instead of the "E-word."
- Biological evolution is simply ignored. Geological evolution, the history of the solar system, and cosmology may well be treated, often even employing the word evolution. Fossils are sometimes mentioned, but only in the context of geology, not biology.
- Evolution of plants and animals is treated to some degree but human evolution is ignored.
- All scientific discussions that imply an old earth or universe are deleted. Kansas is the only state to do this completely, but Mississippi, Tennessee, and West Virginia come close.
- Creationist jargon is used. In Alabama, all textbooks are required to carry a disclaimer that calls evolution "controversial" and labels it "a theory, not a fact." The disclaimer also cites a number of other standard creationist ploys. The details of this approach are discussed below.
- Some or all of the historical sciences are treated lightly but no attempt is made to elucidate the connections among them.
- Is the "E-word used where appropriate? (0–20 points)
- Is biological evolution treated properly? (0–40 points)
- Is human evolution treated? (0–10 points)
- Is geological evolution treated? 0–20 points)
- Is cosmology treated? (0–10 points)
- Are the connections among the historical sciences treated? (0–10 points)
- Is creationist jargon used? (-20–0 points)
- Is a textbook disclaimer mandated? (-25–0 points)
Table I: Distribution of Grades For Treatment of Evolution |
||||||
| Grade | A | B | C | D | F | F-minus |
| Number of States | 9 | 15 | 7 | 6 | 12 | 1 |
| States | CA, CT, IN, NJ, NC, RI, SC, DE, HI | CO, MN, VT, WA, MI, AZ, ID, MA, MO, MT, PA, OR, SD, UT, DC | MD, NM, NV, NY, NE, LA, TX | AR, KY, WI, VA, AK, IL | WY, ME, OH, OK, NH, FL, AL, ND, GA, MS, TN, WV | KS |
The good news is that 31 states — just under one-third — achieved passing grades. But we should not be too sanguine about this. Given the abundance of educational models and the wide variety of approaches to excellence that they offer, there is no reason for any state to do less well than the 6 that achieved perfect scores and the 3 others that came close.
Fortunately, the activity in standards writing and revision has not flagged; many states are busy with improvements. Arizona and New Mexico have only recently fought off creationist attempts to remove evolution from their state standards. As is well known, the voters of Kansas have unceremoniously dumped enough creationists from their state board of education to give strong expectations that Dorothy will soon return from Oz. And there are signs of constructive activity in other poorly rated states as well. On the other hand, the most recent changes in Pennsylvania's proposed science education standards weakened the presence of evolution by introducing inappropriate qualifiers and "hedges" in several sections.
This is not to say unbridled optimism is warranted. Creationism has repeatedly waxed and waned over the United States ever since the notorious Scopes trial of 1925, and will doubtless continue to do so. In particular, the "intelligent-design" creationists are making a vigorous and well-funded effort to influence public-school science teaching at every level. To date their successes have been limited, but they seem to be gradually shouldering out the more traditional but less sophisticated young-earth creationists who, up to the present, have had much more influence. Nevertheless, most young people in the United States have a fair chance to learn biology, and by extension, the other sciences as well.
[Fordham Foundation publications cited below are available on the Internet at http://www.edexcellence.net; single free copies may be obtained by calling the toll-free number 888-823-7474.]
References
Gross P. Politicizing Science Education. Washington (DC): The Thomas B. Fordham Foundation, 2000.Lerner LR. State Science Standards: An Appraisal of Science Standards In 36 States. Washington (DC): The Thomas B Fordham Foundation, 1998a.
Lerner LR. K-12 science standards, state by state, Reports of the National Center for Science Education 1998b Jan/Feb; 18(1): 25-6.
Lerner LR. The State of State Standards 2000. Washington (DC): The Thomas B Fordham Foundation, 2000.
Levitt N. Prometheus Bedeviled, New Brunswick (NJ): Rutgers University Press, 1999.
RNCSE 20 (5)
Articles available online are listed below.
Rodney LeVake Loses Appeal
Rodney LeVake has again failed in his effort to argue that he had free exercise, free speech, and due process rights to teach "evidence against evolution". On May 8, 2001, the Minnesota Appeals Court supported the summary judgment dismissal decision of the Minnesota District Court of last year (see RNCSE 2000; 20 [1-2]: 13-14).
Regarding the free exercise of religion claim, the Appeals Court wrote:
Regarding the free exercise of religion claim, the Appeals Court wrote:
It is unclear on what basis LeVake argues that his right to free exercise of religion was violated. LeVake does not contend that respondents prohibited him from practicing the religion of his choice. He does not assert that respondents demanded that he refrain from practicing his religion outside of the scope of his duties as a public school teacher in order to retain his teaching position, and he does not assert that the curriculum requirements incidentally infringed on his religious practice.Regarding the free speech argument, the Court supported the right of the district to determine curriculum, a position supported with abundant case law:
The classroom is a "marketplace of ideas," and academic freedom should be safeguarded. But LeVake, in his role as a public school teacher rather than as a private citizen, wanted to discuss the criticisms of evolution. LeVake's position paper established that he does not believe the theory of evolution is credible. Further, LeVake's proposed method of teaching evolution is in direct conflict with respondents' curriculum requirements. Accordingly, the established curriculum and LeVake's responsibility as a public school teacher to teach evolution in the manner prescribed by the curriculum overrides his First Amendment rights as a public citizen. [Citations omitted.]Regarding the due process claim, the Court wrote:
The school board may regulate a teacher's speech in the classroom if it has provided the teacher with specific notice of what conduct is prohibited. LeVake's due process claim is premised on his belief that respondents deprived him of his liberty interest to teach his class free "from state action which impinges upon and violated his constitutional rights to free speech and free exercise" by failing to provide him with adequate notice of what types of expression were prohibited before reassigning him. The cases LeVake relies on in making this argument involve the termination of teachers, but LeVake was not terminated. In fact, he was not even demoted. Further, before accepting the position to teach tenth-grade biology, LeVake understood that respondents' prescribed curriculum included teaching students about evolution. LeVake was given sufficient notice about what he could and could not teach through the established curriculum and the syllabus. [Citations omitted.]Concluding the decision, the Court wrote:
Because LeVake's position paper and his statement to Hubert make it clear that LeVake would not teach the required course curriculum in the manner established by the school board, LeVake has not presented any genuine issue of material fact regarding his free exercise, free speech, and due process claims. Thus, the district court did not err in granting respondents' motion for summary judgment.For the complete text of the decision, see http://www.lawlibrary.state.mn.us/archive/ctappub/0105/c8001613.htm>.
Creationism and the Emergence of Animals: The Original Spin
In 1999 I attended a meeting near Chengjiang, China on "The Origins of Animal Body Plans and Their Fossil Records" (Chen and others 1999). The meeting was held near Chengjiang because there are fantastic fossils of Early Cambrian animals in the area. What makes these fossils remarkable is that they not only preserve only the hard, skeletonized parts of animals, but also contain replicas of the external form of their soft parts. Such sites of such "exceptional preservation" are rare, but are enormously important scientifically for the glimpses they give us of the panorama of early animal life (Gould 1989; Conway Morris 1998).
Although the meeting was billed as a scientific conference, a number of anti-evolutionists were also in attendance, including several people associated with the Center for the Renewal of Science and Culture (CRSC), the creationist arm of the Discovery Institute, a Seattle-based organization that advocates "intelligent design" as an explanation for biotic diversity. Indeed, one of the principal organizers of the meeting was Paul Chien, a marine toxicologist at the University of San Francisco in Santa Rosa, California, and a senior fellow of the CRSC. The talks were scheduled to provide prominent slots for CRSC fellows and their associates. Even more troubling was the fact that scientists were not informed of the involvement of the CRSC before arriving at Chengjiang and only became aware of its involvement once they inspected the printed abstracts of the presentations. Many scientists are becoming concerned about the activities of the CRSC, and so it seems important to clarify what occurred at this conference.
My experience at the meeting convinces me that all the anti-evolutionists who attended were motivated by political, not scientific, interests. There is nothing inherently wrong with that, of course, although it is markedly unusual in a scientific conference. I even had to admire the nerve of several anti-evolutionist speakers who made presentations in front of opponents as formidable as Eric Davidson, the developmental biologist from the California Institute of Technology and a member of the US National Academy of Sciences. Nevertheless, I could find nothing in any of their presentations that provided scientific evidence suggestive of the action of an intelligent designer, undiscovered natural laws that govern the development of form, or the action of some unspecified principle of "harmony" that drove the early evolution of animals.
What was presented were old Paleyian arguments for design cast up in a variety of molecular guises. These arguments are based on the notion that, because we do not currently understand all aspects of the evolution of life, evolutionary ideas must therefore be fundamentally flawed and, therefore, there must be an intelligent designer. Rather than presenting a coherent argument for the action of an intelligent designer, these advocates were more interested in exploring what they present as weaknesses in evolutionary thinking. Their position ignores the colossal amount of concordant evidence supporting evolution and refuses to acknowledge the legitimate complexity of modern evolutionary thinking.
Unlike the contingent of scientists, the anti-evolutionists at the meeting all appeared to have known of the CRSC's involvement with the meeting before their arrival. These anti-evolutionists represented a broad range of anti-evolutionary viewpoints. At one extreme their camp included Michael Denton, a senior fellow of the CRSC, whose professed "pagan" personal philosophy, as he explained it to me, seemed about as far from biblical literalism as one could imagine. At the other extreme there was a young, fervently Christian student who spoke candidly of his belief in young-earth creationism. Denton is a qualified geneticist, and I could trace no scientific or philosophical link between his platonic notions of natural laws that govern the form of animal archetypes and the strict biblical-literalist, young-earth stance espoused by the student. The fact that both these individuals claimed that the Discovery Institute had financially supported their attendance at the meeting suggests that the Institute's involvement in the meeting was not motivated primarily by the desire to present a coherent scientific argument for "intelligent design". Rather, it suggests that the Discovery Institute was more interested in supporting any views that appear to challenge evolutionary explanations, regardless of whether these views are mutually exclusive.
Although I cannot read the minds of the individuals associated with the CRSC, I can advance a reasoned interpretation of what might be motivating their interest in this issue. The US Supreme Court ruled in Edwards v Aguillard (1987) that creationism cannot be taught in science classes in public schools because it is not a scientific concept and because there is no secular purpose in teaching it. Advocates of intelligent design creationism (IDC) may attempt to circumvent this ruling by arguing that "intelligent design" is a scientific alternative to evolution. Tactics for doing so might include having IDC representatives speak at scientific meetings alongside recognized scientists and having their ideas published alongside scientific papers in conference proceedings. The association of "intelligent design" with legitimate scientific conferences and publications could be presented to US lawmakers as evidence that advocates of IDC are pursuing reputable science rather than sectarian politics, and that the scientific community accepts "intelligent design" as a viable and productive topic of study. This in turn would support the recent debate about "alternatives to evolution" to public school science classes. The remainder of this article seeks to identify specific positions that those associated with the Discovery Institute appear to take with regard to scientific evidence on this matter, and then respond to these positions from my own viewpoint as a scientist.
IDC advocates claim that: 1) The major groups of animals had separate, independent origins (by "major groups of animals" anti-evolutionists mean the marine creatures without backbones that commonly correspond to the "invertebrate phyla" such as Mollusca, Brachiopoda, Arthropoda, and so on ... in addition to the first Chordates). This position, of course, denies common ancestry among living taxa. 2) These major animal groups originated over a "very short" interval of geological time associated with the "Cambrian explosion" (some IDCs suggest a period of 2-3 million years). This is much shorter, of course, than expected by most evolutionary models.
These two points lead to the conclusion that the rate and magnitude of innovation were far too high to be accounted for by natural selection and can only be explained as the actions of a designer.
The IDC position is challenged by the scientific facts. The claim that the major groups of animals appear suddenly in the fossil record is easily demonstrated as incorrect by the extensive fossil record of early animal evolution that stretches back several tens of millions of years earlier than the Chengjiang fossil beds. So anti-evolutionists are in deep denial of the fossil record when they cite the impossibly short interval during which new taxa emerged.
The claim that the major animal groups originated separately and independently is equally weak. The origin of animals took place relatively late in the earth's 4.6-billion-year history; however, recent fossil discoveries contain evidence of a long and rich ancestry for animal phyla. Of course, when most people think of the "major groups" of animals, they envision the vertebrate classes that represent what first think of as "animals" today — mammals, reptiles, amphibians, fishes, and birds. Vertebrates represent only some of members of one phylum — the Chordata. There are numerous other phyla, represented by such disparate creatures as starfish (Phylum Echinodermata), spiders and crabs (Phylum Arthropoda), clams and snails (Phylum Mollusca), in addition to many others.
In a broad sense each different phylum has a distinctly different fundamental structure and development — and each represents a different "body plan", or set of "body plans". Scientists understand body plans to refer to the major features of adult bodies in metazoans and/or of the developmental trajectory that gives rise to the adult body. Different body plans are distinguished on the basis of variation in features such as aspects of skeletal construction, symmetry, internal body cavities, segmentation patterns, and appendage structure.
Almost all metazoan phyla can be instantly distinguished from one another on the basis of variation in these fundamental features. The animal taxa that emerged out of the Precambrian are clearly related to living taxa, but even the early chordates — the founding members of the phylum that would later give rise to the vertebrates — bore little superficial resemblance to the vertebrates that would finally appear 100 million years later.
The IDC conclusion that the Cambrian Explosion can be explained only by reference to an intelligent designer is unsupported by the scientific evidence, as discussed below. Moreover, the common anti-evolutionist strategy of quoting Darwin as if science has stood still since he wrote On the Origin of Species backfires. One of the most remarkable aspects of the Origin is the way in which Darwin identified potential criticisms of his theory and addressed them with refreshing honesty. He was very frank about what he thought was the absence of fossils in rocks older than those bearing the oldest skeletonized fossils known in Europe (now known to be about 525 million years old), recognizing this absence as a "valid argument against the views here entertained" (Darwin 1859 [1964: 308]). After admitting that he had no solid explanation of the absence of these fossils, Darwin advanced some hypotheses about the incompleteness of the geological record. It is instructive to compare what we now know about the early history of life on the planet with what was known in Darwin's time and to ask how his views have stood the test of time.
First, we need to decide what it actually is to be an animal. To do so, we must identify unique characters that are shared by all animals and distinguish them from other types of organisms. These are the characters that diagnose animals as a natural group and are considered ancestral for all animals. Once we have done that, we can proceed to identify other novel characters that distinguish specific subgroups (or "clades") of animals from the ancestral state and from each other. This process of distinguishing groups within groups produces a hierarchical nested set of related animals.
Animals are multicellular organisms that have cells specialized to perform particular functions; these cells are held together by an organic glue called extracellular matrix (ECM). On the basis of these features, biologists have long inferred that all animals constitute a natural group and evolved from a single common ancestor. But multicellularity with specialized cells is a general similarity — one that applies to some organisms, such as trees, that we would all agree are not animals — so multicellularity with specialized cells is not enough to prove common ancestry of all animal taxa. These features may have evolved independently in different lineages of single-celled organisms, and so it is the highly specific shared features, such as the nature of ECM, that assume a special significance for defining what it means to be an animal. This is because very specific similarities are unlikely to have arisen convergently and so point towards a single common ancestor for all animals. Recent discoveries of numerous very specific properties shared by all animals provide extremely strong evidence for their common ancestry.
We now know that all animals share not only general similarities but also many highly specific genes, for example, the transcription factors of the ets gene family, paired-box genes, and a primordial Hox gene (Peterson and Davidson 2000). These genes are fundamental in organizing the layout of animal bodies, and have such similar molecular structures that we can confidently conclude that they result from common ancestry, rather than from later evolutionary convergence. Thus they provide extremely strong evidence that all animal groups arose from only one lineage of single-celled ancestors.
The simplest animals, sponges, have all the characters mentioned above (along with a few unique characters of their own), but they lack the next set of features that diagnose an evolutionarily clade of animals derived somewhat later. In accordance with the nested hierarchy of characters we expect, all animals, except the sponges, to exhibit embryonic gastrulation (a special infolding of the wall of the initial ball of cells formed after fertilization), and the duplication of the primordial Hox gene. These features form the basis for diagnosing a more derived group of animals that includes corals and all other metazoans (ourselves included), but excludes the more basal clade that contains the sponges. At each step of the evolution of animals, we can demonstrate a similar diagnostic branching.
What we have just done is to use the distribution of novel features to map the evolutionary changes that both diagnose what makes an animal in the first place and tell us how animals within the group are related. The resultant hierarchical nested sets of related animals are exactly what we would expect according to an evolutionary model. By any reasonable evaluation, these must be considered strong evidence of the evolutionary relatedness of all animals. Of course, the spate of new information on molecular structures and developmental genetics raises many new questions, but the big picture is that these new data can only be viewed as furnishing wonderful vindication of Darwin's central notions. Time and time again, we find that animal subgroups thought to be related on the basis of morphological evidence also share exclusive similarities in gene sequences and in patterns of developmental control, as predicted by evolutionary theory. At the Chengjiang meeting, the CRSC's Jonathan Wells suggested that developmental genetic evidence favors separate origins from different single-celled lineages for the major animal groups. But his suggestion contradicts a wealth of scientific evidence and therefore must, in my view, arise from non-scientific convictions.
Our understanding of the major relationships among animal groups is now stabilizing. This is not to say that we currently know all there is to know about animals' relationships or molecular biology — far from it, which is why evolutionary biology is an exciting area of research. Anyone with knowledge of developmental biology and sufficient time can find aspects of specific systems or pathways the operation and evolution of which are not now fully understood. But what we do understand strengthens the case for evolution because new insights and methods of analysis, unthinkable in Darwin's day, yet again fulfill the predictions of the evolutionary model.
What are the implications of the pattern of relatedness discussed above for evolution and for intelligent design creationism? First and most important, it clearly falsifies the IDC claim that animal groups appeared separately and independently. Instead, we see a hierarchy of the distribution of shared features — some general to the group as a whole, others specific to particular subgroups. Such a distribution of features is predicted by evolutionary theory, which was proposed long before most of these features had been recognized. It is not concordant with the idea of multiple independent origins of animals, because that model would have no compelling basis on which to predict a hierarchical arrangement of such shared features.
An apologist for "intelligent design" could argue that a designer worked sequentially in a series of small steps, which could explain why the features defining clades are arranged hierarchically. Curiously, however, members of the CRSC apparently do not apply this explanation to the Cambrian biota. Rather, they persist in asserting the independent origins of different animal groups, despite overwhelming scientific evidence against that viewpoint.
The earliest fossils currently known occur in rocks from western Australia that date from around 3465 million years ago (Shopf 1993), and a reasonably good fossil record is known from that time onwards. The earliest chemical evidence of life itself is even older, about 3900 million years ago (Mojzsis and Harrison 2000). The earliest fossils are prokaryotic cyanobacteria, and as we move up through the geological column toward the base of the Cambrian these forms are joined by more complex fossils, such as those of eukaryotic cells, by about 1800 million years ago (Knoll 1992). (It is important to reiterate that the first occurrence of a fossil marks the minimum age for the appearance of the group to which it belongs, but the origin of the group often is far earlier, as Darwin suggested. For example, there is good chemical evidence that eukaryotes existed from about 2700 million years ago [Brocks and others 1999], but the earliest fossils yet found that are widely accepted as eukaryotes are some 900 million years younger.) The increase in complexity and diversity of fossils through the Precambrian up toward the boundary with the Cambrian is concordant with an evolutionary explanation, and the sequence of appearance makes sense in evolutionary terms. Darwin would be justified in feeling vindicated by these discoveries of definitive Precambrian fossils, which were unknown at the time he was writing. Anyone who suggests that Darwin's 19th-century difficulty with an apparently abrupt start to the fossil record still pertains today simply has not considered the evidence.
Although the methods used in these estimates are not currently as precise as they may yet become, it is hardly a surprise that the dates for the divergence of major groups are spread over a wide timespan. This is because major groups of animals are related in a hierarchical fashion, as we saw above, and would thus be expected to diverge from an ancestral lineage at different times. Therefore, we would expect the split between vertebrates and echinoderms, groups that share a wide range of derived features, to have occurred more recently than, say, the split between sponges and the common ancestors of echinoderms and vertebrates. Why? Because sponges are among the most basic animals with the fewest derived features, and so we would expect them to have split off earlier. And this is exactly what we do find — sponges and other animals are estimated to have separated about 950 million years ago, whereas echinoderms and vertebrates split from each other somewhere between 700 to 550 million years ago (Smith 1999).
Three lines of evidence provide important constraints on estimates of when the key events in animal evolution happened. Although the three lines of evidence are independent of one another, the results of each approach are concordant with the inescapable conclusions that the origin of animal groups was a protracted affair that required at least 100 million years and possibly far longer, and that the origin of animal groups took place in the Precambrian, long before the "Cambrian Explosion". Thus the IDC position that the origin of animals occurred very quickly as part of the Cambrian Explosion is falsified by these lines of evidence.
The three lines of evidence are:
1. Molecular clocks. If we can estimate the rate at which particular organic molecules change among living groups whose divergence times are well known, then we can compare the amount of difference in the same molecules among a wide variety of animals to calculate approximately when these forms diverged. The estimated rate of change in these molecules is the basis for molecular clocks, and the relationships suggested by multiple molecular clocks demonstrate concordant patterns. We now know that the major novel characters that distinguish the major groups of animals appeared at most 1500 million years ago, but at the latest no more than about 560 million years ago — 15 million years before the start of the Cambrian Period (Lynch 1999; Smith 1999), and about 40 million years before the age of the fossils of Chengjiang.
2. Evidence from body fossils. There is a substantial Precambrian fossil record of animal bodies and body parts. For example the calcareous tube Cloudina represents the outer skeleton of an animal, and has long been known from Precambrian rocks at least 550 million years old. There is undisputed evidence of fossil sponges dated about 545 million years ago (Brasier and others 1997), right about at the Cambrian boundary (544 million years ago), but there are also fossils of sponge embryos dated at around 580 million years ago (Chen and others 2000). Some scientists have also argued that some members of the Ediacaran fauna — an enigmatic suite of late Precambrian body fossils about 555 million years old — represent a variety of animal groups with representatives living today. There is widespread agreement that at least some of these forms represent sponges or cnidarians (jellyfishes, corals, sea anemones, and hydras), but some scientists argue that arthropods and mollusks are also present in the Ediacaran assemblages. Moreover, Chen and others (2000) recently claimed to have recovered embryos similar to those of derived groups such as arthropods and echinoderms in deposits about 580 million years old. These researchers argue that early animal evolution took place at small, almost microscopic sizes, unlikely to leave much of a fossil record. If these interpretations of the Precambrian fossil record are correct, they strengthen the case for argument that the differentiation of the "major groups" occurred much earlier than their dramatic appearance in the Cambrian Period.
3. Evidence from trace fossils. Trace fossils are evidence of the activity of animals, such as the burrows, tracks and trails that animals left on the sediment surface or beneath it in the seafloor. There is no serious argument that large trace fossils were formed by anything other than animals, although there is some debate as to which are the earliest trace fossils, because many simple trace fossils, such as might be formed by the earliest animals, are easily confused with other structures produced by inorganic processes. One thing is very clear: there are many trace fossils in Precambrian rocks at least 555 million years ago, and possibly far earlier (Budd and Jensen 2000). It is also clear that the order of appearance of trace fossils proceeds sequentially from simple to more complex forms (Budd and Jensen 2000). Indeed, one feature that identifies the Cambrian period in the geological is the appearance of the burrow network Treptichnus pedum. The distinctive form of this trace leaves no doubt that it was formed by an animal with a central gut and a reasonably sophisticated neural system. T pedum first appears some 10 million years before skeletonized fossils become common and about 20 million years before the Chengjiang fauna lived (about 525 million years ago).
What does all this mean? The lineages that include the major groups of animals (each major group being characterized by a particular "body plan") certainly diverged during the late Precambrian and not during the Cambrian itself. Because major animal groups share so many developmental features, these features must have originated before these lineages split — that is, at least 580 million years ago, some 45 million years before the beginning of the Cambrian Period. Fossil evidence, both from trace and body fossils, is consistent with this interpretation, and the trace-fossil record suggests the stepwise acquisition of increasingly complex behaviors from about 555 million years ago onward. Hence, any suggestion that the appearance of the first representatives of "modern" animal groups in the Cambrian correlates specifically with the time of origin of these groups (an argument favored by proponents of IDC) is clearly refuted by the evidence, which shows that the major groups of animals originated during the Precambrian.
It is also important to appreciate that about 20 million years pass from the beginning of the Cambrian to the time of the Chengjiang fauna — the Burgess Shale fauna (discussed in Gould's Wonderful Life [1989]) is even more recent. Because Treptichnus pedum, the marker for the start of the Cambrian, was made by an animal with a gut and complex behavior, it is certain that large animals with 3 layers of cells (the triploblasts) were living long before the debut of the stars of Wonderful Life. Any suggestion that animals evolved within "a mere 2 or 3 million years" (Heeren 2000) of the Chengjiang fauna is an irresponsible and bizarre misrepresentation that flatly contradicts scientific facts.
New discoveries and interpretations in paleontology and developmental genetics have changed the scientific landscape significantly since Gould wrote Wonderful Life. Wills and others (1994) have suggested that Gould may have overestimated the diversity of Cambrian animals, although scientists disagree on how best to measure this diversity. Nevertheless, Gould's central point — that at least some groups of Cambrian animals exhibit a morphological diversity that is at least comparable to that seen in living fauna — remains valid and should not be underestimated. Compared with the fauna of the later Precambrian, the Cambrian fauna is strikingly diverse; the recent discoveries of early vertebrate-like fossils in the Chengjiang beds simply emphasize the point that much innovation was in place by relatively early in the Cambrian Period.
The aspect of Gould's views that has been most strongly challenged is the idea that several fundamentally distinct animal body plans have vanished since the Middle Cambrian. The definition of what constitutes a "fundamentally distinct animal body plan" is difficult because it requires an evaluation of the evolutionary "weight" or significance of particular features; we are not yet sure how to assess this weight objectively. But what has become clear recently is that the Burgess Shale and Chengjiang faunas contain not only members of "crown" groups (those with living representatives), but also animals in "stem" groups, which are more distant relatives of these surviving groups (Budd and Jensen 2000).
Because species belonging to stem groups are typically extinct, their place in the phylogenetic tree can be difficult to interpret. It turns out that many of the forms Gould interpreted as representing additional fundamentally distinct body plans may merely be evolutionary adventures or "experiments" within the lineages of the major groups of animals we know today. So, the unusual fauna of Chengjiang and in the Burgess Shale likely represent way stations along the road to the establishment of the modern groups rather than cul-de-sacs of evolutionary innovation. Some forms we can easily recognize as linked to living groups; others are more enigmatic (and stem groups, of course, show evidence of transitional states). But such difficulty in interpreting early fossils, of course, is what Darwin predicted in the Origin of Species, because he knew that the selective action of extinction throughout geological time could only tend to emphasize differences, not similarities, among these major lineages of animals.
The bottom line is that the establishment of modern animal groups was a protracted affair that began no later than about 600 million years ago, extended across the Precambrian-Cambrian boundary, was still in progress during the Early Cambrian Epoch, and continued after the close of the Cambrian Period. Accordingly, science currently tells us that there was, at a minimum, about 100 million years from the time when the first sponge-like animals originated until the origin of representatives of all the major living lineages or body plans.
Because animals did not evolve in a geological instant, there is no need to invoke some novel evolutionary — or supernatural — process to explain their appearance. This is not to say that the appearance of every novel feature is of the same importance for later evolution or that the rate of appearance of novel features was constant throughout the entire interval. Scientists do not demand such restrictions, even though anti-evolutionists frequently present them as basic premises of evolutionary explanations.
It is clear that there was a fundamental transition that took place over an extended interval across the Precambrian-Cambrian boundary. That transition reflects a dramatic shift in the structure of the ecosystems of early animals, which must have been at least partly fueled by the appearance of new biological innovations. Although a rich mixture of modern groups and their early relatives may have persisted throughout the Cambrian, there is a clear contrast between these generally familiar forms and the more enigmatic fossils from the Precambrian, such as those from Ediacara in Australia. It is clear that the transition into the Cambrian marks a pivotal time in life history. But although much tinkering went on in the Cambrian and thereafter, the most fundamental steps in the origins of animal groups took place during the Precambrian.
To return to Darwin, how does our current knowledge affect his "difficulty" with the "Sudden appearance of groups .... in the lowest known fossiliferous strata"? The answer is clear: Darwin's difficulty has evaporated. We have now identified thousands of fossils that appear earlier in the fossil record than the point at which Darwin thought it suddenly began. Darwin suspected that the impression of sudden appearance was false, and speculated that the false impression was due to the poor preservation of the older rocks in Europe and inadequate attention given to the fossil record. He has now been vindicated. The sequence of appearances that we now know is consistent with evolution, and the additional support for the common descent of animal phyla from new lines of inquiry that even Darwin could not have imagined only reinforces the brilliant predictive power of his insight. Today scientists might quibble about whether he assumed constant of rates of evolution with regard to the origin of animals. But despite this disagreement over rates of change, these fossils show that Darwin was right to suggest that life had been around for far longer before the beginning of the Cambrian than it has been since. As a result, it is appropriate to think of the Cambrian as a period of great phylogenetic diversification — what scientists call an evolutionary "radiation."
It is perhaps inevitable that those motivated by a nonscientific agenda will seek to extract snippets and sound bites from the scientific arguments, package them out of context, and feed them to the general public. This is what Fred Heeren did. Heeren is an anti-evolutionist writer who attended the Chengjiang meeting and then peddled his distorted version of the Cambrian radiation to the popular media, with obvious success (see Heeren 2000, an article in the Boston Globe).
Even if creationist misrepresentation of science is inevitable, it is nevertheless regrettable. Deep time was discovered 200 years ago and is now old news. Almost immediately, scientists recognized the sequential appearance of organisms in the geologic record, demonstrating the development of life's diversity through time, and this has never been seriously questioned in scientific circles. The world will be a better place when its human residents, in the brief flashes of time that each of us is privileged to experience, celebrate what science tells us about our place in nature.
Although the meeting was billed as a scientific conference, a number of anti-evolutionists were also in attendance, including several people associated with the Center for the Renewal of Science and Culture (CRSC), the creationist arm of the Discovery Institute, a Seattle-based organization that advocates "intelligent design" as an explanation for biotic diversity. Indeed, one of the principal organizers of the meeting was Paul Chien, a marine toxicologist at the University of San Francisco in Santa Rosa, California, and a senior fellow of the CRSC. The talks were scheduled to provide prominent slots for CRSC fellows and their associates. Even more troubling was the fact that scientists were not informed of the involvement of the CRSC before arriving at Chengjiang and only became aware of its involvement once they inspected the printed abstracts of the presentations. Many scientists are becoming concerned about the activities of the CRSC, and so it seems important to clarify what occurred at this conference.
My experience at the meeting convinces me that all the anti-evolutionists who attended were motivated by political, not scientific, interests. There is nothing inherently wrong with that, of course, although it is markedly unusual in a scientific conference. I even had to admire the nerve of several anti-evolutionist speakers who made presentations in front of opponents as formidable as Eric Davidson, the developmental biologist from the California Institute of Technology and a member of the US National Academy of Sciences. Nevertheless, I could find nothing in any of their presentations that provided scientific evidence suggestive of the action of an intelligent designer, undiscovered natural laws that govern the development of form, or the action of some unspecified principle of "harmony" that drove the early evolution of animals.
What was presented were old Paleyian arguments for design cast up in a variety of molecular guises. These arguments are based on the notion that, because we do not currently understand all aspects of the evolution of life, evolutionary ideas must therefore be fundamentally flawed and, therefore, there must be an intelligent designer. Rather than presenting a coherent argument for the action of an intelligent designer, these advocates were more interested in exploring what they present as weaknesses in evolutionary thinking. Their position ignores the colossal amount of concordant evidence supporting evolution and refuses to acknowledge the legitimate complexity of modern evolutionary thinking.
Unlike the contingent of scientists, the anti-evolutionists at the meeting all appeared to have known of the CRSC's involvement with the meeting before their arrival. These anti-evolutionists represented a broad range of anti-evolutionary viewpoints. At one extreme their camp included Michael Denton, a senior fellow of the CRSC, whose professed "pagan" personal philosophy, as he explained it to me, seemed about as far from biblical literalism as one could imagine. At the other extreme there was a young, fervently Christian student who spoke candidly of his belief in young-earth creationism. Denton is a qualified geneticist, and I could trace no scientific or philosophical link between his platonic notions of natural laws that govern the form of animal archetypes and the strict biblical-literalist, young-earth stance espoused by the student. The fact that both these individuals claimed that the Discovery Institute had financially supported their attendance at the meeting suggests that the Institute's involvement in the meeting was not motivated primarily by the desire to present a coherent scientific argument for "intelligent design". Rather, it suggests that the Discovery Institute was more interested in supporting any views that appear to challenge evolutionary explanations, regardless of whether these views are mutually exclusive.
Although I cannot read the minds of the individuals associated with the CRSC, I can advance a reasoned interpretation of what might be motivating their interest in this issue. The US Supreme Court ruled in Edwards v Aguillard (1987) that creationism cannot be taught in science classes in public schools because it is not a scientific concept and because there is no secular purpose in teaching it. Advocates of intelligent design creationism (IDC) may attempt to circumvent this ruling by arguing that "intelligent design" is a scientific alternative to evolution. Tactics for doing so might include having IDC representatives speak at scientific meetings alongside recognized scientists and having their ideas published alongside scientific papers in conference proceedings. The association of "intelligent design" with legitimate scientific conferences and publications could be presented to US lawmakers as evidence that advocates of IDC are pursuing reputable science rather than sectarian politics, and that the scientific community accepts "intelligent design" as a viable and productive topic of study. This in turn would support the recent debate about "alternatives to evolution" to public school science classes. The remainder of this article seeks to identify specific positions that those associated with the Discovery Institute appear to take with regard to scientific evidence on this matter, and then respond to these positions from my own viewpoint as a scientist.
Why Anti-evolutionists Focus on the Origin of Animals and The "Cambrian Explosion"
It seems likely that the origin of animals will remain a favorite subject for anti-evolutionists over the coming years. Before reviewing the current scientific evidence concerning the origin of animals, I wish to outline the strategic position of IDC anti-evolutionists — especially those associated with the CRSC — with regard to the origin of animals as far as I understood it from the meeting.IDC advocates claim that: 1) The major groups of animals had separate, independent origins (by "major groups of animals" anti-evolutionists mean the marine creatures without backbones that commonly correspond to the "invertebrate phyla" such as Mollusca, Brachiopoda, Arthropoda, and so on ... in addition to the first Chordates). This position, of course, denies common ancestry among living taxa. 2) These major animal groups originated over a "very short" interval of geological time associated with the "Cambrian explosion" (some IDCs suggest a period of 2-3 million years). This is much shorter, of course, than expected by most evolutionary models.
These two points lead to the conclusion that the rate and magnitude of innovation were far too high to be accounted for by natural selection and can only be explained as the actions of a designer.
The IDC position is challenged by the scientific facts. The claim that the major groups of animals appear suddenly in the fossil record is easily demonstrated as incorrect by the extensive fossil record of early animal evolution that stretches back several tens of millions of years earlier than the Chengjiang fossil beds. So anti-evolutionists are in deep denial of the fossil record when they cite the impossibly short interval during which new taxa emerged.
The claim that the major animal groups originated separately and independently is equally weak. The origin of animals took place relatively late in the earth's 4.6-billion-year history; however, recent fossil discoveries contain evidence of a long and rich ancestry for animal phyla. Of course, when most people think of the "major groups" of animals, they envision the vertebrate classes that represent what first think of as "animals" today — mammals, reptiles, amphibians, fishes, and birds. Vertebrates represent only some of members of one phylum — the Chordata. There are numerous other phyla, represented by such disparate creatures as starfish (Phylum Echinodermata), spiders and crabs (Phylum Arthropoda), clams and snails (Phylum Mollusca), in addition to many others.
In a broad sense each different phylum has a distinctly different fundamental structure and development — and each represents a different "body plan", or set of "body plans". Scientists understand body plans to refer to the major features of adult bodies in metazoans and/or of the developmental trajectory that gives rise to the adult body. Different body plans are distinguished on the basis of variation in features such as aspects of skeletal construction, symmetry, internal body cavities, segmentation patterns, and appendage structure.
Almost all metazoan phyla can be instantly distinguished from one another on the basis of variation in these fundamental features. The animal taxa that emerged out of the Precambrian are clearly related to living taxa, but even the early chordates — the founding members of the phylum that would later give rise to the vertebrates — bore little superficial resemblance to the vertebrates that would finally appear 100 million years later.
The IDC conclusion that the Cambrian Explosion can be explained only by reference to an intelligent designer is unsupported by the scientific evidence, as discussed below. Moreover, the common anti-evolutionist strategy of quoting Darwin as if science has stood still since he wrote On the Origin of Species backfires. One of the most remarkable aspects of the Origin is the way in which Darwin identified potential criticisms of his theory and addressed them with refreshing honesty. He was very frank about what he thought was the absence of fossils in rocks older than those bearing the oldest skeletonized fossils known in Europe (now known to be about 525 million years old), recognizing this absence as a "valid argument against the views here entertained" (Darwin 1859 [1964: 308]). After admitting that he had no solid explanation of the absence of these fossils, Darwin advanced some hypotheses about the incompleteness of the geological record. It is instructive to compare what we now know about the early history of life on the planet with what was known in Darwin's time and to ask how his views have stood the test of time.
The scientific issues relating to the origin of animals and the Cambrian Explosion
What defines an animal, and how are different animal groups related?
The time around the Precambrian-Cambrian transition is important because it provides us with the first fossilized record of metazoans — multicellular animals with features such as differentiated organs and tissues — about 544 million years ago. I emphasize that "appearance" is not the same thing as "origin". There are myriad reasons related to the preservation and recovery of fossils that can explain why the first recorded appearance of a particular group can occur substantially after its evolutionary origin. The origin of animals is a complex issue for which several independent lines of evidence need to be investigated.First, we need to decide what it actually is to be an animal. To do so, we must identify unique characters that are shared by all animals and distinguish them from other types of organisms. These are the characters that diagnose animals as a natural group and are considered ancestral for all animals. Once we have done that, we can proceed to identify other novel characters that distinguish specific subgroups (or "clades") of animals from the ancestral state and from each other. This process of distinguishing groups within groups produces a hierarchical nested set of related animals.
Animals are multicellular organisms that have cells specialized to perform particular functions; these cells are held together by an organic glue called extracellular matrix (ECM). On the basis of these features, biologists have long inferred that all animals constitute a natural group and evolved from a single common ancestor. But multicellularity with specialized cells is a general similarity — one that applies to some organisms, such as trees, that we would all agree are not animals — so multicellularity with specialized cells is not enough to prove common ancestry of all animal taxa. These features may have evolved independently in different lineages of single-celled organisms, and so it is the highly specific shared features, such as the nature of ECM, that assume a special significance for defining what it means to be an animal. This is because very specific similarities are unlikely to have arisen convergently and so point towards a single common ancestor for all animals. Recent discoveries of numerous very specific properties shared by all animals provide extremely strong evidence for their common ancestry.
We now know that all animals share not only general similarities but also many highly specific genes, for example, the transcription factors of the ets gene family, paired-box genes, and a primordial Hox gene (Peterson and Davidson 2000). These genes are fundamental in organizing the layout of animal bodies, and have such similar molecular structures that we can confidently conclude that they result from common ancestry, rather than from later evolutionary convergence. Thus they provide extremely strong evidence that all animal groups arose from only one lineage of single-celled ancestors.
The simplest animals, sponges, have all the characters mentioned above (along with a few unique characters of their own), but they lack the next set of features that diagnose an evolutionarily clade of animals derived somewhat later. In accordance with the nested hierarchy of characters we expect, all animals, except the sponges, to exhibit embryonic gastrulation (a special infolding of the wall of the initial ball of cells formed after fertilization), and the duplication of the primordial Hox gene. These features form the basis for diagnosing a more derived group of animals that includes corals and all other metazoans (ourselves included), but excludes the more basal clade that contains the sponges. At each step of the evolution of animals, we can demonstrate a similar diagnostic branching.
What we have just done is to use the distribution of novel features to map the evolutionary changes that both diagnose what makes an animal in the first place and tell us how animals within the group are related. The resultant hierarchical nested sets of related animals are exactly what we would expect according to an evolutionary model. By any reasonable evaluation, these must be considered strong evidence of the evolutionary relatedness of all animals. Of course, the spate of new information on molecular structures and developmental genetics raises many new questions, but the big picture is that these new data can only be viewed as furnishing wonderful vindication of Darwin's central notions. Time and time again, we find that animal subgroups thought to be related on the basis of morphological evidence also share exclusive similarities in gene sequences and in patterns of developmental control, as predicted by evolutionary theory. At the Chengjiang meeting, the CRSC's Jonathan Wells suggested that developmental genetic evidence favors separate origins from different single-celled lineages for the major animal groups. But his suggestion contradicts a wealth of scientific evidence and therefore must, in my view, arise from non-scientific convictions.
Our understanding of the major relationships among animal groups is now stabilizing. This is not to say that we currently know all there is to know about animals' relationships or molecular biology — far from it, which is why evolutionary biology is an exciting area of research. Anyone with knowledge of developmental biology and sufficient time can find aspects of specific systems or pathways the operation and evolution of which are not now fully understood. But what we do understand strengthens the case for evolution because new insights and methods of analysis, unthinkable in Darwin's day, yet again fulfill the predictions of the evolutionary model.
What are the implications of the pattern of relatedness discussed above for evolution and for intelligent design creationism? First and most important, it clearly falsifies the IDC claim that animal groups appeared separately and independently. Instead, we see a hierarchy of the distribution of shared features — some general to the group as a whole, others specific to particular subgroups. Such a distribution of features is predicted by evolutionary theory, which was proposed long before most of these features had been recognized. It is not concordant with the idea of multiple independent origins of animals, because that model would have no compelling basis on which to predict a hierarchical arrangement of such shared features.
An apologist for "intelligent design" could argue that a designer worked sequentially in a series of small steps, which could explain why the features defining clades are arranged hierarchically. Curiously, however, members of the CRSC apparently do not apply this explanation to the Cambrian biota. Rather, they persist in asserting the independent origins of different animal groups, despite overwhelming scientific evidence against that viewpoint.
The extensive Precambrian fossil record
The second pillar of the IDC position — that major groups of animals appeared too quickly for natural processes to account for them without invoking the intervention of an intelligent designer — is equally unsupported by the scientific evidence. However, to expose the weakness requires some background information about the Precambrian-Cambrian transition.The earliest fossils currently known occur in rocks from western Australia that date from around 3465 million years ago (Shopf 1993), and a reasonably good fossil record is known from that time onwards. The earliest chemical evidence of life itself is even older, about 3900 million years ago (Mojzsis and Harrison 2000). The earliest fossils are prokaryotic cyanobacteria, and as we move up through the geological column toward the base of the Cambrian these forms are joined by more complex fossils, such as those of eukaryotic cells, by about 1800 million years ago (Knoll 1992). (It is important to reiterate that the first occurrence of a fossil marks the minimum age for the appearance of the group to which it belongs, but the origin of the group often is far earlier, as Darwin suggested. For example, there is good chemical evidence that eukaryotes existed from about 2700 million years ago [Brocks and others 1999], but the earliest fossils yet found that are widely accepted as eukaryotes are some 900 million years younger.) The increase in complexity and diversity of fossils through the Precambrian up toward the boundary with the Cambrian is concordant with an evolutionary explanation, and the sequence of appearance makes sense in evolutionary terms. Darwin would be justified in feeling vindicated by these discoveries of definitive Precambrian fossils, which were unknown at the time he was writing. Anyone who suggests that Darwin's 19th-century difficulty with an apparently abrupt start to the fossil record still pertains today simply has not considered the evidence.
When and how quickly did animals first appear, and did all "major groups" appear at the same time?
We do not yet know exactly when the first animals originated because we do not yet know exactly when the definitive characters of animals — extracellular matrix, the primordial Hox gene, the ets gene family, and so on — originated. There is a wide range of estimated dates for the differentiation of the major groups of animals from one another. Some studies suggest that this occurred as much as 1100 million years ago; others suggest a date closer to 600 million years ago (see Valentine and others 1999).Although the methods used in these estimates are not currently as precise as they may yet become, it is hardly a surprise that the dates for the divergence of major groups are spread over a wide timespan. This is because major groups of animals are related in a hierarchical fashion, as we saw above, and would thus be expected to diverge from an ancestral lineage at different times. Therefore, we would expect the split between vertebrates and echinoderms, groups that share a wide range of derived features, to have occurred more recently than, say, the split between sponges and the common ancestors of echinoderms and vertebrates. Why? Because sponges are among the most basic animals with the fewest derived features, and so we would expect them to have split off earlier. And this is exactly what we do find — sponges and other animals are estimated to have separated about 950 million years ago, whereas echinoderms and vertebrates split from each other somewhere between 700 to 550 million years ago (Smith 1999).
Three lines of evidence provide important constraints on estimates of when the key events in animal evolution happened. Although the three lines of evidence are independent of one another, the results of each approach are concordant with the inescapable conclusions that the origin of animal groups was a protracted affair that required at least 100 million years and possibly far longer, and that the origin of animal groups took place in the Precambrian, long before the "Cambrian Explosion". Thus the IDC position that the origin of animals occurred very quickly as part of the Cambrian Explosion is falsified by these lines of evidence.
The three lines of evidence are:
1. Molecular clocks. If we can estimate the rate at which particular organic molecules change among living groups whose divergence times are well known, then we can compare the amount of difference in the same molecules among a wide variety of animals to calculate approximately when these forms diverged. The estimated rate of change in these molecules is the basis for molecular clocks, and the relationships suggested by multiple molecular clocks demonstrate concordant patterns. We now know that the major novel characters that distinguish the major groups of animals appeared at most 1500 million years ago, but at the latest no more than about 560 million years ago — 15 million years before the start of the Cambrian Period (Lynch 1999; Smith 1999), and about 40 million years before the age of the fossils of Chengjiang.
2. Evidence from body fossils. There is a substantial Precambrian fossil record of animal bodies and body parts. For example the calcareous tube Cloudina represents the outer skeleton of an animal, and has long been known from Precambrian rocks at least 550 million years old. There is undisputed evidence of fossil sponges dated about 545 million years ago (Brasier and others 1997), right about at the Cambrian boundary (544 million years ago), but there are also fossils of sponge embryos dated at around 580 million years ago (Chen and others 2000). Some scientists have also argued that some members of the Ediacaran fauna — an enigmatic suite of late Precambrian body fossils about 555 million years old — represent a variety of animal groups with representatives living today. There is widespread agreement that at least some of these forms represent sponges or cnidarians (jellyfishes, corals, sea anemones, and hydras), but some scientists argue that arthropods and mollusks are also present in the Ediacaran assemblages. Moreover, Chen and others (2000) recently claimed to have recovered embryos similar to those of derived groups such as arthropods and echinoderms in deposits about 580 million years old. These researchers argue that early animal evolution took place at small, almost microscopic sizes, unlikely to leave much of a fossil record. If these interpretations of the Precambrian fossil record are correct, they strengthen the case for argument that the differentiation of the "major groups" occurred much earlier than their dramatic appearance in the Cambrian Period.
3. Evidence from trace fossils. Trace fossils are evidence of the activity of animals, such as the burrows, tracks and trails that animals left on the sediment surface or beneath it in the seafloor. There is no serious argument that large trace fossils were formed by anything other than animals, although there is some debate as to which are the earliest trace fossils, because many simple trace fossils, such as might be formed by the earliest animals, are easily confused with other structures produced by inorganic processes. One thing is very clear: there are many trace fossils in Precambrian rocks at least 555 million years ago, and possibly far earlier (Budd and Jensen 2000). It is also clear that the order of appearance of trace fossils proceeds sequentially from simple to more complex forms (Budd and Jensen 2000). Indeed, one feature that identifies the Cambrian period in the geological is the appearance of the burrow network Treptichnus pedum. The distinctive form of this trace leaves no doubt that it was formed by an animal with a central gut and a reasonably sophisticated neural system. T pedum first appears some 10 million years before skeletonized fossils become common and about 20 million years before the Chengjiang fauna lived (about 525 million years ago).
What does all this mean? The lineages that include the major groups of animals (each major group being characterized by a particular "body plan") certainly diverged during the late Precambrian and not during the Cambrian itself. Because major animal groups share so many developmental features, these features must have originated before these lineages split — that is, at least 580 million years ago, some 45 million years before the beginning of the Cambrian Period. Fossil evidence, both from trace and body fossils, is consistent with this interpretation, and the trace-fossil record suggests the stepwise acquisition of increasingly complex behaviors from about 555 million years ago onward. Hence, any suggestion that the appearance of the first representatives of "modern" animal groups in the Cambrian correlates specifically with the time of origin of these groups (an argument favored by proponents of IDC) is clearly refuted by the evidence, which shows that the major groups of animals originated during the Precambrian.
It is also important to appreciate that about 20 million years pass from the beginning of the Cambrian to the time of the Chengjiang fauna — the Burgess Shale fauna (discussed in Gould's Wonderful Life [1989]) is even more recent. Because Treptichnus pedum, the marker for the start of the Cambrian, was made by an animal with a gut and complex behavior, it is certain that large animals with 3 layers of cells (the triploblasts) were living long before the debut of the stars of Wonderful Life. Any suggestion that animals evolved within "a mere 2 or 3 million years" (Heeren 2000) of the Chengjiang fauna is an irresponsible and bizarre misrepresentation that flatly contradicts scientific facts.
What, then, does the Cambrian Explosion represent?
The Chengjiang fauna, like that of the Burgess Shale and several other Cambrian sites, is truly remarkable for the quality and the range of biological diversity that it preserves. Detailed work on these faunas has revealed a remarkable fact — that animals related to the major living groups of animals were present from at least the later portion of Early Cambrian Epoch. In Wonderful Life Gould (1989) made much of this important fact by suggesting that because forms comparable to major groups of living animals were already present in the Cambrian, later evolutionary history has mostly involved variation on established themes, rather than the origin of really major new animal body plans. He also stressed that several fundamentally distinct animal body plans present in the Cambrian have since vanished. These body plans are found both in lineages that belong to existing phyla (for example, some extinct groups of Arthropoda) and in lineages that seem allied to other metazoans but are obviously not members of living groups (for example, the Archaeocyatha). Thus, according to Gould, most of the fundamental innovations in body plan were in place by Middle Cambrian time, and the Cambrian fauna was more diverse than its modern counterpart.New discoveries and interpretations in paleontology and developmental genetics have changed the scientific landscape significantly since Gould wrote Wonderful Life. Wills and others (1994) have suggested that Gould may have overestimated the diversity of Cambrian animals, although scientists disagree on how best to measure this diversity. Nevertheless, Gould's central point — that at least some groups of Cambrian animals exhibit a morphological diversity that is at least comparable to that seen in living fauna — remains valid and should not be underestimated. Compared with the fauna of the later Precambrian, the Cambrian fauna is strikingly diverse; the recent discoveries of early vertebrate-like fossils in the Chengjiang beds simply emphasize the point that much innovation was in place by relatively early in the Cambrian Period.
The aspect of Gould's views that has been most strongly challenged is the idea that several fundamentally distinct animal body plans have vanished since the Middle Cambrian. The definition of what constitutes a "fundamentally distinct animal body plan" is difficult because it requires an evaluation of the evolutionary "weight" or significance of particular features; we are not yet sure how to assess this weight objectively. But what has become clear recently is that the Burgess Shale and Chengjiang faunas contain not only members of "crown" groups (those with living representatives), but also animals in "stem" groups, which are more distant relatives of these surviving groups (Budd and Jensen 2000).
Because species belonging to stem groups are typically extinct, their place in the phylogenetic tree can be difficult to interpret. It turns out that many of the forms Gould interpreted as representing additional fundamentally distinct body plans may merely be evolutionary adventures or "experiments" within the lineages of the major groups of animals we know today. So, the unusual fauna of Chengjiang and in the Burgess Shale likely represent way stations along the road to the establishment of the modern groups rather than cul-de-sacs of evolutionary innovation. Some forms we can easily recognize as linked to living groups; others are more enigmatic (and stem groups, of course, show evidence of transitional states). But such difficulty in interpreting early fossils, of course, is what Darwin predicted in the Origin of Species, because he knew that the selective action of extinction throughout geological time could only tend to emphasize differences, not similarities, among these major lineages of animals.
The bottom line is that the establishment of modern animal groups was a protracted affair that began no later than about 600 million years ago, extended across the Precambrian-Cambrian boundary, was still in progress during the Early Cambrian Epoch, and continued after the close of the Cambrian Period. Accordingly, science currently tells us that there was, at a minimum, about 100 million years from the time when the first sponge-like animals originated until the origin of representatives of all the major living lineages or body plans.
Because animals did not evolve in a geological instant, there is no need to invoke some novel evolutionary — or supernatural — process to explain their appearance. This is not to say that the appearance of every novel feature is of the same importance for later evolution or that the rate of appearance of novel features was constant throughout the entire interval. Scientists do not demand such restrictions, even though anti-evolutionists frequently present them as basic premises of evolutionary explanations.
It is clear that there was a fundamental transition that took place over an extended interval across the Precambrian-Cambrian boundary. That transition reflects a dramatic shift in the structure of the ecosystems of early animals, which must have been at least partly fueled by the appearance of new biological innovations. Although a rich mixture of modern groups and their early relatives may have persisted throughout the Cambrian, there is a clear contrast between these generally familiar forms and the more enigmatic fossils from the Precambrian, such as those from Ediacara in Australia. It is clear that the transition into the Cambrian marks a pivotal time in life history. But although much tinkering went on in the Cambrian and thereafter, the most fundamental steps in the origins of animal groups took place during the Precambrian.
To return to Darwin, how does our current knowledge affect his "difficulty" with the "Sudden appearance of groups .... in the lowest known fossiliferous strata"? The answer is clear: Darwin's difficulty has evaporated. We have now identified thousands of fossils that appear earlier in the fossil record than the point at which Darwin thought it suddenly began. Darwin suspected that the impression of sudden appearance was false, and speculated that the false impression was due to the poor preservation of the older rocks in Europe and inadequate attention given to the fossil record. He has now been vindicated. The sequence of appearances that we now know is consistent with evolution, and the additional support for the common descent of animal phyla from new lines of inquiry that even Darwin could not have imagined only reinforces the brilliant predictive power of his insight. Today scientists might quibble about whether he assumed constant of rates of evolution with regard to the origin of animals. But despite this disagreement over rates of change, these fossils show that Darwin was right to suggest that life had been around for far longer before the beginning of the Cambrian than it has been since. As a result, it is appropriate to think of the Cambrian as a period of great phylogenetic diversification — what scientists call an evolutionary "radiation."
The Precambrian/Cambrian radiation and creationism: the original spin
Animals are incredibly complex and wonderful, and understanding their early evolution requires a full consideration of many different lines of evidence. Much is known, new data are appearing at an unprecedented rate, and yet many questions still excite our scientific curiosity. Scientists such as Stephen Jay Gould and Simon Conway Morris are valiantly striving to make these exotic animals and abstruse issues accessible to the public. It is a privilege to be able to witness all this excitement.It is perhaps inevitable that those motivated by a nonscientific agenda will seek to extract snippets and sound bites from the scientific arguments, package them out of context, and feed them to the general public. This is what Fred Heeren did. Heeren is an anti-evolutionist writer who attended the Chengjiang meeting and then peddled his distorted version of the Cambrian radiation to the popular media, with obvious success (see Heeren 2000, an article in the Boston Globe).
Even if creationist misrepresentation of science is inevitable, it is nevertheless regrettable. Deep time was discovered 200 years ago and is now old news. Almost immediately, scientists recognized the sequential appearance of organisms in the geologic record, demonstrating the development of life's diversity through time, and this has never been seriously questioned in scientific circles. The world will be a better place when its human residents, in the brief flashes of time that each of us is privileged to experience, celebrate what science tells us about our place in nature.
References
Brasier MD, Green OR, Shields G. Ediacaran sponge spicule clusters from SW Mongolia and the origins of the Cambrian fauna. Geology 1997; 25: 303-6.Brocks JJ, Logan GA, Buick R, Summons RE. Archean molecular fossils and the early rise of eukaryotes. Science 1999; 285: 1033-6.
Budd GE, Jensen S. A critical reappraisal of the fossil record of the bilaterian phyla. Biological Reviews 2000; 75: 253-95.
Chen J-Y, Chien PK, Bottjer, DJ, Li G-X, Feng G. International symposium on the origins of animal body plans and their fossil records [abstract volume]. Early Life Research Center, Kunming, 1999
Chen J-Y, Oliveri P, Li C-W, Zhou G-Q, Gao F, Hagadorn JW, Peterson KJ, Davidson EH. Precambrian animal diversity: putative phosphatized embryos from the Doushantuo Formation of China. Proceedings of the National Academy of Science 2000; 97: 4457-62.
Conway Morris S. Crucible of Creation. Oxford: Oxford University Press, 1998.
Darwin C. On the Origin of Species. [Facsimile of the first edition of 1859.] Cambridge (MA): Harvard University Press, 1964.
Gould SJ. Wonderful Life. London: Hutchinson Radius, 1989.
Heeren F. A little fish challenges a giant of science. Boston Globe, May 30, 2000. E1, E4.
Knoll AH. The early evolution of eukaryotes: a geological perspective. Science 1992; 256: 622-7.
Lynch M. The age and relationships of the major animal phyla. Evolution 1999; 53: 319-25.
Mojzsis SJ, Harrison TM. Vestiges of a beginning; clues to the emergent biosphere recorded in the oldest known sedimentary rocks. GSA Today 2000; 10: 1-6.
Peterson KJ, Davidson EH. Regulatory evolution and the origin of the bilaterians. Proceedings of the National Academy of Sciences 2000; 97: 4430-3.
Schopf JW. Microfossils of the early Archean Apex Chert: new evidence for the antiquity of life. Science 1993; 260: 640-6.
Smith AB. Dating the origin of metazoan body plans. Evolution and Development 1999; 1: 138-42.
Valentine JW, Jablonski D, Erwin DH. Fossils, molecules and embryos: new perspectives on the Cambrian explosion. Development 1999; 126: 851-9.
Wills MA, Briggs DEG, Fortey RA. Disparity as an evolutionary index: a comparison of Cambrian and Recent arthropods. Paleobiology 1994; 20: 93-130.
Dinosaurs and Birds — an Update
In a short paper in Nature, John Ostrom (1973) first laid out a case for the descent of birds from theropod dinosaurs. At the time, other ideas had recently been proposed, linking birds to crocodiles or to a more vaguely defined group of archosaurs (the group that includes birds, dinosaurs, crocodiles, pterosaurs, and many extinct relatives). Although all three hypotheses had early proponents, only the dinosaur-bird hypothesis survived the decade, mainly because (1) the evidence was convincing, (2) the hypothesis survived repeated tests using cladistic analysis, and (3) the alternatives were too vaguely phrased, there was no convincing evidence for them, and they failed repeated cladistic testing. The public tends to think that there is a substantial controversy among scientists about the ancestry of birds, partly because the public does not understand cladistics and partly because cladistics is rejected as a method by the opponents of the dinosaur-bird hypothesis.
What, then, is cladistics? Cladistics, or phylogenetic systematics, is a way of analyzing relationships that was first brought to the fore in the late 1960s, although it had been proposed in Germany decades earlier. By the early 1980s, it had demonstrated its practical and theoretical value to enough of the community of systematists that its methods became commonplace in studies of all branches of organisms, in most top scientific journals, and in the National Science Foundation's decisions about awards in systematic biology. Its influence has grown in succeeding years to the point that statements about evolutionary relationships are no longer taken seriously in the community of systematists unless backed by a cladistic analysis. This is true regardless of the type of organism and regardless of whether the postulated relationship is based on morphology, molecules, behavior, or fossils.
There is no guarantee that any given cladogram will not be revised or overturned by further study (new techniques are constantly being developed and revised); they are hypotheses that are meant to be tested, after all. But cladograms, unlike any other kind of evolutionary hypothesis of relationships, are explicit in their methods and the data on which they are based, and are testable. This gives them practical value. And because they restrict evidence to new, unique evolutionary features as a way of determining relationships among closest relatives, they are more consistent theoretically with the expectations of evolution than any other method.
Most people accept, on practical as well as theoretical grounds, that medical imaging (X-rays, CAT scans, and so on) shows what is going on inside a patient. Before X-rays, physicians had to operate (dangerous and painful) or feel around on the outside and infer the patient's condition. With modern medical imaging, physicians can easily see an intestinal blockage, a tumor, or a fracture. The people who object to cladistics, decades after its general adoption, are like doctors who would rather feel around to diagnose the problem. It is not that they are necessarily wrong, but now we have better ways to diagnose ailments. If you were sick, would you rather have your doctor just feel around, or use an imaging technique such as an X-ray? At least as a second opinion?
Another criticism, focused on the widespread use of computers in cladistic analysis, is that cladistics is just "garbage in, garbage out". Not so: the computer does not do the thinking for the scientist. The scientist determines which characters and organisms to choose and which states are primitive and derived. The computer's role is just to do electronically what takes much longer to do by hand: namely, sorting out the shortest and simplest evolutionary "family" trees for further testing. It is exactly analogous to using a calculator instead of pencil and paper to add a long list of figures. And every cladistic analysis contains a list of the characters and organisms used and how the character states were coded, so anyone can run the analysis again - with variations, if desired.
Why the emphasis on methods in an article that is supposed to be an update on the dinosaur-bird hypothesis? Because every couple of months - or so it seems - there is some kind of challenge to the hypothesis, mounted by the same cast of characters. Well, fine; science is built on challenges to what we think we know. But when do we start to decide that a hypothesis is pretty robust to all this testing, and what standards of testing should we require? Although it has been over 25 years since Ostrom put forth the dinosaur-bird hypothesis, its opponents have yet to propose an alternative, testable hypothesis. So far not a single one of these opponents has ever - and I doubt they ever will - come out and said, "here's another animal or group of animals that we propose as closer to birds than the theropod dinosaurs, and here are the reasons." Their hypothesis is simply that the dinosaur-bird hypothesis is wrong. All the proposed similarities of birds and dinosaurs are mistakes and delusions.
Opponents also claim that the dinosaur-bird hypothesis is dogma, apparently on the grounds that those who accept it have not accepted the opponents' arguments for rejecting it. But science does not require unanimity, it does not force agreement, and it does not settle issues by vote. Some geologists went to their graves not accepting that the continents move. Science progresses nonetheless, by the accumulation of evidence and the testing of hypotheses that account for it. Today it is difficult to find an article in geology that begins by allowing that plate tectonics is only one possible model among many other equally plausible ones - even though 40 years ago the theory was hotly contested.
Well, what methods and tests are the anti-theropod critics using? Not cladistics: they do not use cladistics, because every time someone does a cladistic analysis, birds come out most closely related to theropod dinosaurs. The critics often admit their aversion to cladistics, but even when they do not, their papers speak for them: not a single real cladogram has appeared in any of their works.
Okay, we can all agree that any hegemony of method can be challenged. But in science, we do need methods. What, then, do they propose in place of cladistics? The answer is a resounding silence. They will not say what methods they are using, and so it is impossible for anyone to test their statements. Occasionally, they claim that they do not need methods because they have the crucial evidence to falsify the dinosaur-bird hypothesis. Luis Chiappe and I dealt with these objections in several publications, including our 1998 article in Scientific American (Padian and Chiappe 1998a) and a longer, more technical one in Biological Reviews in the same year (Padian and Chiappe 1998b).
There are two larger points of interest here. I am often asked, by other scientists, by reporters, and by members of the public who are just interested in questions about dinosaurs and evolution, "So what is it with these anti-theropod people? It sounds like you are arguing with creationists." And here, especially for the NCSE audience, I would like to demur on this comparison. It is intellectually dissonant to mention these two groups in the same sentence, because obviously the dissenters to the dinosaur-bird hypothesis are competent scientists who accept evolution. But the comparison appears to recur because if you have no alternative hypothesis to test scientifically, and you do not accept the methods of the field yet have no alternative methods that can be used, at some point observers will begin to wonder about the scientific basis for your statements. I think, in fairness to these dissenters, that they hold that evolutionary processes, as they understand them, would not be able to produce birds from dinosaurs; so the evolutionary patterns that we see in cladograms must be wrong.
The second point has to do with public education. Why does the public not understand the methodological basis of this dispute? The answer is two-pronged. First, the reporters assigned to cover the story do not make the issue clear to the public. This is because most of them do not understand it; they think that the dispute is largely motivated by personalities and politics in the absence of definitive evidence. It could be improved if reporters would explain at least a bit about the methods and standards of evidence, as opposed to "he said, she said" journalism. But after all, they are journalists, and we cannot expect them to be scientists too, any more than scientists can be competent reporters.
The second reason, which encompasses the first, is that even though cladistic analysis has been the standard for the field for two decades, it is almost unknown to the general public. Textbooks continue to teach the outworn Linnaean system and to portray taxonomy as some kind of art, instead of as a process that arranges organisms according to scientifically tested hypotheses about the evolutionary changes that produced a variety of descendants from a common ancestor.
What sort of feathers do these dinosaurs have? Well, they have two kinds of integumentary structures. One kind produces a thick, relatively short and dense pelage made up of fibrous, filamentous structures that appear all over the body. These, claim some opponents of the dinosaur-bird hypothesis, are merely collagen (a common connective tissue in skin). However, molecular analysis shows that these structures are made of keratin - and not just any keratin, but the beta-keratin that feathers have (and, equally important, not the alpha-keratin that make up the scales of today's reptiles). Dinosaurs that have this kind of integumentary structure include several coelurosaurian theropods, such as the compsognathid Sinosauropteryx, the therizinosaurid Beipiaosaurus, and the dromaeosaur Saurornithosaurus (listed in order of their closeness to birds). More feathered coelurosaurs continue to be discovered and described in the scientific literature.
The second kind of integument is true feathers, which have a central shaft, two vanes, and barbs. These true feathers are attached to the forelimbs and tail just as the feathers of Archaeopteryx and living birds are. True feathers are found in the oviraptorosaur Caudipteryx and another form, Protarchaeopteryx, which are coelurosaurs. Opponents of the dinosaur-bird hypothesis have claimed that these are merely birds that have given up the ability to fly, but because they have not performed a phylogenetic analysis of any sort, they have no support for this assertion.
Opponents of the dinosaur-bird hypothesis keep publishing objections that are based on alternative interpretations of single features or specimens, which by themselves do not falsify the dinosaur-bird hypothesis. The most recent is a re-interpretation of Longisquama, an enigmatic reptile of undetermined relationship that occurs in the Triassic of Kazakhstan. It has been known for 30 years, but what is most interesting about Longisquama are the long oblong structures that appear to emanate from its vertebral column. Each of these structures has a central stalk that separates two flat, semi-elliptical surfaces. There are no barbs, but there are some features emanating from the stalk, wavy in contour, directed proximally near the base of the stalk and distally near its end. The entire structure is surrounded by a perimeter reminiscent of a rubber band.
The re-interpretation of this specimen as possessing true feathers (Jones and others 2000) was supposed to overturn the dinosaur-bird hypothesis, according to an aggressive press release and statements made for the benefit of the media, but for the most part it just left paleontologists scratching their heads. No one appeared to be postulating Longisquama as the closest relative of birds, so what were we supposed to learn from this publication? Perhaps we were to be admonished that the fossil record is rich enough to contain plenty of surprises, and so we should not be so confident in the dinosaur-bird hypothesis. Okay, caution taken. Now, what is the alternative hypothesis? And what is the method used to frame it?
Well, there is no hypothesis, and there is no method. Two major problems in the re-interpretation of Longisquama indicate the pitfalls of the "alternative" approach. First, the opponents of the dinosaur-bird hypothesis who published this paper asserted that Longisquama was an archosaur, but it is not. Archosaurs (by definition) include birds and crocodiles and all descendants of their closest common ancestor. No analysis yet has placed Longisquama anywhere near this group. Rather, it is apparently somewhere within Sauria, the broad group that includes living lizards and snakes, Sphenodon, crocodiles, birds, and all the descendants of their most recent common ancestor. The specimens preserve too few features to be much more specific. So it is difficult for them to propose that this animal had anything to do with the origin of birds.
The second error is the assertion that Longisquama had true feathers (Reisz and Sues 2000). Reporters found it difficult to get anyone else to agree with this (Stokstad 2000). The two most noted experts on feather structure and development rejected the idea, and one opined that the paper would not have been published in even a third-rate ornithological journal. As noted above, the similarities to feathers are superficial at best. Why, then, did the paper receive such attention in the popular and scientific press? Well, scientific journalism, especially in high-profile journals, is not above a bit of the "Man Bites Dog" mentality; there is competition to report on what seems new and exciting, even in the news sections of peer-reviewed publications.
Let me propose a litmus test. Next time you encounter a newspaper or television story on this or any scientific issue, get to the bottom of it with two questions: (1) What exact hypothesis is being proposed here to supplant another one (and it cannot be simply that the first hypothesis is wrong: we assume that in all tests)? (2) What methods are being used, if not the standard methods in the field, and how do we know that these are better than the standard methods? If and when the opponents of the dinosaur-bird hypothesis manage to give satisfactory answers to these two questions, they will be taken seriously.
What, then, is cladistics? Cladistics, or phylogenetic systematics, is a way of analyzing relationships that was first brought to the fore in the late 1960s, although it had been proposed in Germany decades earlier. By the early 1980s, it had demonstrated its practical and theoretical value to enough of the community of systematists that its methods became commonplace in studies of all branches of organisms, in most top scientific journals, and in the National Science Foundation's decisions about awards in systematic biology. Its influence has grown in succeeding years to the point that statements about evolutionary relationships are no longer taken seriously in the community of systematists unless backed by a cladistic analysis. This is true regardless of the type of organism and regardless of whether the postulated relationship is based on morphology, molecules, behavior, or fossils.
There is no guarantee that any given cladogram will not be revised or overturned by further study (new techniques are constantly being developed and revised); they are hypotheses that are meant to be tested, after all. But cladograms, unlike any other kind of evolutionary hypothesis of relationships, are explicit in their methods and the data on which they are based, and are testable. This gives them practical value. And because they restrict evidence to new, unique evolutionary features as a way of determining relationships among closest relatives, they are more consistent theoretically with the expectations of evolution than any other method.
Cladistics and its Critics
Critics of cladistics (those who still remain), or critics of the dinosaur-bird hypothesis, claim that cladistics has become dogma. To understand how people in the field respond to this complaint, I suggest the following analogy.Most people accept, on practical as well as theoretical grounds, that medical imaging (X-rays, CAT scans, and so on) shows what is going on inside a patient. Before X-rays, physicians had to operate (dangerous and painful) or feel around on the outside and infer the patient's condition. With modern medical imaging, physicians can easily see an intestinal blockage, a tumor, or a fracture. The people who object to cladistics, decades after its general adoption, are like doctors who would rather feel around to diagnose the problem. It is not that they are necessarily wrong, but now we have better ways to diagnose ailments. If you were sick, would you rather have your doctor just feel around, or use an imaging technique such as an X-ray? At least as a second opinion?
Another criticism, focused on the widespread use of computers in cladistic analysis, is that cladistics is just "garbage in, garbage out". Not so: the computer does not do the thinking for the scientist. The scientist determines which characters and organisms to choose and which states are primitive and derived. The computer's role is just to do electronically what takes much longer to do by hand: namely, sorting out the shortest and simplest evolutionary "family" trees for further testing. It is exactly analogous to using a calculator instead of pencil and paper to add a long list of figures. And every cladistic analysis contains a list of the characters and organisms used and how the character states were coded, so anyone can run the analysis again - with variations, if desired.
Why the emphasis on methods in an article that is supposed to be an update on the dinosaur-bird hypothesis? Because every couple of months - or so it seems - there is some kind of challenge to the hypothesis, mounted by the same cast of characters. Well, fine; science is built on challenges to what we think we know. But when do we start to decide that a hypothesis is pretty robust to all this testing, and what standards of testing should we require? Although it has been over 25 years since Ostrom put forth the dinosaur-bird hypothesis, its opponents have yet to propose an alternative, testable hypothesis. So far not a single one of these opponents has ever - and I doubt they ever will - come out and said, "here's another animal or group of animals that we propose as closer to birds than the theropod dinosaurs, and here are the reasons." Their hypothesis is simply that the dinosaur-bird hypothesis is wrong. All the proposed similarities of birds and dinosaurs are mistakes and delusions.
Opponents also claim that the dinosaur-bird hypothesis is dogma, apparently on the grounds that those who accept it have not accepted the opponents' arguments for rejecting it. But science does not require unanimity, it does not force agreement, and it does not settle issues by vote. Some geologists went to their graves not accepting that the continents move. Science progresses nonetheless, by the accumulation of evidence and the testing of hypotheses that account for it. Today it is difficult to find an article in geology that begins by allowing that plate tectonics is only one possible model among many other equally plausible ones - even though 40 years ago the theory was hotly contested.
Well, what methods and tests are the anti-theropod critics using? Not cladistics: they do not use cladistics, because every time someone does a cladistic analysis, birds come out most closely related to theropod dinosaurs. The critics often admit their aversion to cladistics, but even when they do not, their papers speak for them: not a single real cladogram has appeared in any of their works.
Okay, we can all agree that any hegemony of method can be challenged. But in science, we do need methods. What, then, do they propose in place of cladistics? The answer is a resounding silence. They will not say what methods they are using, and so it is impossible for anyone to test their statements. Occasionally, they claim that they do not need methods because they have the crucial evidence to falsify the dinosaur-bird hypothesis. Luis Chiappe and I dealt with these objections in several publications, including our 1998 article in Scientific American (Padian and Chiappe 1998a) and a longer, more technical one in Biological Reviews in the same year (Padian and Chiappe 1998b).
There are two larger points of interest here. I am often asked, by other scientists, by reporters, and by members of the public who are just interested in questions about dinosaurs and evolution, "So what is it with these anti-theropod people? It sounds like you are arguing with creationists." And here, especially for the NCSE audience, I would like to demur on this comparison. It is intellectually dissonant to mention these two groups in the same sentence, because obviously the dissenters to the dinosaur-bird hypothesis are competent scientists who accept evolution. But the comparison appears to recur because if you have no alternative hypothesis to test scientifically, and you do not accept the methods of the field yet have no alternative methods that can be used, at some point observers will begin to wonder about the scientific basis for your statements. I think, in fairness to these dissenters, that they hold that evolutionary processes, as they understand them, would not be able to produce birds from dinosaurs; so the evolutionary patterns that we see in cladograms must be wrong.
The second point has to do with public education. Why does the public not understand the methodological basis of this dispute? The answer is two-pronged. First, the reporters assigned to cover the story do not make the issue clear to the public. This is because most of them do not understand it; they think that the dispute is largely motivated by personalities and politics in the absence of definitive evidence. It could be improved if reporters would explain at least a bit about the methods and standards of evidence, as opposed to "he said, she said" journalism. But after all, they are journalists, and we cannot expect them to be scientists too, any more than scientists can be competent reporters.
The second reason, which encompasses the first, is that even though cladistic analysis has been the standard for the field for two decades, it is almost unknown to the general public. Textbooks continue to teach the outworn Linnaean system and to portray taxonomy as some kind of art, instead of as a process that arranges organisms according to scientifically tested hypotheses about the evolutionary changes that produced a variety of descendants from a common ancestor.
Recent Developments in Bird Evolution
Recent developments illustrate some problems faced by the opponents of the dinosaur-bird hypothesis. Most readers will have heard that several kinds of feathered dinosaurs have been recently discovered in the Early Cretaceous deposits of Liaoning Province, China. They belong to several distinct groups within the broader group of coelurosaurian dinosaurs - the group to which all systematic analyses conclude that birds belong.What sort of feathers do these dinosaurs have? Well, they have two kinds of integumentary structures. One kind produces a thick, relatively short and dense pelage made up of fibrous, filamentous structures that appear all over the body. These, claim some opponents of the dinosaur-bird hypothesis, are merely collagen (a common connective tissue in skin). However, molecular analysis shows that these structures are made of keratin - and not just any keratin, but the beta-keratin that feathers have (and, equally important, not the alpha-keratin that make up the scales of today's reptiles). Dinosaurs that have this kind of integumentary structure include several coelurosaurian theropods, such as the compsognathid Sinosauropteryx, the therizinosaurid Beipiaosaurus, and the dromaeosaur Saurornithosaurus (listed in order of their closeness to birds). More feathered coelurosaurs continue to be discovered and described in the scientific literature.
The second kind of integument is true feathers, which have a central shaft, two vanes, and barbs. These true feathers are attached to the forelimbs and tail just as the feathers of Archaeopteryx and living birds are. True feathers are found in the oviraptorosaur Caudipteryx and another form, Protarchaeopteryx, which are coelurosaurs. Opponents of the dinosaur-bird hypothesis have claimed that these are merely birds that have given up the ability to fly, but because they have not performed a phylogenetic analysis of any sort, they have no support for this assertion.
Opponents of the dinosaur-bird hypothesis keep publishing objections that are based on alternative interpretations of single features or specimens, which by themselves do not falsify the dinosaur-bird hypothesis. The most recent is a re-interpretation of Longisquama, an enigmatic reptile of undetermined relationship that occurs in the Triassic of Kazakhstan. It has been known for 30 years, but what is most interesting about Longisquama are the long oblong structures that appear to emanate from its vertebral column. Each of these structures has a central stalk that separates two flat, semi-elliptical surfaces. There are no barbs, but there are some features emanating from the stalk, wavy in contour, directed proximally near the base of the stalk and distally near its end. The entire structure is surrounded by a perimeter reminiscent of a rubber band.
The re-interpretation of this specimen as possessing true feathers (Jones and others 2000) was supposed to overturn the dinosaur-bird hypothesis, according to an aggressive press release and statements made for the benefit of the media, but for the most part it just left paleontologists scratching their heads. No one appeared to be postulating Longisquama as the closest relative of birds, so what were we supposed to learn from this publication? Perhaps we were to be admonished that the fossil record is rich enough to contain plenty of surprises, and so we should not be so confident in the dinosaur-bird hypothesis. Okay, caution taken. Now, what is the alternative hypothesis? And what is the method used to frame it?
Well, there is no hypothesis, and there is no method. Two major problems in the re-interpretation of Longisquama indicate the pitfalls of the "alternative" approach. First, the opponents of the dinosaur-bird hypothesis who published this paper asserted that Longisquama was an archosaur, but it is not. Archosaurs (by definition) include birds and crocodiles and all descendants of their closest common ancestor. No analysis yet has placed Longisquama anywhere near this group. Rather, it is apparently somewhere within Sauria, the broad group that includes living lizards and snakes, Sphenodon, crocodiles, birds, and all the descendants of their most recent common ancestor. The specimens preserve too few features to be much more specific. So it is difficult for them to propose that this animal had anything to do with the origin of birds.
The second error is the assertion that Longisquama had true feathers (Reisz and Sues 2000). Reporters found it difficult to get anyone else to agree with this (Stokstad 2000). The two most noted experts on feather structure and development rejected the idea, and one opined that the paper would not have been published in even a third-rate ornithological journal. As noted above, the similarities to feathers are superficial at best. Why, then, did the paper receive such attention in the popular and scientific press? Well, scientific journalism, especially in high-profile journals, is not above a bit of the "Man Bites Dog" mentality; there is competition to report on what seems new and exciting, even in the news sections of peer-reviewed publications.
Let me propose a litmus test. Next time you encounter a newspaper or television story on this or any scientific issue, get to the bottom of it with two questions: (1) What exact hypothesis is being proposed here to supplant another one (and it cannot be simply that the first hypothesis is wrong: we assume that in all tests)? (2) What methods are being used, if not the standard methods in the field, and how do we know that these are better than the standard methods? If and when the opponents of the dinosaur-bird hypothesis manage to give satisfactory answers to these two questions, they will be taken seriously.
References
Jones TD, Ruben JA, Martin LD, Kurochkin EN, Feduccia A, Maderson PFA, Hillenius WJ, Geist NR, Alifanov V. Nonavian feathers in a Late Triassic archosaur. Science 2000; 288: 2202-5.Ostrom JH. The ancestry of birds. Nature 1973; 242: 136.
Padian K and Chiappe LM. The origin of birds and their flight. Scientific American 1998 Feb; 28-37.
Padian K and Chiappe LM. The origin and early evolution of birds. Biological Reviews 1998; 73: 1-42.
Reisz RR, Sues H-D. The "feathers" of Longisquama. Nature 2000; 408: 428.
Stokstad E. Feathers, or flight of fancy? Science 2000; 288: 2124-5.
The Origin of Whales and the Power of Independent Evidence
How do you convince a creationist that a fossil is a transitional fossil? Give up? It is a trick question. You cannot do it. There is no convincing someone who has his mind made up already. But sometimes, it is even worse. Sometimes, when you point out a fossil that falls into the middle of a gap and is a superb morphological and chronological intermediate, you are met with the response: "Well, now you have two gaps where you only had one before! You are losing ground!"
One of the favorite anti-evolutionist challenges to the existence of transitional fossils is the supposed lack of transitional forms in the evolution of the whales. Duane Gish of the Institute for Creation Research (ICR) regularly trots out the "bossie-to-blowhole" transition to ridicule the idea that whales could have evolved from terrestrial, hooved ancestors.
Of course, for many years the fossil record for the whales was quite spotty, but now there are numerous transitional forms that illustrate the pathway of whale evolution.
Recent discoveries of fossil whales provide the evidence that will convince an honest skeptic. However, evolutionary biology predicts more than just the existence of fossil ancestors with certain characteristics — it also predicts that all other biological disciplines should also revels patterns of similarity among whales, their ancestors, and other mammals correlated with evolutionary relatedness between groups. It should be no surprise that this is what we find, and since the findings in one biological discipline, say biochemistry, is derived without reference to the findings in another, say comparative anatomy, scientists consider these different fields to provide independent evidence of the evolution of whales. As expected, these independent lines of evidence all confirm the pattern of whale evolution that we would anticipate in the fossil record.
To illustrate this approach, I will present the evidence from multiple fields for the origin of the whales from terrestrial mammals. This paper will examine mutually reinforcing evidence from nine independent areas of research. Of course, as a starting point, we need to describe what makes a whale a whale.
But a whale is a very specialized mammal with many unique characters that are not shared with other mammals — many of these are not even shared with other marine mammals such as sirenians (manatees and dugongs) and pinnipeds (seals, sea lions, and walruses). For example, whales have streamlined bodies that are thick and rounded, unlike the generally slim, elongated bodies of fishes. A whale's tail has horizontal flukes, which are its sole means of propulsion through the water. The dorsal fin is stiffened by connective tissue, but is fleshy and entirely without supporting bones.
The neck vertebrae of the whale are shortened and at least partly fused into a single bony mass. The vertebrae behind the neck are numerous and very similar to one another; the bony processes that connect the vertebrae are greatly reduced, allowing the back to be very flexible and to produce powerful thrusts from the tail flukes. The flippers that allow the whale to steer are composed of flattened and shortened arm bones, flat, disk-like wrist bones, and multiple elongated fingers. The elbow joint is virtually immobile, making the flipper rigid. In the shoulder girdle, the shoulder blade is flattened, and there is no clavicle. A few species of whales still possess a vestigial pelvis, and some have greatly reduced and nonfunctional hindlimbs.
The rib cage is very mobile — in some species, the ribs are entirely separated from the vertebral column — which allows the chest to expand greatly when the whale is breathing in and allows the thorax to compress at depth when the whale is diving deeply.
The skull also has a set of features unique among mammals. The jaws extend forward, giving whales their characteristically long head, and the two front-most bones of the upper jaw (the maxillary and premaxillary) are "telescoped" rearward, sometimes entirely covering the top of the skull. The rearward migration of these bones is the process by which the nasal openings have moved to the top of the skull, creating blowholes and shifting the brain and the auditory apparatus to the back of the skull. The odontocetes (toothed whales) have a single blowhole, while the mysticetes (baleen whales) have paired blowholes.
In the odontocetes, there is a pronounced asymmetry in the telescoped bones and the blowhole that provides a natural means of classification. Although teeth often occur in fetal mysticetes, only odontocetes exhibit teeth as adults. These teeth are always simple cones or pegs; they are not differentiated by region or function as teeth are in other mammals. (Whales cannot chew their food; it is ground up instead in a forestomach, or muscular crop, containing stones.)
Unlike the rest of the mammals, whales have no tear glands, no skin glands, and no olfactory sense. Their hearing is acute but the ear has no external opening. Hearing occurs via vibrations transmitted to a heavy, shell-like bone formed by fusion of skull bones (the periotic and auditory bullae).
These, then, are the major features of whales. Some clearly show the distinctive adaptations imposed on whales by their commitment to marine living; others clearly link the whales to their terrestrial ancestors. Others show the traces of descent from a terrestrial ancestor in common with several ancient and modern species. From all these features together, we can reconstruct the pathway that whale evolution took from a terrestrial ancestor to a modern whale confined to deep oceans.
Later, Flower (1883) recognized that the whales have persistent rudimentary and vestigial features characteristic of terrestrial mammals, thus confirming that the direction of descent was from terrestrial to marine species. On the basis of morphology, Flower also linked whales with the ungulates; he seems to have been the first person to do so.
Early in the 20th century, Eberhard Fraas and Charles Andrews suggested that creodonts (primitive carnivores, now extinct) were the ancestors of whales (Barnes 1984). Later, WD Matthew of the American Museum of Natural History postulated that whales descended from insectivores, but his idea never gained much support (Barnes 1984). Later still, Everhard Johannes Slijper tried to combine the two ideas, claiming that whales descended from what Barnes aptly called "creodonts-cum-insectivores". However, no such animal has ever been found. More recently, Van Valen (1966) and Szalay (1969) associated early whales with mesonychid condylarths (a now-extinct group of primitive carnivorous ungulates, none bigger than a wolf) on the basis of dental characters. More recent evidence confirms their assessment. Thus Flower was basically right.
Zhou and others (1995) published this reconstruction of the skull of Sinonyx jiashanensis (redrawn for RNCSE by Janet Dreyer).
Gingrich and others (1983) published this reconstruction of the skull of Pakicetus inachus (redrawn for RNCSE by Janet Dreyer).
A well-preserved cranium shows that Pakicetus was definitely a cetacean with a narrow braincase, a high, narrow sagittal crest, and prominent lambdoidal crests. Gingerich and others (1983) reconstructed a composite skull that was about 35 centimeters long. Pakicetus did not hear well underwater. Its skull had neither dense tympanic bullae nor sinuses isolating the left auditory area from the right one — an adaptation of later whales that allows directional hearing under water and prevents transmission of sounds through the skull (Gingerich and others 1983). All living whales have foam-filled sinuses along with dense tympanic bullae that create an impedance contrast so they can separate sounds arriving from different directions. There is also no evidence in Pakicetus of vascularization of the middle ear, which is necessary to regulate the pressure within the middle ear during diving (Gingerich and others 1983). Therefore, Pakicetus was probably incapable of achieving dives of any significant depth. This paleontological assessment of the ecological niche of Pakicetus is entirely consistent with the geochemical and paleoenvironmental evidence. When it came to hearing, Pakicetus was more terrestrial than aquatic, but the shape of its skull was definitely cetacean, and its teeth were between the ancestral and modern states.
The forelimbs were also intermediate in both structure and function. The ulna and the radius were strong and capable of carrying the weight of the animal on land. The strong elbow was strong but it was inclined rearward, making possible rearward thrusts of the forearm for swimming. However, the wrists, unlike those of modern whales, were flexible.
It is obvious from the anatomy of the spinal column that Ambulocetus must have swum with its spine swaying up and down, propelled by its back feet, oriented to the rear. As with other aquatic mammals using this method of swimming, the back feet were quite large. Unusually, the toes of the back feet terminated in hooves, thus advertising the ungulate ancestry of the animal. The only tail vertebra found is long, making it likely that the tail was also long. The cervical vertebrae were relatively long, compared to those of modern whales; Ambulocetus must have had a flexible neck.
Ambulocetus's skull was quite cetacean (Novacek 1994). It had a long muzzle, teeth that were very similar to later archaeocetes, a reduced zygomatic arch, and a tympanic bulla (which supports the eardrum) that was poorly attached to the skull. Although Ambulocetus apparently lacked a blowhole, the other skull features qualify Ambulocetus as a cetacean. The post-cranial features are clearly in transitional adaptation to the aquatic environment. Thus Ambulocetus is best described as an amphibious, sea-lion-sized fish-eater that was not yet totally disconnected from the terrestrial life of its ancestors.
Gingrich and others (1994) published this reconstruction of the skeleton of Rodhocetus kasrani (redrawn for RNCSE by Janet Dreyer).
Elsewhere along the spine, the four large sacral vertebrae were unfused. This gave the spine more flexibility and allowed a more powerful thrust while swimming. It is also likely that Rodhocetus had a tail fluke, although such a feature is not preserved in the known fossils: it possessed features — shortened cervical vertebrae, heavy and robust proximal tail vertebrae, and large dorsal spines on the lumbar vertebrae for large tail and other axial muscle attachments — that are associated in modern whales with the development and use of tail flukes. All in all, Rodhocetus must have been a very good tail-swimmer, and it is the earliest fossil whale committed to this manner of swimming.
The pelvis of Rodhocetus was smaller than that of its predecessors, but it was still connected to the sacral vertebrae, meaning that Rodhocetus could still walk on land to some degree. However, the ilium of the pelvis was short compared to that of the mesonychids, making for a less powerful muscular thrust from the hip during walking, and the femur was about 1/3 shorter than Ambulocetus’s, so Rodhocetus probably could not get around as well on land as its predecessors (Gingerich and others 1994).
Rodhocetus's skull was rather large compared to the rest of the skeleton. The premaxillae and dentaries had extended forward even more than its predecessors’, elongating the skull and making it even more cetacean. The molars have higher crowns than in earlier whales and are greatly simplified. The lower molars are higher than they are wide. There is a reduced differentiation among the teeth. For the first time, the nostrils have moved back along the snout and are located above the canine teeth, showing blowhole evolution. The auditory bullae are large and made of dense bone (characteristics unique to cetaceans), but they apparently did not contain the sinuses typical of later whales, making it questionable whether Rodhocetus possessed directional hearing underwater.
Overall, Rodhocetus showed improvements over earlier whales by virtue of its deep, slim thorax, longer head, greater vertebral flexibility, and expanded tail-related musculature. The increase in flexibility and strength in the back and tail with the accompanying decrease in the strength and size of the limbs indicated that it was a good tail-swimmer with a reduced ability to walk on land.
What makes Basilosaurus a particularly interesting whale, however, is the distinctive anatomy of its hind limbs (Gingerich and others 1990). It had a nearly complete pelvic girdle and set of hindlimb bones. The limbs were too small for effective propulsion, less than 60 cm long on this 15-meter-long animal, and the pelvic girdle was completely isolated from the spine so that weight-bearing was impossible. Reconstructions of the animal have placed its legs external to the body — a configuration that would represent an important intermediate form in whale evolution.
Although no tail fluke has ever been found (since tail flukes contain no bones and are unlikely to fossilize), Gingerich and others (1990) noted that Basilosaurus's vertebral column shares characteristics of whales that do have tail flukes. The tail and cervical vertebrae are shorter than those of the thoracic and lumbar regions, and Gingerich and others (1990) take these vertebral proportions as evidence that Basilosaurus probably also had a tail fluke.
Further evidence that Basilosaurus spent most of its time in the water comes from another important change in the skull. This animal had a large single nostril that had migrated a short distance back to a point corresponding to the back third of the dental array. The movement from the forward extreme of the snout to the a position nearer the top of the head is characteristic of only those mammals that live in marine or aquatic environments.
Gingrich and Uhen (1996) published this reconstruction of the skeleton of Dorudon atrox (redrawn for RNCSE by Janet Dreyer).
Basilosaurus and Dorudon were fully aquatic whales (like Basilosaurus, Dorudon had very small hind limbs that may have projected slightly beyond the body wall). They were no longer tied to the land; in fact, they would not have been able to move around on land at all. Their size and their lack of limbs that could support their weight made them obligate aquatic mammals, a trend that is elaborated and reinforced by subsequent whale taxa.
Clearly, even if we look only at the paleontological evidence, the creationist claim of "No fossil intermediates!" is wrong. In fact, in the case of whales, we have several, beautifully arranged in morphological and chronological order.
In summarizing the paleontological evidence, we have noted the consistent changes that indicate a series of adaptations from more terrestrial to more aquatic environments as we move from the most ancestral to the most recent species. These changes affect the shape of the skull, the shape of the teeth, the position of the nostrils, the size and structure of both the forelimbs and the hindlimbs, the size and shape of the tail, and the structure of the middle ear as it relates to directional hearing underwater and diving. The paleontological evidence records a history of increasing adaptation to life in the water — not just to any way of life in the water, but to life as lived by contemporary whales.
Another example involves the incus (the "anvil" of the middle ear). The incus of Pakicetus, preserved in at least one specimen, is morphologically intermediate in all characters between the incus of modern whales and that of modern artiodactyls (Thewissen and Hussain 1993). Additionally, the joint between the malleus (hammer) and incus of most mammals is oriented at an angle between the middle and the front of the animal (rostromedially), while in modern whales and in ungulates, it is oriented at an angle between the side and the front (rostrolaterally). In Pakicetus, the first fossil cetacean, the joint is oriented rostrally (intermediate in position between the ancestral and derived conditions). Thus the joint has clearly rotated toward the middle from the ancestral condition in terrestrial mammals (Thewissen and Hussain 1993); Pakicetus provides us with a snapshot of the transition.
Molecular studies by Goodman and others (1985) show that whales are more closely related to the ungulates than they are to all other mammals — a result consistent with evolutionary expectations. These studies examined myoglobin, lens alpha-crystallin A, and cytochrome c in a study of 46 different species of mammals. Miyamoto and Goodman (1986) later expanded the number of protein sequences by including alpha- and beta- hemoglobins and ribonuclease; they also increased the number of mammals included in the study to 72. The results were the same: the whales clearly are included among the ungulates. Other molecular studies on a variety of genes, proteins, and enzymes by Irwin and others (1991), Irwin and Arnason (1994), Milinkovitch (1992), Graur and Higgins (1994), Gatesy and others (1996), and Shimamura and others (1997) also identified the whales as closely related to the artiodactyls, although there are differences in the details among the studies.
By placing whales close to, and even firmly within, the Artiodactyls, these molecular studies confirm the predictions made by evolutionary theory. This pattern of biochemical similarities must be present if the whales and the ungulates, especially the Artiodactyls, share a close common ancestor. The fact that these similarities are present is therefore strong evidence for the common ancestry of whales and ungulates.
Modern whales often retain rod-like vestiges of pelvic bones, femora, and tibiae, all embedded within the musculature of their body walls. These bones are more pronounced in earlier species and less pronounced in later species. As the example of Basilosaurus shows, whales of intermediate age have intermediate-sized vestigial pelves and rear limb bones.
Whales also retain a number of vestigial structures in their organs of sensation. Modern whales have only vestigial olfactory nerves. Furthermore, in modern whales the auditory meatus (the exterior opening of the ear canal) is closed. In many, it is merely the size of a thin piece of string, about 1 mm in diameter, and often pinched off about midway. All whales have a number of small muscles devoted to nonexistent external ears, which are apparently a vestige of a time when they were able to move their ears — a behavior typically used by land animals for directional hearing.
The diaphragm in whales is vestigial and has very little muscle. Whales use the outward movement of the ribs to fill their lungs with air. Finally, Gould (1983) reported several occurrences of captured sperm whales with visible, protruding hind limbs. Similarly, dolphins have been spotted with tiny pelvic fins, although they probably were not supported by limb bones as in those rare sperm whales. And some whales, such as belugas, possess rudimentary ear pinnae — a feature that can serve no purpose in an animal with no external ear and that can reduce the animal's swimming efficiency by increasing hydrodynamic drag while swimming.
Although this list is by no means exhaustive, it is nonetheless clear that the whales have a wealth of vestigial features left over from their terrestrial ancestors.
Second, the embryology of the whale, examined in detail, also provides evidence for its terrestrial ancestry. As embryos no less than as adult animals, whales are junkyards, as it were, of old, discarded features that are of no further use to them. Many whales, while still in the womb, begin to develop body hair. Yet no modern whales retain any body hair after birth, except for some snout hairs and hairs around their blowholes used as sensory bristles in a few species. The fact that whales possess the genes for producing body hair shows that their ancestors had body hair. In other words, their ancestors were ordinary mammals.
In many embryonic whales, external hind limb buds are visible for a time but thendisappear as the whale grows larger. Also visible in the embryo are rudimentary ear pinnae, which disappear before birth (except in those that carry them as rare atavisms). And, in some whales, the olfactory lobes of the brain exist only in the fetus. The whale embryo starts off with its nostrils in the usual place for mammals, at the tip of the snout. But during development, the nostrils migrate to their final place at the top of the head to form the blowhole (or blowholes).
We can also understand evolution within the whales via their embryology. We know that the baleen whales evolved from the toothed whales: some embryos of the baleen whales begin to develop teeth. As with body hair, the teeth disappear before birth. Since there is no use for teeth in the womb, only inheritance from a common ancestor makes any sense; there is no reason for the intelligent designer or special creator to provide embryonic whales with teeth. So we have yet another independent field in complete accord with the overall thesis — that whales possess features that connect them with terrestrial mammalian ancestors, in particular the hoofed mammals.
The morphology of Sinonyx indicates that it was fully terrestrial. It should be no surprise, therefore, that its fossils are found associated with the fossils of other terrestrial animals. Pakicetus probably spent a lot of time in the water in search of food. Although the mammalian fauna found with Pakicetus consists of rodents, bats, various artiodactyls, perissodactyls and probiscideans, and even a primate (Gingerich and others 1983), there are also aquatic animals such as snails, fish, turtles and crocodilians. Moreover, the sediment associated with Pakicetus shows evidence of streaming or flowing, usually associated with soils that are carried by water. The paleoenvironmental evidence thus clearly shows that Pakicetus lived in the low-lying wet terrestrial environment, making occasional excursions into fresh water. Interestingly, both deciduous and permanent teeth of the animal are found in these sediments with about the same frequency, supporting the idea that Pakicetus gave birth on the land.
The sediments in which Ambulocetus was found contain leaf impressions as well as fossils of the turret-snail Turritella and other marine mollusks. Clearly, the presence of such fossils must mean that the Ambulocetus fossil was found in what was once a shallow sea — although leaves can be washed into the sea and fossilize there, marine mollusks would not be found on the land.
Rodhocetus is found in green shales deposited in the deep-neritic zone (equivalent to the outer part of the continental shelf). Because green shales are associated with fairly low-oxygen bottom waters, Rodhocetus must have lived at a greater water depth than any previous cetacean. The fact that it is found in association with planktonic foraminiferans and other microfossils agrees with this determination of water depth. Basilosaurus and Dorudon have been found in a variety of sediment types (Kellogg 1936), indicating that they were wide-ranging and capable of living in deep as well as shallow water.
From the paleoenvironmental evidence, we can clearly see that, as whales evolved, they made their way into deeper water and became progressively liberated from the terrestrial and near-shore environments.
During the Eocene, most of the areas in which fossils of the later whales have been found were fairly close to one another. In fact, most of them are along the outer margin of an ancient sea called the Tethys, the remnants of which today are the Mediterranean, the Caspian, the Black, and the Aral Seas. The biogeographic distribution of fossil whales matches the pattern predicted by evolution: whales are initially found in a rather small geographic area and did not become distributed throughout the world until after they evolved into fully aquatic animals that were no longer tied to the land.
In the specific case of whales, the swimming reptiles of the world's oceans could no longer keep the mammals at bay. Before the late-Cretaceous extinctions, the Mesozoic marine reptiles such as the plesiosaurs, ichthyosaurs, mosasaurs, and marine crocodiles might well have feasted upon any mammal that strayed off shore in search of food. Once those predators were gone, the evolution quickly produced mammals, including whales, that were as at home in the seas as they once were on land. The transition took some 10-15 million years to produce fully aquatic, deep-diving whales with directional underwater hearing. Evolution predicts that whales could not have successfully appeared and radiated before the Eocene, and that mammals should have radiated into marine environments as they did into a wide variety of other environments vacated by the reptiles at the end of the Cretaceous.
One of the favorite anti-evolutionist challenges to the existence of transitional fossils is the supposed lack of transitional forms in the evolution of the whales. Duane Gish of the Institute for Creation Research (ICR) regularly trots out the "bossie-to-blowhole" transition to ridicule the idea that whales could have evolved from terrestrial, hooved ancestors.
There simply are no transitional forms in the fossil record between the marine mammals and their supposed land mammal ancestors . . . It is quite entertaining, starting with cows, pigs, or buffaloes, to attempt to visualize what the intermediates may have looked life. Starting with a cow, one could even imagine one line of descent which prematurely became extinct, due to what might be called an “udder failure” (Gish 1985: 78-9).
Of course, for many years the fossil record for the whales was quite spotty, but now there are numerous transitional forms that illustrate the pathway of whale evolution.
Recent discoveries of fossil whales provide the evidence that will convince an honest skeptic. However, evolutionary biology predicts more than just the existence of fossil ancestors with certain characteristics — it also predicts that all other biological disciplines should also revels patterns of similarity among whales, their ancestors, and other mammals correlated with evolutionary relatedness between groups. It should be no surprise that this is what we find, and since the findings in one biological discipline, say biochemistry, is derived without reference to the findings in another, say comparative anatomy, scientists consider these different fields to provide independent evidence of the evolution of whales. As expected, these independent lines of evidence all confirm the pattern of whale evolution that we would anticipate in the fossil record.
To illustrate this approach, I will present the evidence from multiple fields for the origin of the whales from terrestrial mammals. This paper will examine mutually reinforcing evidence from nine independent areas of research. Of course, as a starting point, we need to describe what makes a whale a whale.
What is a whale?
A whale is first and foremost, a mammal — a warm-blooded vertebrate that uses its high metabolism to generate heat and regulate its internal temperature. Female whales bear live young, which they nurse from mammary glands. Although adult whales have no covering of body hair, they acquire body hair temporarily as fetuses, and some adult whales have sensory bristles around their mouths. These features are unequivocally mammalian.But a whale is a very specialized mammal with many unique characters that are not shared with other mammals — many of these are not even shared with other marine mammals such as sirenians (manatees and dugongs) and pinnipeds (seals, sea lions, and walruses). For example, whales have streamlined bodies that are thick and rounded, unlike the generally slim, elongated bodies of fishes. A whale's tail has horizontal flukes, which are its sole means of propulsion through the water. The dorsal fin is stiffened by connective tissue, but is fleshy and entirely without supporting bones.
The neck vertebrae of the whale are shortened and at least partly fused into a single bony mass. The vertebrae behind the neck are numerous and very similar to one another; the bony processes that connect the vertebrae are greatly reduced, allowing the back to be very flexible and to produce powerful thrusts from the tail flukes. The flippers that allow the whale to steer are composed of flattened and shortened arm bones, flat, disk-like wrist bones, and multiple elongated fingers. The elbow joint is virtually immobile, making the flipper rigid. In the shoulder girdle, the shoulder blade is flattened, and there is no clavicle. A few species of whales still possess a vestigial pelvis, and some have greatly reduced and nonfunctional hindlimbs.
The rib cage is very mobile — in some species, the ribs are entirely separated from the vertebral column — which allows the chest to expand greatly when the whale is breathing in and allows the thorax to compress at depth when the whale is diving deeply.
The skull also has a set of features unique among mammals. The jaws extend forward, giving whales their characteristically long head, and the two front-most bones of the upper jaw (the maxillary and premaxillary) are "telescoped" rearward, sometimes entirely covering the top of the skull. The rearward migration of these bones is the process by which the nasal openings have moved to the top of the skull, creating blowholes and shifting the brain and the auditory apparatus to the back of the skull. The odontocetes (toothed whales) have a single blowhole, while the mysticetes (baleen whales) have paired blowholes.
In the odontocetes, there is a pronounced asymmetry in the telescoped bones and the blowhole that provides a natural means of classification. Although teeth often occur in fetal mysticetes, only odontocetes exhibit teeth as adults. These teeth are always simple cones or pegs; they are not differentiated by region or function as teeth are in other mammals. (Whales cannot chew their food; it is ground up instead in a forestomach, or muscular crop, containing stones.)
Unlike the rest of the mammals, whales have no tear glands, no skin glands, and no olfactory sense. Their hearing is acute but the ear has no external opening. Hearing occurs via vibrations transmitted to a heavy, shell-like bone formed by fusion of skull bones (the periotic and auditory bullae).
These, then, are the major features of whales. Some clearly show the distinctive adaptations imposed on whales by their commitment to marine living; others clearly link the whales to their terrestrial ancestors. Others show the traces of descent from a terrestrial ancestor in common with several ancient and modern species. From all these features together, we can reconstruct the pathway that whale evolution took from a terrestrial ancestor to a modern whale confined to deep oceans.
Thinking about the ancestry of the whale
In 1693, John Ray recorded his realization that whales are mammals based on the similarity of whales to terrestrial mammals (Barnes 1984). The pre-Darwinian scientific discussion revolved around whether whales were descended from or ancestral to terrestrial mammals. Darwin (1859) suggested that whales arose from bears, sketching a scenario in which selective pressures might cause bears to evolve into whales; embarrassed by criticism, he removed his hypothetical swimming bears from later editions of the Origin (Gould 1995).Later, Flower (1883) recognized that the whales have persistent rudimentary and vestigial features characteristic of terrestrial mammals, thus confirming that the direction of descent was from terrestrial to marine species. On the basis of morphology, Flower also linked whales with the ungulates; he seems to have been the first person to do so.
Early in the 20th century, Eberhard Fraas and Charles Andrews suggested that creodonts (primitive carnivores, now extinct) were the ancestors of whales (Barnes 1984). Later, WD Matthew of the American Museum of Natural History postulated that whales descended from insectivores, but his idea never gained much support (Barnes 1984). Later still, Everhard Johannes Slijper tried to combine the two ideas, claiming that whales descended from what Barnes aptly called "creodonts-cum-insectivores". However, no such animal has ever been found. More recently, Van Valen (1966) and Szalay (1969) associated early whales with mesonychid condylarths (a now-extinct group of primitive carnivorous ungulates, none bigger than a wolf) on the basis of dental characters. More recent evidence confirms their assessment. Thus Flower was basically right.
The evidence
The evidence that whales descended from terrestrial mammals is here divided into nine independent parts: paleontological, morphological, molecular biological, vestigial, embryological, geochemical, paleoenvironmental, paleobiogeographical, and chronological. Although my summary of the evidence is not exhaustive, it shows that the current view of whale evolution is supported by scientific research in several distinct disciplines.1. Paleontological evidence
The paleontological evidence comes from studying the fossil sequence from terrestrial mammals through more and more whale-like forms until the appearance of modern whales. Although the early whales (Archaeocetes) exhibit greater diversity than I have space to discuss here, the examples in this section represent the trends that we see in this taxon. Although there are two modern suborders of whales (Odontocetes and Mysticetes), this discussion will focus on the origin of the whales as an order of mammals, and set aside the issues related to the diversification into suborders.Sinonyx
We start with Sinonyx, a wolf-sized mesonychid (a primitive ungulate from the order Condylarthra, which gave rise to artiodactyls, perissodactyls, proboscideans, and so on) from the late Paleocene, about 60 million years ago. The characters that link Sinonyx to the whales, thus indicating that they are relatives, include an elongated muzzle, an enlarged jugular foramen, and a short basicranium (Zhou and others 1995). The tooth count was the primitive mammalian number (44); the teeth were differentiated as are the heterodont teeth of today's mammals. The molars were very narrow shearing teeth, especially in the lower jaw, but possessed multiple cusps. The elongation of the muzzle is often associated with hunting fish — all fish-hunting whales, as well as dolphins, have elongated muzzles. These features were atypical of mesonychids, indicating that Sinonyx was already developing the adaptations that later became the basis of the whales' specialized way of life.Zhou and others (1995) published this reconstruction of the skull of Sinonyx jiashanensis (redrawn for RNCSE by Janet Dreyer).
Pakicetus
The next fossil in the sequence, Pakicetus, is the oldest cetacean, and the first known archaeocete. It is from the early Eocene of Pakistan, about 52 million years ago (Gingerich and others 1983). Although it is known only from fragmentary skull remains, those remains are very diagnostic, and they are definitely intermediate between Sinonyxand later whales. This is especially the case for the teeth. The upper and lower molars, which have multiple cusps, are still similar to those of Sinonyx, but the premolars have become simple triangular teeth composed of a single cusp serrated on its front and back edges. The teeth of later whales show even more simplification into simple serrated triangles, like those of carnivorous sharks, indicating that Pakicetus's teeth were adapted to hunting fish.Gingrich and others (1983) published this reconstruction of the skull of Pakicetus inachus (redrawn for RNCSE by Janet Dreyer).
A well-preserved cranium shows that Pakicetus was definitely a cetacean with a narrow braincase, a high, narrow sagittal crest, and prominent lambdoidal crests. Gingerich and others (1983) reconstructed a composite skull that was about 35 centimeters long. Pakicetus did not hear well underwater. Its skull had neither dense tympanic bullae nor sinuses isolating the left auditory area from the right one — an adaptation of later whales that allows directional hearing under water and prevents transmission of sounds through the skull (Gingerich and others 1983). All living whales have foam-filled sinuses along with dense tympanic bullae that create an impedance contrast so they can separate sounds arriving from different directions. There is also no evidence in Pakicetus of vascularization of the middle ear, which is necessary to regulate the pressure within the middle ear during diving (Gingerich and others 1983). Therefore, Pakicetus was probably incapable of achieving dives of any significant depth. This paleontological assessment of the ecological niche of Pakicetus is entirely consistent with the geochemical and paleoenvironmental evidence. When it came to hearing, Pakicetus was more terrestrial than aquatic, but the shape of its skull was definitely cetacean, and its teeth were between the ancestral and modern states.
Ambulocetus
In the same area that Pakicetus was found, but in sediments about 120 meters higher, Thewissen and colleagues (1994) discovered Ambulocetus natans, "the walking whale that swims", in 1992. Dating from the early to middle Eocene, about 50 million years ago, Ambulocetus is a truly amazing fossil. It was clearly a cetacean, but it also had functional legs and a skeleton that still allowed some degree of terrestrial walking. The conclusion that Ambulocetus could walk by using the hind limbs is supported by its having a large, stout femur. However, because the femur did not have the requisite large attachment points for walking muscles, it could not have been a very efficient walker. Probably it could walk only in the way that modern sea lions can walk — by rotating the hind feet forward and waddling along the ground with the assistance of their forefeet and spinal flexion. When walking, its huge front feet must have pointed laterally to a fair degree since, if they had pointed forward, they would have interfered with each other.The forelimbs were also intermediate in both structure and function. The ulna and the radius were strong and capable of carrying the weight of the animal on land. The strong elbow was strong but it was inclined rearward, making possible rearward thrusts of the forearm for swimming. However, the wrists, unlike those of modern whales, were flexible.
It is obvious from the anatomy of the spinal column that Ambulocetus must have swum with its spine swaying up and down, propelled by its back feet, oriented to the rear. As with other aquatic mammals using this method of swimming, the back feet were quite large. Unusually, the toes of the back feet terminated in hooves, thus advertising the ungulate ancestry of the animal. The only tail vertebra found is long, making it likely that the tail was also long. The cervical vertebrae were relatively long, compared to those of modern whales; Ambulocetus must have had a flexible neck.
Ambulocetus's skull was quite cetacean (Novacek 1994). It had a long muzzle, teeth that were very similar to later archaeocetes, a reduced zygomatic arch, and a tympanic bulla (which supports the eardrum) that was poorly attached to the skull. Although Ambulocetus apparently lacked a blowhole, the other skull features qualify Ambulocetus as a cetacean. The post-cranial features are clearly in transitional adaptation to the aquatic environment. Thus Ambulocetus is best described as an amphibious, sea-lion-sized fish-eater that was not yet totally disconnected from the terrestrial life of its ancestors.
Rodhocetus
In the middle Eocene (46-7 million years ago) Rodhocetus took all of these changes even further, yet still retained a number of primitive terrestrial features (Gingerich and others 1994). It is the earliest archaeocete of which all of the thoracic, lumbar, and sacral vertebrae have been preserved. The lumbar vertebrae had higher neural spines than in earlier whales. The size of these extensions on the top of the vertebrae where muscles are attached indicate that Rodhocetus had developed a powerful tail for swimming.Gingrich and others (1994) published this reconstruction of the skeleton of Rodhocetus kasrani (redrawn for RNCSE by Janet Dreyer).
Elsewhere along the spine, the four large sacral vertebrae were unfused. This gave the spine more flexibility and allowed a more powerful thrust while swimming. It is also likely that Rodhocetus had a tail fluke, although such a feature is not preserved in the known fossils: it possessed features — shortened cervical vertebrae, heavy and robust proximal tail vertebrae, and large dorsal spines on the lumbar vertebrae for large tail and other axial muscle attachments — that are associated in modern whales with the development and use of tail flukes. All in all, Rodhocetus must have been a very good tail-swimmer, and it is the earliest fossil whale committed to this manner of swimming.
The pelvis of Rodhocetus was smaller than that of its predecessors, but it was still connected to the sacral vertebrae, meaning that Rodhocetus could still walk on land to some degree. However, the ilium of the pelvis was short compared to that of the mesonychids, making for a less powerful muscular thrust from the hip during walking, and the femur was about 1/3 shorter than Ambulocetus’s, so Rodhocetus probably could not get around as well on land as its predecessors (Gingerich and others 1994).
Rodhocetus's skull was rather large compared to the rest of the skeleton. The premaxillae and dentaries had extended forward even more than its predecessors’, elongating the skull and making it even more cetacean. The molars have higher crowns than in earlier whales and are greatly simplified. The lower molars are higher than they are wide. There is a reduced differentiation among the teeth. For the first time, the nostrils have moved back along the snout and are located above the canine teeth, showing blowhole evolution. The auditory bullae are large and made of dense bone (characteristics unique to cetaceans), but they apparently did not contain the sinuses typical of later whales, making it questionable whether Rodhocetus possessed directional hearing underwater.
Overall, Rodhocetus showed improvements over earlier whales by virtue of its deep, slim thorax, longer head, greater vertebral flexibility, and expanded tail-related musculature. The increase in flexibility and strength in the back and tail with the accompanying decrease in the strength and size of the limbs indicated that it was a good tail-swimmer with a reduced ability to walk on land.
Basilosaurus
The particularly well-known fossil whale Basilosaurus represents the next evolutionary grade in whale evolution (Gingerich 1994). It lived during the late Eocene and latest part of the middle Eocene (35-45 million years ago). Basilosaurus was a long, thin, serpentine animal that was originally thought to have been the remains of a sea serpent (hence it is name, which actually means "king lizard"). Its extreme body length (about 15 meters) appears to be due to a feature unique among whales; its 67 vertebrae are so long compared to other whales of the time and to modern whales that it probably represents a specialization that sets it apart from the lineage that gave rise to modern whales.What makes Basilosaurus a particularly interesting whale, however, is the distinctive anatomy of its hind limbs (Gingerich and others 1990). It had a nearly complete pelvic girdle and set of hindlimb bones. The limbs were too small for effective propulsion, less than 60 cm long on this 15-meter-long animal, and the pelvic girdle was completely isolated from the spine so that weight-bearing was impossible. Reconstructions of the animal have placed its legs external to the body — a configuration that would represent an important intermediate form in whale evolution.
Although no tail fluke has ever been found (since tail flukes contain no bones and are unlikely to fossilize), Gingerich and others (1990) noted that Basilosaurus's vertebral column shares characteristics of whales that do have tail flukes. The tail and cervical vertebrae are shorter than those of the thoracic and lumbar regions, and Gingerich and others (1990) take these vertebral proportions as evidence that Basilosaurus probably also had a tail fluke.
Further evidence that Basilosaurus spent most of its time in the water comes from another important change in the skull. This animal had a large single nostril that had migrated a short distance back to a point corresponding to the back third of the dental array. The movement from the forward extreme of the snout to the a position nearer the top of the head is characteristic of only those mammals that live in marine or aquatic environments.
Dorudon
Dorudon was a contemporary of Basilosaurus in the late Eocene (about 40 million years ago) and probably represents the group most likely to be ancestral to modern whales (Gingerich 1994). Dorudon lacked the elongated vertebrae of Basilosaurus and was much smaller (about 4-5 meters in length). Dorudon’s dentition was similar to Basilosaurus’s; its cranium, compared to the skulls of Basilosaurus and the previous whales, was somewhat vaulted (Kellogg 1936). Dorudon also did not yet have the skull anatomy that indicates the presence of the apparatus necessary for echolocation (Barnes 1984).Gingrich and Uhen (1996) published this reconstruction of the skeleton of Dorudon atrox (redrawn for RNCSE by Janet Dreyer).
Basilosaurus and Dorudon were fully aquatic whales (like Basilosaurus, Dorudon had very small hind limbs that may have projected slightly beyond the body wall). They were no longer tied to the land; in fact, they would not have been able to move around on land at all. Their size and their lack of limbs that could support their weight made them obligate aquatic mammals, a trend that is elaborated and reinforced by subsequent whale taxa.
Clearly, even if we look only at the paleontological evidence, the creationist claim of "No fossil intermediates!" is wrong. In fact, in the case of whales, we have several, beautifully arranged in morphological and chronological order.
In summarizing the paleontological evidence, we have noted the consistent changes that indicate a series of adaptations from more terrestrial to more aquatic environments as we move from the most ancestral to the most recent species. These changes affect the shape of the skull, the shape of the teeth, the position of the nostrils, the size and structure of both the forelimbs and the hindlimbs, the size and shape of the tail, and the structure of the middle ear as it relates to directional hearing underwater and diving. The paleontological evidence records a history of increasing adaptation to life in the water — not just to any way of life in the water, but to life as lived by contemporary whales.
2. Morphological evidence
The examination of the morphological characteristics shared by the fossil whales and living ungulates makes their common ancestry even clearer. For example, the anatomy of the foot of Basilosaurus allies whales with artiodactyls (Gingerich and others 1990). The axis of foot symmetry in these fossil whales falls between the 3rd and 4th digits. This arrangement is called paraxonic and is characteristic of the artiodactyls, whales, and condylarths, and is rarely found in other groups (Wyss 1990).Another example involves the incus (the "anvil" of the middle ear). The incus of Pakicetus, preserved in at least one specimen, is morphologically intermediate in all characters between the incus of modern whales and that of modern artiodactyls (Thewissen and Hussain 1993). Additionally, the joint between the malleus (hammer) and incus of most mammals is oriented at an angle between the middle and the front of the animal (rostromedially), while in modern whales and in ungulates, it is oriented at an angle between the side and the front (rostrolaterally). In Pakicetus, the first fossil cetacean, the joint is oriented rostrally (intermediate in position between the ancestral and derived conditions). Thus the joint has clearly rotated toward the middle from the ancestral condition in terrestrial mammals (Thewissen and Hussain 1993); Pakicetus provides us with a snapshot of the transition.
3. Molecular biological evidence
The hypothesis that whales are descended from terrestrial mammals predicts that living whales and closely related living terrestrial mammals should show similarities in their molecular biology roughly in proportion to the recency of their common ancestor. That is, whales should be more similar in their molecular biology to groups of animals with which they share a more recent common ancestor than to other animals that exhibit convergent similarities in morphology, ecology, or behavior. In contrast, creationism lacks any scientific basis for predicting what the patterns of similarity should be, for there is no scientific way to predict how the creator decided to distribute molecular similarities among species.Molecular studies by Goodman and others (1985) show that whales are more closely related to the ungulates than they are to all other mammals — a result consistent with evolutionary expectations. These studies examined myoglobin, lens alpha-crystallin A, and cytochrome c in a study of 46 different species of mammals. Miyamoto and Goodman (1986) later expanded the number of protein sequences by including alpha- and beta- hemoglobins and ribonuclease; they also increased the number of mammals included in the study to 72. The results were the same: the whales clearly are included among the ungulates. Other molecular studies on a variety of genes, proteins, and enzymes by Irwin and others (1991), Irwin and Arnason (1994), Milinkovitch (1992), Graur and Higgins (1994), Gatesy and others (1996), and Shimamura and others (1997) also identified the whales as closely related to the artiodactyls, although there are differences in the details among the studies.
By placing whales close to, and even firmly within, the Artiodactyls, these molecular studies confirm the predictions made by evolutionary theory. This pattern of biochemical similarities must be present if the whales and the ungulates, especially the Artiodactyls, share a close common ancestor. The fact that these similarities are present is therefore strong evidence for the common ancestry of whales and ungulates.
4. Vestigial evidence
The vestigial features of whales tell us two things. They tell us that whales, like so many other organisms, have features that make no sense from a design perspective — they have no current function, they require energy to produce and maintain, and they may be deleterious to the organism. They also tell us that whales carry a piece of their evolutionary past with them, highlighting a history of a terrestrial ancestry.Modern whales often retain rod-like vestiges of pelvic bones, femora, and tibiae, all embedded within the musculature of their body walls. These bones are more pronounced in earlier species and less pronounced in later species. As the example of Basilosaurus shows, whales of intermediate age have intermediate-sized vestigial pelves and rear limb bones.
Whales also retain a number of vestigial structures in their organs of sensation. Modern whales have only vestigial olfactory nerves. Furthermore, in modern whales the auditory meatus (the exterior opening of the ear canal) is closed. In many, it is merely the size of a thin piece of string, about 1 mm in diameter, and often pinched off about midway. All whales have a number of small muscles devoted to nonexistent external ears, which are apparently a vestige of a time when they were able to move their ears — a behavior typically used by land animals for directional hearing.
The diaphragm in whales is vestigial and has very little muscle. Whales use the outward movement of the ribs to fill their lungs with air. Finally, Gould (1983) reported several occurrences of captured sperm whales with visible, protruding hind limbs. Similarly, dolphins have been spotted with tiny pelvic fins, although they probably were not supported by limb bones as in those rare sperm whales. And some whales, such as belugas, possess rudimentary ear pinnae — a feature that can serve no purpose in an animal with no external ear and that can reduce the animal's swimming efficiency by increasing hydrodynamic drag while swimming.
Although this list is by no means exhaustive, it is nonetheless clear that the whales have a wealth of vestigial features left over from their terrestrial ancestors.
5. Embryological evidence
Like the vestigial features, the embryological features also tells us two things. First, the whale embryo develops a number of features that it later abandons before it attains its final form. How can creationism explain such seemingly nonsensical process, building structures only to abandon them or to destroy them later? Darwin (1859) asked the same question. Would it not make more sense to have embryos attain their adult forms quickly and directly? It seems unreasonable for a perfect designer or creator to send the embryo along such a tortuous pathway, but evolution requires that new features are built on the foundation of previous features that it would modify or discard later.Second, the embryology of the whale, examined in detail, also provides evidence for its terrestrial ancestry. As embryos no less than as adult animals, whales are junkyards, as it were, of old, discarded features that are of no further use to them. Many whales, while still in the womb, begin to develop body hair. Yet no modern whales retain any body hair after birth, except for some snout hairs and hairs around their blowholes used as sensory bristles in a few species. The fact that whales possess the genes for producing body hair shows that their ancestors had body hair. In other words, their ancestors were ordinary mammals.
In many embryonic whales, external hind limb buds are visible for a time but thendisappear as the whale grows larger. Also visible in the embryo are rudimentary ear pinnae, which disappear before birth (except in those that carry them as rare atavisms). And, in some whales, the olfactory lobes of the brain exist only in the fetus. The whale embryo starts off with its nostrils in the usual place for mammals, at the tip of the snout. But during development, the nostrils migrate to their final place at the top of the head to form the blowhole (or blowholes).
We can also understand evolution within the whales via their embryology. We know that the baleen whales evolved from the toothed whales: some embryos of the baleen whales begin to develop teeth. As with body hair, the teeth disappear before birth. Since there is no use for teeth in the womb, only inheritance from a common ancestor makes any sense; there is no reason for the intelligent designer or special creator to provide embryonic whales with teeth. So we have yet another independent field in complete accord with the overall thesis — that whales possess features that connect them with terrestrial mammalian ancestors, in particular the hoofed mammals.
6. Geochemical evidence
The earliest whales lived in freshwater habitats, but the ancestors of modern whales moved into saltwater habitats and thus had to adapt to drinking salt water. Since fresh water and salt water have somewhat different isotopic ratios of oxygen, we can predict that the transition will be recorded in the whales' skeletal remains — the most enduring of which are the teeth. Sure enough, fossil teeth from the earliest whales have lower ratios of heavy oxygen to light oxygen, indicating that the animals drank fresh water (Thewissen and others 1996). Later fossil whale teeth have higher ratios of heavy oxygen to light oxygen, indicating that they drank salt water. This absolutely reinforces the inference drawn from all the other evidence discussed here: the ancestors of modern whales adapted from terrestrial habitats to saltwater habitats by way of freshwater habitats.7. Paleoenvironmental evidence
Evolution makes other predictions about the history of taxa based on the "big-picture" view of the fossils in a larger, environmental, context. The sequence of whale fossils and their changes should also relate to changes observed in the fossil records of other organisms at the same time and in similar environments. The fossils of other organisms associated with the whale fossils indicate the environment that the whales lived in. Furthermore, this evidence should be consistent with the evidence from the other areas of study. We should expect to find evidence for a series of transitional environments, from fully terrestrial to fully marine, occupied by the series of whale species in the fossil record.The morphology of Sinonyx indicates that it was fully terrestrial. It should be no surprise, therefore, that its fossils are found associated with the fossils of other terrestrial animals. Pakicetus probably spent a lot of time in the water in search of food. Although the mammalian fauna found with Pakicetus consists of rodents, bats, various artiodactyls, perissodactyls and probiscideans, and even a primate (Gingerich and others 1983), there are also aquatic animals such as snails, fish, turtles and crocodilians. Moreover, the sediment associated with Pakicetus shows evidence of streaming or flowing, usually associated with soils that are carried by water. The paleoenvironmental evidence thus clearly shows that Pakicetus lived in the low-lying wet terrestrial environment, making occasional excursions into fresh water. Interestingly, both deciduous and permanent teeth of the animal are found in these sediments with about the same frequency, supporting the idea that Pakicetus gave birth on the land.
The sediments in which Ambulocetus was found contain leaf impressions as well as fossils of the turret-snail Turritella and other marine mollusks. Clearly, the presence of such fossils must mean that the Ambulocetus fossil was found in what was once a shallow sea — although leaves can be washed into the sea and fossilize there, marine mollusks would not be found on the land.
Rodhocetus is found in green shales deposited in the deep-neritic zone (equivalent to the outer part of the continental shelf). Because green shales are associated with fairly low-oxygen bottom waters, Rodhocetus must have lived at a greater water depth than any previous cetacean. The fact that it is found in association with planktonic foraminiferans and other microfossils agrees with this determination of water depth. Basilosaurus and Dorudon have been found in a variety of sediment types (Kellogg 1936), indicating that they were wide-ranging and capable of living in deep as well as shallow water.
From the paleoenvironmental evidence, we can clearly see that, as whales evolved, they made their way into deeper water and became progressively liberated from the terrestrial and near-shore environments.
8. Paleobiogeographic evidence
The geographic evidence is also consistent with the expected distributional patterns for the whale’s first appearance and later geographic expansion. We would expect terrestrial species to have a more restricted geographic distribution than marine species, which have essentially the whole ocean as their geographic range. The range of Sinonyx is restricted to central Asia. Specimens of Pakicetus have only been found in Pakistan; Ambulocetus and Rodhocetus seem to be similarly restricted. In contrast, Basilosaurus and Dorudon, representing the whales more adapted to living in the open sea, are found in a much wider area. Their fossils have been found as far away from southern Asia as Georgia, Louisiana, and British Columbia.During the Eocene, most of the areas in which fossils of the later whales have been found were fairly close to one another. In fact, most of them are along the outer margin of an ancient sea called the Tethys, the remnants of which today are the Mediterranean, the Caspian, the Black, and the Aral Seas. The biogeographic distribution of fossil whales matches the pattern predicted by evolution: whales are initially found in a rather small geographic area and did not become distributed throughout the world until after they evolved into fully aquatic animals that were no longer tied to the land.
9. Chronological evidence
The final strand of evidence in our mutually consistent picture of whale origins comes from a consideration of why the whales originated when they did. Evolution is a response to environmental challenges and opportunities. During the early Cenozoic, mammals were presented with a new set of opportunities for radiation and diversification due, in part, to the vacuum left by mass extinctions at the close of the Cretaceous Period. Because the reptiles no longer predominated, there were new ways in which mammals could make a living.In the specific case of whales, the swimming reptiles of the world's oceans could no longer keep the mammals at bay. Before the late-Cretaceous extinctions, the Mesozoic marine reptiles such as the plesiosaurs, ichthyosaurs, mosasaurs, and marine crocodiles might well have feasted upon any mammal that strayed off shore in search of food. Once those predators were gone, the evolution quickly produced mammals, including whales, that were as at home in the seas as they once were on land. The transition took some 10-15 million years to produce fully aquatic, deep-diving whales with directional underwater hearing. Evolution predicts that whales could not have successfully appeared and radiated before the Eocene, and that mammals should have radiated into marine environments as they did into a wide variety of other environments vacated by the reptiles at the end of the Cretaceous.
Conclusion
Taken together, all of this evidence points to only one conclusion — that whales evolved from terrestrial mammals. We have seen that there are nine independent areas of study that provide evidence that whales share a common ancestor with hoofed mammals. The power of evidence from independent areas of study that support the same conclusion makes refutation by special creation scenarios, personal incredulity, the argument from ignorance, or "intelligent design" scenarious entirely unreasonable. The only plausible scientific conclusion is that whales did evolve from terrestrial mammals. So no matter how much anti-evolutionists rant about how impossible it is for land-dwelling, furry mammals to evolve into fully aquatic whales, the evidence itself shouts them down. This is the power of using mutually reinforcing, independent lines of evidence. I hope that it will become a major weapon to strike down groundless anti-evolutionist objections and to support evolutionary thinking in the general public. This is how real science works, and we must emphasize the process of scientific inference as we point out the conclusions that scientists draw from the evidence — that the concordant predictions from independent fields of scientific study confirm the same pattern of whale ancestry.Acknowledgements
I would like to thank Dr Philip Gingerich for his assistance with and review of this article.References
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Gatesy J, Hayashi C, Cronin MA, Arctander P. Evidence from milk casein genes that cetaceans are close relatives of hippopotamid artiodactyls. Molecular Biology and Evolution 1996; 13 (7): 954-63.
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Gingerich P, Raza SM, Arif M, Anwar M, Zhou X. New whale from the Eocene of Pakistan and the origin of cetacean swimming. Nature 1994; 368: 844-7.
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Gingerich P, Wells NA, Russell DE, Shah SMI. Origin of whales in epicontinental remnant seas: new evidence from the early Eocene of Pakistan, Science 1983; 220: 403-6.
Gish DT. Evolution: The Challenge of the Fossil Record. El Cajon (CA): Creation-Life Publishers, 1985.
Goodman M, Czelusniak J, Beeber J. Phylogeny of primates and other eutherian orders: a cladistic analysis using amino acid and nucleotide sequence data. Cladistics 1985; 1 (2): 171-85.
Gould SJ. Hen's teeth and horse's toes. In: Hen's Teeth and Horse's Toes. Norton: New York, 1983. p 177-86.
Gould SJ. Hooking leviathan by its past. In: Dinosaur in a Haystack, New York: Harmony Books, 1995. p 359-76.
Graur D, Higgins DG. Molecular evidence for the inclusion of cetaceans within the order Artiodactyla. Molecular Biology and Evolution 1994; 11 (3): 357-64.
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Irwin DM, Kochner TD, Wilson AC. Evolution of the cytochrome b gene of mammals. Journal of Molecular Evolution 1991; 32: 128-44.
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RNCSE 20 (6)
Articles available online are listed below.
Senseless in the Senate
Originally published in RNCSE 20 (6): 4. The version on the web might differ slightly from the print publication.
On June 13, 2001, the US Senate adopted a “Sense of the Senate” resolution, proposed by Senator Rick Santorum (R-Pennsylvania), as part of the Elementary and Secondary Education Act Authorization bill, S1, currently under consideration. The resolution (Amendment #799) reads:
The fact that evolution is singled out from all controversial issues indicates the amendment’s intention to discourage evolution education. It is no coincidence that Senator Santorum cited arguments for “teaching the controversy” made by intelligent design proponent David DeWolf in presenting his resolution. In the June 18 Washington Times, another intelligent design promoter, Phillip Johnson, is quoted as having “helped frame the language” of the resolution.
The vote to adopt the resolution was 91–8. It seems likely that most or nearly all senators were unaware of the anti-evolution implications of the language of the amendment. However, the tactic of singling out evolution for special mention as controversial is commonly used by anti-evolutionists in states and localities where they challenge its place in science education.
The comments of several senators in the Congressional Record suggest that they recognized the implications of the resolution. Senator Sam Brownback of Kansas stated that passage of this resolution would justify the 1999 actions of the Kansas State Board of Education in removing evolution from their test standards. Senator Robert Byrd of West Virginia also expressed doubts about the reality of evolution before supporting the amendment.
The comments of anti-evolution groups following passage of the resolution also show the propaganda value they recognize in this language. The Answers in Genesis ministry web site headlined its account “US Senate supports intellectual freedom!”. AIG also informed its readers how to “… contact your Congressman to express your support of the Senate version of the Education bill that states that evolution is controversial…” A student “intelligent design” club at the University of California at San Diego headlined its report “Some Democratic and Republican Senators Feel Questioning of Evolutionary Theory in Schools is Legitimate”.
On June 14, the overall bill passed the Senate 91–8. The House of Representatives had previously passed a version of the Education bill without a comparable evolution statement. The two versions are currently before a conference committee, which will resume work on reconciling the bills following Congress’s August recess.
Other accounts of the Santorum amendment are available on the American Geological Institute’s web site or visit here.
On June 13, 2001, the US Senate adopted a “Sense of the Senate” resolution, proposed by Senator Rick Santorum (R-Pennsylvania), as part of the Elementary and Secondary Education Act Authorization bill, S1, currently under consideration. The resolution (Amendment #799) reads:
It is the sense of the Senate that (1) good science education should prepare students to distinguish the data or testable theories of science from philosophical or religious claims that are made in the name of science; and (2) where biological evolution is taught, the curriculum should help students to understand why the subject generates so much continuing controversy, and should prepare the students to be informed participants in public discussions regarding the subject.Although the resolution appears innocuous, it is telling that only evolution is singled out from all possible controversial issues. If the goal of the resolution were simply to encourage discussion of the social dimensions of scientific issues, or critical thinking, or some other secular purpose, the second clause of the resolution might have read, “when controversial issues are taught, the curriculum should help students to understand why the subjects generate controversy, and should prepare the students to be informed participants in public discussions regarding the subjects.”
The fact that evolution is singled out from all controversial issues indicates the amendment’s intention to discourage evolution education. It is no coincidence that Senator Santorum cited arguments for “teaching the controversy” made by intelligent design proponent David DeWolf in presenting his resolution. In the June 18 Washington Times, another intelligent design promoter, Phillip Johnson, is quoted as having “helped frame the language” of the resolution.
The vote to adopt the resolution was 91–8. It seems likely that most or nearly all senators were unaware of the anti-evolution implications of the language of the amendment. However, the tactic of singling out evolution for special mention as controversial is commonly used by anti-evolutionists in states and localities where they challenge its place in science education.
The comments of several senators in the Congressional Record suggest that they recognized the implications of the resolution. Senator Sam Brownback of Kansas stated that passage of this resolution would justify the 1999 actions of the Kansas State Board of Education in removing evolution from their test standards. Senator Robert Byrd of West Virginia also expressed doubts about the reality of evolution before supporting the amendment.
The comments of anti-evolution groups following passage of the resolution also show the propaganda value they recognize in this language. The Answers in Genesis ministry web site headlined its account “US Senate supports intellectual freedom!”. AIG also informed its readers how to “… contact your Congressman to express your support of the Senate version of the Education bill that states that evolution is controversial…” A student “intelligent design” club at the University of California at San Diego headlined its report “Some Democratic and Republican Senators Feel Questioning of Evolutionary Theory in Schools is Legitimate”.
On June 14, the overall bill passed the Senate 91–8. The House of Representatives had previously passed a version of the Education bill without a comparable evolution statement. The two versions are currently before a conference committee, which will resume work on reconciling the bills following Congress’s August recess.
Other accounts of the Santorum amendment are available on the American Geological Institute’s web site or visit here.
Anti-evolution Standards Rejected in Hawai'i
On August 2, 2001, the Hawai'i Board of Education (BOE) voted unanimously to reject proposed changes to the state's science education performance standards, including the changes proposed by BOE member Denise Matsumoto to include "multiple theories of origin" and related wording. As a result, the standards will revert to the original wording, which is more in line with the National Science Education Standards. The BOE members patiently endured 65 three-minute oral testimonials on these changes; about 75% of the presenters opposed the proposed changes. Apparently, this was a record turnout for a BOE hearing. Additionally, the BOE had received over 200 written testimonials.
Testimony opposing the proposed changes came from a wide spectrum of people, including university-level professors, Hawai'i science teachers, concerned citizens, a former BOE member, and a surprising (and encouraging!) number of religious leaders. Almost without exception, this testimony was eloquent and extremely effective in addressing the real points of concern. Those testifying in favor of the proposed changes had a much less unified message to present, covering the typical range of anti-evolutionary positions — attacks on evolution as unsupported conjecture, appeals for children to be given both perspectives and allowed to think critically and objectively to make their own decisions, support of "Intelligent Design" theory as legitimate science, and the moral imperative of teaching the Bible to build character and integrity in our children.
Overall, the testimony provided by supporters of evolution was effective and to the point. Long before the end of hearing, it was evident that this would end up being a "slam dunk" decision by the BOE. There was almost no discussion among board members before making the final, and the final vote was unanimous — making it obvious that even Matsumoto conceded the issue. This outcome confirms resoundingly that community support can help level heads to prevail. In light of this success story, I think that we can renew our confidence in the Hawai'i State Educational system. However, it is clear that we should not allow ourselves to slip into complacency at this point. We were extremely lucky that Matsumoto apparently blundered into the situation with such a naive perspective. Our success was due in part to the disorganization of the opposing side. Had this hearing been coordinated by some of the big anti-evolutionist organizations on the mainland, it might have been a longer, more complicated struggle. What our experience shows is the importance of having a network of concerned and informed citizens ready to act when evolution education is threatened. It is also important that our network reaches beyond the academic world to other interested communities of educators, clergy, and citizens in all walks of life.
Organizations such as NCSE and the American Institute for Biological Sciences (see sidebar on AIBS state list servers, p 35) provide resources and connections to concerned communities throughout the nation. These networks allow us to be ready whenever a threat to evolution education pops up again (as experience tells us it will) and to coordinate efforts with maximum effectiveness.
Review: The Wedge of Truth
Paul Tillich, the great German and American theologian, warned theologians never to embrace or reject any scientific idea for purely theological reasons. Such a strategy is theologically injudicious not only because scientific ideas are always subject to revision but also because new ideas from science can be an important stimulus to theological development.
One such idea has been that of evolution. Followers of Tillich's dictum do not reject or edit Darwin's "dangerous idea" if at first it seems not to sit well with certain inherited theological ideas. Instead they embrace it in all of its raggedness and, if need be, modify their theology accordingly. Although skeptics might consider such theological revision a defeat for religion, the fact is that religious thought has often undergone important change in the face of new intellectual challenges. Otherwise it might have died.
Phillip Johnson, however, wants nothing to do with theological revision. A (now-retired) University of California-Berkeley law professor and not a professional theologian, Johnson has written another in a series of books and articles drumming home his opinion that evolutionary science is simply theologically unacceptable. He already knows exactly what he wants in his vision of the universe, and evolutionary science's picture of life does not fit the bill. Unlike Tillich, who refused to allow theology to dictate to science, Johnson has made a second career of telling his readers what to think about evolutionary biology. In each new publication, his message to them is the same: if they want anything to do with God, they must renounce the central tenets of evolutionary biology.
Johnson's anti-evolutionary argument has itself undergone no significant evolution since he wrote Darwin on Trial (Washington DC: Regnery Gateway, 1991). We can always safely predict the contours of his impeccable logic:
In The Wedge of Truth Johnson does not disappoint us. As always, he is readable, interesting, and often clever. But after making our way through this thin volume, we find that the old familiar refrain sounds through once again: The ruling philosophy of modern culture is naturalism, materialism, or physicalism, and evolutionary science is the main carrier of this dour metaphysics. We find here yet again Johnson's firm refusal to accept the distinction that most religious thinkers and scientists make between methodological and philosophical naturalism. To Johnson it seems that if evolutionary science leaves out God as part of its method, this will likely lead scientifically educated people to leave out God in their extrascientific interpretations of the world as well. While most of us are willing to let science refrain from any comments on value, purpose, and the existence of God, Johnson is not. Here again he takes evolutionary biology's silence about things religious to be an outright denial of God's existence.
What is fresh in this book is some of the imagery in Johnson's otherwise predictable message. The "Wedge" of truth will split the "modern" naturalistic synthesis asunder. Its cutting edge consists of the brave (and academically marginalized) defenders of "Intelligent Design", especially William Dembski, Michael Behe, and Johnson himself. Inserted into "the log of naturalism" and hammered home by Johnson's logic, the Wedge — in combination with the cultural influence of evangelical Christianity — will breach the palisade of scientific naturalism and expose the infectious evolutionary ideas that are its main carrier.
The fissure at which the Wedge penetrates the log of materialism is Darwin's science. Once the Wedge has splayed open evolution as nothing more than a decaying veneer of bark that conceals the trunk of atheist propaganda, Darwinism will begin to lose its hold on the minds of people, including teachers and students. Maybe the next generation of Americans will have begun to get things right once again, and science textbooks will have been purged of the idea that new species of life can gradually evolve by natural selection over the course of time from a common ancestry.
Since I am one of the evolution-friendly theologians The Wedge brands as "modernist" compromisers of truth, Johnson will not be surprised that I would find fault lines in his own unchanging position on evolution, science, and theology. These are really not hard to locate.
First of all, there is Johnson's highly edited version of biology as ruling out macroevolution (he accepts "microevolution" but claims that it cannot lead to whole new biological types). In rebuttal, there is no need here to reprise the scientific information on evolution that most readers of RNCSE have at their fingertips. From my own point of view, though, what is particularly striking is Johnson's violation of the now well-established principle that theology has no business dictating what the range of data for scientific understanding will include. Without admitting it, Johnson, the would-be theologian, is telling scientists to avoid any data that do not fit the Wedge's idea of "Intelligent Design". In effect, this means that he — along with Dembski, Behe, and others — is asking biologists to leave out most of the fascinating story of life on earth.
Second, there is Johnson's unwavering insistence that the evolutionary idea of natural selection is inherently atheistic. While it is no doubt true that some scientific defenders of Darwinism do read natural selection through the lenses of philosophical materialism, the scientific idea itself cannot be any more inherently atheistic than is the law of gravity or any other law of nature. If some scientists see atheism as a consequence of evolutionary science, then they are no less guilty of violating the canons of scientific method than is Phillip Johnson, who fully concurs with them in this belief. They are implicitly lending their scientific authority to the minor premise of Johnson's syllogism. In doing so, they themselves unwittingly sabotage science education in an overwhelmingly theistic social setting.
If the evolutionist, in a pensive moment, opines that a universe sponsoring such a "cruel" or "impersonal" process as natural selection must surely be a godless one, let it be admitted that such reflection is not itself part of scientific work. Science does not admit of such metaphysical intrusions. If there is any value in Johnson's work, perhaps it consists in its oblique rebuke to those scientists who recklessly engage in a mixing of science with materialist ideology and then call this amalgam "science". Such a fusion, after all, is no less methodologically inadmissible than Johnson's own conflation of a heavily edited version of biological science with the incurably theological notion of "Intelligent Design".
Third, there is Johnson's theologically disputable squeezing of the idea of God into the mold of "Intelligent Design". To Johnson's credit, he does turn our attention to an issue that deserves serious attention, namely the meaning of "information" and its place in nature. Yet he tends to merge the notion of information with his own rather restrictive idea of design, and then attributes its presence directly to divine influence.
Johnson and other "Intelligent Design" advocates are too eager to bring God into the picture. A God brought in so hastily, however, is inevitably too small for both our minds and our spirits, and will eventually die. The best of our religious wisdom, after all, tells us that God is a reality for which we must somehow wait, perhaps across endless ages. Moreover, as Tillich also wisely says, we are stronger when we wait than when we possess. A God hastily associated with "design" as Johnson conceives of it is too easily possessed, too small to fit the real world, and may not be worth waiting for.
One such idea has been that of evolution. Followers of Tillich's dictum do not reject or edit Darwin's "dangerous idea" if at first it seems not to sit well with certain inherited theological ideas. Instead they embrace it in all of its raggedness and, if need be, modify their theology accordingly. Although skeptics might consider such theological revision a defeat for religion, the fact is that religious thought has often undergone important change in the face of new intellectual challenges. Otherwise it might have died.
Phillip Johnson, however, wants nothing to do with theological revision. A (now-retired) University of California-Berkeley law professor and not a professional theologian, Johnson has written another in a series of books and articles drumming home his opinion that evolutionary science is simply theologically unacceptable. He already knows exactly what he wants in his vision of the universe, and evolutionary science's picture of life does not fit the bill. Unlike Tillich, who refused to allow theology to dictate to science, Johnson has made a second career of telling his readers what to think about evolutionary biology. In each new publication, his message to them is the same: if they want anything to do with God, they must renounce the central tenets of evolutionary biology.
Johnson's anti-evolutionary argument has itself undergone no significant evolution since he wrote Darwin on Trial (Washington DC: Regnery Gateway, 1991). We can always safely predict the contours of his impeccable logic:
Major premise:
Philosophical naturalism is atheism.Minor premise:
Evolutionary science is philosophical naturalism.Conclusion:
Therefore, evolutionary science is really atheism.In The Wedge of Truth Johnson does not disappoint us. As always, he is readable, interesting, and often clever. But after making our way through this thin volume, we find that the old familiar refrain sounds through once again: The ruling philosophy of modern culture is naturalism, materialism, or physicalism, and evolutionary science is the main carrier of this dour metaphysics. We find here yet again Johnson's firm refusal to accept the distinction that most religious thinkers and scientists make between methodological and philosophical naturalism. To Johnson it seems that if evolutionary science leaves out God as part of its method, this will likely lead scientifically educated people to leave out God in their extrascientific interpretations of the world as well. While most of us are willing to let science refrain from any comments on value, purpose, and the existence of God, Johnson is not. Here again he takes evolutionary biology's silence about things religious to be an outright denial of God's existence.
What is fresh in this book is some of the imagery in Johnson's otherwise predictable message. The "Wedge" of truth will split the "modern" naturalistic synthesis asunder. Its cutting edge consists of the brave (and academically marginalized) defenders of "Intelligent Design", especially William Dembski, Michael Behe, and Johnson himself. Inserted into "the log of naturalism" and hammered home by Johnson's logic, the Wedge — in combination with the cultural influence of evangelical Christianity — will breach the palisade of scientific naturalism and expose the infectious evolutionary ideas that are its main carrier.
The fissure at which the Wedge penetrates the log of materialism is Darwin's science. Once the Wedge has splayed open evolution as nothing more than a decaying veneer of bark that conceals the trunk of atheist propaganda, Darwinism will begin to lose its hold on the minds of people, including teachers and students. Maybe the next generation of Americans will have begun to get things right once again, and science textbooks will have been purged of the idea that new species of life can gradually evolve by natural selection over the course of time from a common ancestry.
Since I am one of the evolution-friendly theologians The Wedge brands as "modernist" compromisers of truth, Johnson will not be surprised that I would find fault lines in his own unchanging position on evolution, science, and theology. These are really not hard to locate.
First of all, there is Johnson's highly edited version of biology as ruling out macroevolution (he accepts "microevolution" but claims that it cannot lead to whole new biological types). In rebuttal, there is no need here to reprise the scientific information on evolution that most readers of RNCSE have at their fingertips. From my own point of view, though, what is particularly striking is Johnson's violation of the now well-established principle that theology has no business dictating what the range of data for scientific understanding will include. Without admitting it, Johnson, the would-be theologian, is telling scientists to avoid any data that do not fit the Wedge's idea of "Intelligent Design". In effect, this means that he — along with Dembski, Behe, and others — is asking biologists to leave out most of the fascinating story of life on earth.
Second, there is Johnson's unwavering insistence that the evolutionary idea of natural selection is inherently atheistic. While it is no doubt true that some scientific defenders of Darwinism do read natural selection through the lenses of philosophical materialism, the scientific idea itself cannot be any more inherently atheistic than is the law of gravity or any other law of nature. If some scientists see atheism as a consequence of evolutionary science, then they are no less guilty of violating the canons of scientific method than is Phillip Johnson, who fully concurs with them in this belief. They are implicitly lending their scientific authority to the minor premise of Johnson's syllogism. In doing so, they themselves unwittingly sabotage science education in an overwhelmingly theistic social setting.
If the evolutionist, in a pensive moment, opines that a universe sponsoring such a "cruel" or "impersonal" process as natural selection must surely be a godless one, let it be admitted that such reflection is not itself part of scientific work. Science does not admit of such metaphysical intrusions. If there is any value in Johnson's work, perhaps it consists in its oblique rebuke to those scientists who recklessly engage in a mixing of science with materialist ideology and then call this amalgam "science". Such a fusion, after all, is no less methodologically inadmissible than Johnson's own conflation of a heavily edited version of biological science with the incurably theological notion of "Intelligent Design".
Third, there is Johnson's theologically disputable squeezing of the idea of God into the mold of "Intelligent Design". To Johnson's credit, he does turn our attention to an issue that deserves serious attention, namely the meaning of "information" and its place in nature. Yet he tends to merge the notion of information with his own rather restrictive idea of design, and then attributes its presence directly to divine influence.
Johnson and other "Intelligent Design" advocates are too eager to bring God into the picture. A God brought in so hastily, however, is inevitably too small for both our minds and our spirits, and will eventually die. The best of our religious wisdom, after all, tells us that God is a reality for which we must somehow wait, perhaps across endless ages. Moreover, as Tillich also wisely says, we are stronger when we wait than when we possess. A God hastily associated with "design" as Johnson conceives of it is too easily possessed, too small to fit the real world, and may not be worth waiting for.
Review: Science of Today and the Problems of Genesis
If there is any book that was really pivotal in laying "creation science" before the public, it is surely Duane Gish's Evolution: The Fossils Say No!, first published in 1972. Among other tidbits in this book, there is a 13-page exposé in which Gish purports to demolish the claims for the very existence of "Peking Man", arguing that the conclusions supporting this human fossil are based on not merely bad science, but fraud. The charge of bad science"he substantiates by famously misquoting the early 20th-century paleoanthropologist Marcellin Boule (see Ritchie 1991); for his claims of fraud he relies, in the last four and a half pages of the section, on a 1969 book by Father Patrick O'Connell. O'Connell's book has been a bit hard to come by up to now; most of us have just had to take Gish's word for it. But now here it is, reprinted and slightly updated as of 1993, available through Amazon.com. Now we can check: Did Gish misrepresent O'Connell, or did a priest, a man devoted to the truth, really say all that?
He really did say all that, I fear, and more. Gish mentions O'Connell only in those last few pages, but actually relies heavily on him for the whole of the "Peking Man" segment, and for his "Java Man" section, too. Every last libel on anyone involved with Homo erectus, every shabby slur on the reputation of these honorable men, is lifted entire, attributed or unattributed, from O'Connell.
O'Connell's book is divided into four parts. In Part I, "The Six Days of Creation", he quotes extensively from Vatican documents, including the Decree of the Second Vatican Council, on what may and may not be believed by a Roman Catholic. O'Connell recounts the history of creation as he sees it and squares it with the Genesis account (he is a day/age man). Part II, "The Origin of Man", is the meat of the book, and I will return to it for a detailed treatment below. Part III deals with the Deluge, which, we learn, intervened between the end of the Mousterian and the beginning of the Aurignacian cultures and did not cover the entire earth but only those parts of it then inhabited by people. O'Connell cites lots of archaeological "evidences" for the Deluge (well, for floods, anyway) from the Middle East and elsewhere. Part IV, "The Antiquity of Man", runs quickly through ways of calculating dates, including radiocarbon but no other radiometric method, and concludes that the human species is about 20 000 years old. There are chapters that are supposed to bring Parts I, III, and IV up to date — but there is no such updating for Part II.
And so to "The Origin of Man" part — the bit that has created all the waves. O'Connell bemoans the way Roman Catholics, both ordained and lay, have not only accepted the evolutionary account but even, like the Abbé Breuil and Fr Boné, contributed to it. His chief wrath, however, is directed towards Fr Pierre Teilhard de Chardin, the eminent paleontologist who was also a Jesuit, and was forbidden by his superiors to publish during his lifetime his views reconciling evolution with paleontology. Wrath? O'Connell vehemently detests Teilhard, and his assessment of his brother priest, on pages 149–54, is filled with such venom as I would have hoped never to see on the printed page, let alone from a man charged with spreading the religion of brotherly love.
Minor matters are dispatched in a few pages. O'Connell informs us that "Neanderthal Man" was, of course, fully human but not like modern humans, being pre-Deluge. The human fossils that O'Connell regards as genuine either combine Neanderthal and modern traits (Ehringsdorf, Saccopastore, Steinheim) or are fully modern (Swanscombe and Fontéchevade). The obligatory chapter on Piltdown is mercifully brief. The Australopithecines were, he says, "shown to be just great apes"; that takes care of them, then. O'Connell kicks off a great and inglorious tradition by citing none other than Sir Solly Zuckerman as authority. So now we turn to Peking Man.
What actually happened at the "Peking Man" discovery site, Choukoutien (now Zhoukoudian), has been told many times. Jia and Huang (1990) give the full history in great detail. Shapiro (1974) writes about their disappearance during World War II and the subsequent search for them. Van Oosterzee (1999) places the story against the background of China under the warlords and the Japanese invasion. But O'Connell thinks that this well-documented history is all moonshine and is eager to take the lid off what really happened.
Although "Peking Man" — Sinanthropus — may or may not be actually ancestral to Homo sapiens (and I myself think not), there is absolutely no doubt that it is in every meaningful sense "intermediate" between ape and human. It was vital for O'Connell to discredit the fossils because they are "the only ones that have the support of great names. Hence they are used by advocates of the theory of evolution to support their contention." And he certainly does his level best to discredit them, in the process accusing all four main protagonists of fraud: Teilhard de Chardin (of course); Davidson Black, who was in charge of the excavations at Zhoukoudian until his death in 1934; Franz Weidenreich, who took his place; and Pei Wen-chung (now spelled Wenzhong), the leading Chinese member of the team.
O'Connell's qualifications for his claims? Only that he was in China, reading the Chinese newspapers, during the 1930s. He never, at any time, visited the discovery site, nor, as will become clear, does he have the slightest expertise in anatomy, geology, or even etymology. Gish repeated a few of O'Connell's claims of fraudulence, but even he does not stoop quite to the same depths; O'Connell's only rival in libel is another Catholic creationist, who repeats the claims in only slightly abbreviated form, even adding his own commentary about Pei's diabolical cleverness (Johnson 1982).
I will list O'Connell's main slanders, more or less in order, and follow each one with my own comments, in italics.
What do we make of O'Connell? His motives are evident: an old-fashioned Catholic, desperately struggling against the modernizers whose efforts to bring the church, kicking and screaming, into the Enlightenment — no, into the Renaissance — finally began to bear fruit in Vatican II. Like some other traditionalists, and even some not-so-traditionalists (see Scharle 1999), he harbors a deep well of hatred against his opponents (witness his unedifying attacks on the reputation of Teilhard de Chardin). Because he has right on his side, he can destroy the reputations of those who incur his detestation without a second thought: fortunate for him, perhaps, that by the time of his first edition all his targets were either dead or, in the case of Pei, alive but isolated from outside contact in Mao's China. He is aided in his crusade by his astonishing invention of whole new scenarios, his willful disdain for actually reading the books and papers that he disparages, his triumphant ignorance of anatomy — he does not even know what the words mean, and quite obviously he does not want to know.
It says a lot about Gish that he takes this poisonous garbage as his primary, no, his only source on "Peking Man" and "Java Man" — that he is willing to lower himself to the level of this unspeakable nastiness. And let us, perhaps, raise at least one, whispered cheer for Marvin Lubenow who has managed to avoid it — although he must surely know about it, he never endorses it. But he and others of his sort might merit some respect from us, their critics, if they joined forthrightly in its condemnation.
He really did say all that, I fear, and more. Gish mentions O'Connell only in those last few pages, but actually relies heavily on him for the whole of the "Peking Man" segment, and for his "Java Man" section, too. Every last libel on anyone involved with Homo erectus, every shabby slur on the reputation of these honorable men, is lifted entire, attributed or unattributed, from O'Connell.
O'Connell's book is divided into four parts. In Part I, "The Six Days of Creation", he quotes extensively from Vatican documents, including the Decree of the Second Vatican Council, on what may and may not be believed by a Roman Catholic. O'Connell recounts the history of creation as he sees it and squares it with the Genesis account (he is a day/age man). Part II, "The Origin of Man", is the meat of the book, and I will return to it for a detailed treatment below. Part III deals with the Deluge, which, we learn, intervened between the end of the Mousterian and the beginning of the Aurignacian cultures and did not cover the entire earth but only those parts of it then inhabited by people. O'Connell cites lots of archaeological "evidences" for the Deluge (well, for floods, anyway) from the Middle East and elsewhere. Part IV, "The Antiquity of Man", runs quickly through ways of calculating dates, including radiocarbon but no other radiometric method, and concludes that the human species is about 20 000 years old. There are chapters that are supposed to bring Parts I, III, and IV up to date — but there is no such updating for Part II.
And so to "The Origin of Man" part — the bit that has created all the waves. O'Connell bemoans the way Roman Catholics, both ordained and lay, have not only accepted the evolutionary account but even, like the Abbé Breuil and Fr Boné, contributed to it. His chief wrath, however, is directed towards Fr Pierre Teilhard de Chardin, the eminent paleontologist who was also a Jesuit, and was forbidden by his superiors to publish during his lifetime his views reconciling evolution with paleontology. Wrath? O'Connell vehemently detests Teilhard, and his assessment of his brother priest, on pages 149–54, is filled with such venom as I would have hoped never to see on the printed page, let alone from a man charged with spreading the religion of brotherly love.
Minor matters are dispatched in a few pages. O'Connell informs us that "Neanderthal Man" was, of course, fully human but not like modern humans, being pre-Deluge. The human fossils that O'Connell regards as genuine either combine Neanderthal and modern traits (Ehringsdorf, Saccopastore, Steinheim) or are fully modern (Swanscombe and Fontéchevade). The obligatory chapter on Piltdown is mercifully brief. The Australopithecines were, he says, "shown to be just great apes"; that takes care of them, then. O'Connell kicks off a great and inglorious tradition by citing none other than Sir Solly Zuckerman as authority. So now we turn to Peking Man.
What actually happened at the "Peking Man" discovery site, Choukoutien (now Zhoukoudian), has been told many times. Jia and Huang (1990) give the full history in great detail. Shapiro (1974) writes about their disappearance during World War II and the subsequent search for them. Van Oosterzee (1999) places the story against the background of China under the warlords and the Japanese invasion. But O'Connell thinks that this well-documented history is all moonshine and is eager to take the lid off what really happened.
Although "Peking Man" — Sinanthropus — may or may not be actually ancestral to Homo sapiens (and I myself think not), there is absolutely no doubt that it is in every meaningful sense "intermediate" between ape and human. It was vital for O'Connell to discredit the fossils because they are "the only ones that have the support of great names. Hence they are used by advocates of the theory of evolution to support their contention." And he certainly does his level best to discredit them, in the process accusing all four main protagonists of fraud: Teilhard de Chardin (of course); Davidson Black, who was in charge of the excavations at Zhoukoudian until his death in 1934; Franz Weidenreich, who took his place; and Pei Wen-chung (now spelled Wenzhong), the leading Chinese member of the team.
O'Connell's qualifications for his claims? Only that he was in China, reading the Chinese newspapers, during the 1930s. He never, at any time, visited the discovery site, nor, as will become clear, does he have the slightest expertise in anatomy, geology, or even etymology. Gish repeated a few of O'Connell's claims of fraudulence, but even he does not stoop quite to the same depths; O'Connell's only rival in libel is another Catholic creationist, who repeats the claims in only slightly abbreviated form, even adding his own commentary about Pei's diabolical cleverness (Johnson 1982).
I will list O'Connell's main slanders, more or less in order, and follow each one with my own comments, in italics.
- All the human fossils have disappeared (but none of the animal fossils); all we have are "casts or models" (p 126).
Yes, the fossils have, tragically, disappeared; what we have are casts, not models. - The skulls did not disappear while being evacuated to America after the Japanese invasion, as the story usually goes. The Japanese did not interfere with the excavations, and in 1943 Weidenreich even wrote an article on the skulls, "and it was published in Palaeontologia Sinica, which means that the article passed through the hands of Japanese..." No, the skulls were destroyed by Dr Pei "in order to remove the evidence of fraud on a large scale" (p 127).
In his 1943 monograph, Weidenreich thanked some American associates "who consented to have this paper printed and edited in the United States as a monograph of the Palaeontologia Sinica where my main reports on the Sinanthropus material have previously appeared". In dedicating it to his Chinese colleagues and to Teilhard, he made it very clear that the Japanese had indeed made the work completely impossible and that this is why he published his monograph in the USA but in a Chinese series. As for Pei's destroying the fossils...! - After the war, Dr Pei resumed excavation at Zhoukoudian and found animal fossils, but "no more tell-tale skulls of Sinanthropus" (p 128).
Nonsense. The Zhoukoudian Lower Cave at Locality 1 had been almost emptied by the excavations of the 1930s, but another mandible was nonetheless discovered in 1959, and two cranial fragments in 1966. These latter, incidentally, completed one of the crania found in the 1930s, and they fit the surviving cast exactly — a tribute to the high quality of the original casts. - Earlier limestone quarrying and burning at Zhoukoudian had undermined the hill, causing a landslide, burying everything "under thousands of tons of stone". The so-called fossil deposits result from this burial. The stone tools were actually the remains of quartz stones used to construct the lime kilns. The so-called hearths were from the lime kilns. The modern human skulls were some of the miners. The so-called Sinanthropus skulls were those of local baboons and macaques (p 128–9).
The hill was a lime quarry, but there is no evidence for kilns or a landslide. The cave fill was consolidated. Black and others (1933: 6) write, "...the deposit of Locality 1 had been partially exposed at the head of an abandoned quarry..." - The discovery of modern humans, as well as Sinanthropus, had been concealed by Weidenreich and Pei for 5 years; there is no justification for representing them as being later in time, "for both were found buried under the same landslide" (p 130, 143–4).
Nonsense; papers were published on the near-modern human remains by Black in 1933 and by Pei in 1934 (see Weidenreich, 1939, 205, n 2). They came from the Upper Cave, higher up the same hill as the Lower Cave (Locality 1). - A skullcap found in 1928 or 1929 was described by Black in 1931 as being "more like man than ape, with a brain capacity more than twice that of a monkey" (p 133), but in 1930 Teilhard described it as a skull, not a skullcap, with a "probably small" cranial capacity and with close similarities to the great apes in length of face, brow ridges, postorbital constriction, receding forehead, triangular (not oval) skull shape seen from behind, and form of the tympanic bone (p 135). O'Connell concludes from this that "it was the skull of a baboon or monkey, for no fossils of apes have been found in China" (p 136).
That Black emphasized the human features and Teilhard was bound to describe its "ape-like" features says more about the intellectual climate of the times than about the characteristics of the specimen. What is more important is that O'Connell obviously does not know that anatomists use "skull-cap" for anything from the upper vault (calotte) to the major part of it (calvaria), so there is no contradiction at all between the way Black and Teilhard characterized it. - Boule published a paper in 1937 in which he described the skulls as "monkey-like" (p 137).
Boule did not describe them as "monkey-like" (see Ritchie 1991). - Boule also revealed that in all of them "there was a hole in the top of the skull at the occiput, supposed to have been made for the purpose of extracting the brain" (p 137), but there was no such hole shown in the photos published by Black in 1931, which was therefore not the actual skull at all but "an artificial model of the mythical Sinanthropus" (p 138).
So O'Connell does not know where the occipital bone is! (I thought that Catholic priests, before Vatican II, were supposed to know Latin.) Boule wrote (1937: 8), "La partie centrale, c'est-à-dire le poutour du trou occipital, a été détruite" (the central part, that is to say the area adjacent to the occipital "hole", has been destroyed); the occipital bone is at the back of the skull and extends onto the base, and the "trou occipital" is the foramen magnum, on the underside of the braincase. - Black estimated the brain capacity at 960 cc, later corrected by Weidenreich to 915 cc, but Teilhard had described the skull as small and resembled that of an ape — more evidence that the model was not even a cast but "a creature of the imagination" (p 139).
It is clear that "small" is a relative term — in this case, small relative to modern humans. - Weidenreich alleged that three more Sinanthropus skulls had been discovered in 1936, but no photographs of them have ever been published, only of three incomplete skulls (that is, of the "artificial models") in a brief article in 1937. Nonsense. Photographs and x-rays of all of them (Skulls X, XI, and XII are the ones in question) were published in Weidenreich's 1943 monograph, which O'Connell mentions but does not appear even to have glanced at.
- Teilhard stated, in a 1937 article, that the fossils were found in a cave, but "the existence of any natural cave at either the lower or the upper level is denied categorically by Weidenreich" (p 151).
Nonsense. Weidenreich many times (1939, 1943, and elsewhere) mentioned both the Lower Cave, where "Peking Man" was discovered, and the Upper Cave, at the top of the hill, where the near-modern specimens were found.
He brought home a great quantity of bones of various animals, two simian teeth, the thigh bone of a man, and the cap of a skull which some say is that of a man, others, that of an ape, and others still, that of a "missing link". As the brain case is missing, it is not possible to decide to which category it belongs.von Koenigswald, he reports, made a final attempt to find more specimens of Java Man in the 1930s, but all he produced was
He brought home at the same time two human skulls, known as the Wadjak skulls, of large brain capacity... Dr Dubois concealed these on his return... He produced them, however, in 1925, 30 years later... (p 159).
parts of four skulls so broken that the brain capacity could not be determined. Romer, in Man and the Vertebrates, describes these as "three more skullcaps, a lower jaw and an upper jaw". ...As there were only skullcaps, it is impossible to tell what was the brain capacity, but Romer, Vallois and other propagandists for the man-from-ape theory, give the capacity as much the same as that given by Dr Dubois' first specimen — between 800 and 900 cc (p 161)."Skullcaps" again! Had O'Connell ever seen any of them, even photographs? All four — Dubois's from Trinil, and von Koenigswald's from Sangiran — are substantial specimens, from which it is easy to obtain cranial capacities. This is also the case for at least three of the many, many specimens which have been discovered since then, mainly by Indonesian scholars. As for the Wadjak (now Wajak) skulls, they were not "concealed", but described by Dubois in three separate papers in the 1890s (Brace 1987).
What do we make of O'Connell? His motives are evident: an old-fashioned Catholic, desperately struggling against the modernizers whose efforts to bring the church, kicking and screaming, into the Enlightenment — no, into the Renaissance — finally began to bear fruit in Vatican II. Like some other traditionalists, and even some not-so-traditionalists (see Scharle 1999), he harbors a deep well of hatred against his opponents (witness his unedifying attacks on the reputation of Teilhard de Chardin). Because he has right on his side, he can destroy the reputations of those who incur his detestation without a second thought: fortunate for him, perhaps, that by the time of his first edition all his targets were either dead or, in the case of Pei, alive but isolated from outside contact in Mao's China. He is aided in his crusade by his astonishing invention of whole new scenarios, his willful disdain for actually reading the books and papers that he disparages, his triumphant ignorance of anatomy — he does not even know what the words mean, and quite obviously he does not want to know.
It says a lot about Gish that he takes this poisonous garbage as his primary, no, his only source on "Peking Man" and "Java Man" — that he is willing to lower himself to the level of this unspeakable nastiness. And let us, perhaps, raise at least one, whispered cheer for Marvin Lubenow who has managed to avoid it — although he must surely know about it, he never endorses it. But he and others of his sort might merit some respect from us, their critics, if they joined forthrightly in its condemnation.
References
Black D, Teilhard de Chardin P, Young CC, Pei WC. Fossil man in China. Geological Memoirs, Geological Survey of China, 1933; Series A, nr 11.Boule M. Le Sinanthrope. L'Anthropologie, 1937; 47: 1–22.
Brace CL. Creationists and the Pithecanthropines. Creation/Evolution 1987; nr 19: 16–23.
Jia L, Huang W. The Story of Peking Man. Beijing: Foreign Languages Press, 1990.
Johnson JWG. The Crumbling Theory of Evolution. Brisbane: Queensland Binding Service. 1982.
van Oosterzee P. Dragon Bones: The Story of Peking Man. St. Leonards, New South Wales: Allen & Unwin, 1999.
Ritchie A. The creation science controversy — a response to deception. Australian Biologist, 1991; 4 (1): 116–21.
Scharle T. Book review: Did Darwin Get it Right? Catholics and the Theory of Evolution. RNCSE 1999 Nov/Dec; 19 (6): 42–3.
Shapiro HL. Peking Man. London: George Allen & Unwin, 1974.
Weidenreich F. On the earliest representatives of modern mankind recovered on the soil of East Asia. Peking Natural History Bulletin 1939; 13: 161–74.
Weidenreich F. The skull of Sinanthropus pekinensis. Palaeontologia Sinica 1943, new series D, nr 10.
Review: A Kansan's Guide to Science
The Kansas Geological Survey is one of the nation's largest geological surveys and has a well-deserved reputation for excellence. It was therefore with some measure of excitement that I wrote away for a copy of this new science-education publication. My anticipation was honed to a sharper edge by the recent successful battle to keep science in the newly revised K–12 science standards for Alabama.
Not long ago, Kansas scientists and educated persons everywhere received a wake-up call from the Kansas Board of Education (BOE). Responses varied. Some Kansas responded with their votes, and the election of new members to the Kansas BOE resulted in dramatic improvements to the state's science standards. Some scientists responded by writing this book. As the authors put it: "the challenges to the immensity of geologic time, the nature of evolution, and the origin of the universe that motivated the BOE decision [to eliminate or de-emphasize these topics in the Kansas public school curriculum] were ... not backed up by any actual data." The authors of this book (two of whom, Adrian L Melott and Roger L Kaesler, are NCSE members) set out to create a resource that would help nonscientists learn about science and specifically about evolution. If their goal was to produce a concise, clear, and accurate account, then they succeeded.
The book contains four chapters: "The nature of science", "Understanding evolution", "The history of the earth and the history of life", and "The origin of the universe". In "The nature of science", the authors explain the scientific method, making clear the distinction between the experimental and historical sciences, but also drawing attention to their similarities. For instance, both depend on the development of testable hypotheses. Pseudoscience is contrasted with legitimate science: "Creation science, unlike legitimate sciences, does not seek to derive explanations through observations and testing of the natural world but instead begins with a belief system and then seeks to find evidence to support this view."
The second chapter, "Understanding evolution", addresses topics such as the nature of evolution, facts and theories, and the evidence for evolution. The authors make some important points: for example, that "people ask scientists and teachers, in the interest of fairness, to present the evidence against evolution. Scientists and teachers do not present such evidence because there simply is no such evidence". I think that the authors miss the boat in their otherwise excellent discussion of microevolution and macroevolution. They make no mention of historical examples of macroevolution, of which there are many (for example, Grant 1966; Filchak and others 2000; Greene and others 2000; Hendry and others 2000; Pfrender and others 2000).
"The history of the earth and the history of life" covers just that, with an emphasis on what was happening in Kansas. Despite the regional focus, the chapter is comprehensive and its contents are relevant globally. In "The origin of the universe", the authors summarize the history of the universe in 1.5 pages. The Big Bang theory is really the only topic treated adequately in this section, but it is the most important in the context of the creationist opposition to evolution. The book ends with a short list of references, a brief glossary, and suggested readings and educational resources.
A Kansan's Guide to Science obviously draws heavily on other recent publications about the nature of science. It would be a good model for anyone contemplating writing a booklet on the subject. The book's strengths include a low price, conciseness, and clarity. Its chief weakness is also one of its strengths: brevity. I recommend this book especially for people who know little about science and want a quick introduction. If you know a little and want to know a lot more, this is not for you.
Not long ago, Kansas scientists and educated persons everywhere received a wake-up call from the Kansas Board of Education (BOE). Responses varied. Some Kansas responded with their votes, and the election of new members to the Kansas BOE resulted in dramatic improvements to the state's science standards. Some scientists responded by writing this book. As the authors put it: "the challenges to the immensity of geologic time, the nature of evolution, and the origin of the universe that motivated the BOE decision [to eliminate or de-emphasize these topics in the Kansas public school curriculum] were ... not backed up by any actual data." The authors of this book (two of whom, Adrian L Melott and Roger L Kaesler, are NCSE members) set out to create a resource that would help nonscientists learn about science and specifically about evolution. If their goal was to produce a concise, clear, and accurate account, then they succeeded.
The book contains four chapters: "The nature of science", "Understanding evolution", "The history of the earth and the history of life", and "The origin of the universe". In "The nature of science", the authors explain the scientific method, making clear the distinction between the experimental and historical sciences, but also drawing attention to their similarities. For instance, both depend on the development of testable hypotheses. Pseudoscience is contrasted with legitimate science: "Creation science, unlike legitimate sciences, does not seek to derive explanations through observations and testing of the natural world but instead begins with a belief system and then seeks to find evidence to support this view."
The second chapter, "Understanding evolution", addresses topics such as the nature of evolution, facts and theories, and the evidence for evolution. The authors make some important points: for example, that "people ask scientists and teachers, in the interest of fairness, to present the evidence against evolution. Scientists and teachers do not present such evidence because there simply is no such evidence". I think that the authors miss the boat in their otherwise excellent discussion of microevolution and macroevolution. They make no mention of historical examples of macroevolution, of which there are many (for example, Grant 1966; Filchak and others 2000; Greene and others 2000; Hendry and others 2000; Pfrender and others 2000).
"The history of the earth and the history of life" covers just that, with an emphasis on what was happening in Kansas. Despite the regional focus, the chapter is comprehensive and its contents are relevant globally. In "The origin of the universe", the authors summarize the history of the universe in 1.5 pages. The Big Bang theory is really the only topic treated adequately in this section, but it is the most important in the context of the creationist opposition to evolution. The book ends with a short list of references, a brief glossary, and suggested readings and educational resources.
A Kansan's Guide to Science obviously draws heavily on other recent publications about the nature of science. It would be a good model for anyone contemplating writing a booklet on the subject. The book's strengths include a low price, conciseness, and clarity. Its chief weakness is also one of its strengths: brevity. I recommend this book especially for people who know little about science and want a quick introduction. If you know a little and want to know a lot more, this is not for you.
Acknowledgments
The references on historical speciation were given to me by the evolutionary biologists Victor Albert and Brian Axsmith.References
Filchak KE, Roethele JB, Feder JL. Natural selection and sympatric divergence in the apple maggot Rhagoletis pomonella. Nature 2000 Oct. 12; 407: 739–42.Grant V. The origin of a new species of Gilia in a hybridization experiment. Genetics 1966; 54:1189–99.
Greene E, Lyon BE, Muehter VR, Ratcliffe L, Oliver SJ, Boag PT. Disruptive sexual selection for plumage coloration in a passerine bird. Nature 2000 Oct 26; 407: 1000–3.
Hendry AP, Wenburg JK, Bentzen P, Volk EC, Quinn TP. Rapid evolution of reproductive isolation in the wild: evidence from introduced salmon. Science 2000 Oct 20; 290: 516–9.
Pfrender ME, Spitze K, Lehman N. Multi-locus genetic evidence for rapid ecologically based speciation in Daphnia. Molecular Ecology 2000 Nov; 9: 1717–35.
[Copies of this publication are available from the publications office of the Kansas Geological Survey (785-864-3965). The cost is $7.50 per copy, plus $3.00 postage and handling. Kansas residents should add 6.9% sales tax.]