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.]

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):

1. It is guided by natural law;
2. It has to be explanatory by reference to natural law;
3. It is testable against the empirical world;
4. Its conclusions are tentative, that is, they are not necessarily the final word; and
5. 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 .

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.]

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.

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.

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.

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.

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.

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:
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.

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.

• 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.

Through teamwork, effective communication, and perseverance, our group succeeded in encouraging the local school district to ensure that students at the high school receive a sound science education. We are still following the situation to ensure that there is long-term compliance by the teacher with the district's instructions.

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."

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.