Volume 23 (2003)

RNCSE 23 (1)RNCSE 23 (1) RNCSE 23 (2)RNCSE 23 (2)

RNCSE 23 (3-4)RNCSE 23 (3-4):
Special double issue.
RNCSE 23 (5-6)RNCSE 23 (5-6):
Special double issue.

RNCSE 23 (1)

Reports of the National Center for Science Education
Volume: 
23
Issue: 
1
Year: 
2003
Date: 
January–February
Articles available online are listed below.

Cobb County Clarifies: Teach Only Science in Science Classes

Reports of the National Center for Science Education
Title: 
Cobb County Clarifies: Teach Only Science in Science Classes
Author(s): 
Skip Evans
NCSE Network Project Director
Volume: 
23
Issue: 
1
Year: 
2003
Date: 
January–February
Page(s): 
4
This version might differ slightly from the print publication.
On January 8, 2003, the Cobb County, Georgia, School District issued guidelines that clarify the new "Theories of Origins" policy (see RNCSE 2002 Sep/Oct; 22 [5]: 11-2). The guidelines are available on-line at http://www.cobbk12.org/~boardpolicies/I_Policies/idbd_r.htm.

Although the "Theories of Origins" policy — adopted by the Cobb County Board of Education on September 26, 2002 — explicitly stated that it is "not to be interpreted to restrict the teaching of evolution; [or] to promote or require the teaching of creationism", its treatment of evolution is not entirely satisfactory. Although it is certainly true, as the policy states, that evolution is a "subject [that] remains an intense area of interest, research, and discussion among scholars", no attempt is made to clarify that evolution, as the common descent of living things, is not a matter of dispute within the scientific community. The "interest, research, and discussion among scholars" is about controversies over how — not whether — evolution occurred. Thus the policy as worded is likely to encourage those wishing to promote "alternatives" to evolution.

The new guidelines largely rectify the problem by clarifying the nature of the controversy over evolution: "It is recognized that instruction regarding theories of origin is difficult because it is socially controversial and potentially divisive" (emphasis added). There is no mention in the guidelines of any supposed scientific controversy over evolution or of any supposed scientific "alternatives" to it. Curt Johnston, the chairman of the Cobb County Board of Education, told the Atlanta Journal-Constitution (2003 Jan 9) that "Encouraging discussion of that might be illegal", evidently alluding to faith-based views such as "intelligent design".

Reviewing the guidelines, Eugenie C Scott, the executive director of the National Center for Science Education, commented, "When the 'Theories of Origins' policy was adopted, I said that the Cobb County Board of Education was sending mixed signals to teachers and citizens. With these guidelines, the board's message is loud and clear: teach only science in science classes. This is good news for the education of the children of Cobb County."

The clarification of the "Theories of Origins" policy also won approval from the American Civil Liberties Union. Michael Manely told the Marietta Daily Journal (2003 Jan 9) that, in light of the guidelines, the ACLU has decided not to file suit over the "Theories of Origins" policy. "It certainly seems that the board is telling the teachers to back down on the teaching of creationism, 'intelligent design' or other faith-based theories", he said. In August 2002, the ACLU filed suit over the textbook disclaimer mandated by the Cobb County Board of Education that refers to evolution as "a theory, not a fact" (see RNCSE 2002 Sep/Oct; 22 [5]: 9-11).

Prominently mentioned in the Daily Journal's article was the recently formed Georgia Citizens for Integrity in Science Education (www.georgiascience.org), a grassroots organization dedicated to promoting scientific literacy and excellence in science education in Georgia's public schools. "The members of GCISE have worked hard to ensure that evolution is taught in the Cobb County public schools as the unifying, important, and vital science that it is", said NCSE's Scott. "Everyone who cares about a quality science education for the students of Georgia's public schools is indebted to them."

About the Author(s): 
Skip Evans
NCSE
PO Box 9477
Berkeley CA 94709-0477
evans@ncseweb.org

My Favorite Pseudoscience

Reports of the National Center for Science Education
Title: 
My Favorite Pseudoscience
Author(s): 
Eugenie C. Scott
NCSE Executive Director
Volume: 
23
Issue: 
1
Year: 
2003
Date: 
January–February
This version might differ slightly from the print publication.
Paul Kurtz’s letter inviting me to write this article suggested that I describe “my own personal involvement” in the skeptical movement. My introduction to skepticism was a fascination with a particular pseudoscience, “creation science”. From the day I first heard this phrase, I was hooked.

In 1971, I was a graduate student in physical anthropology at the University of Missouri. One day, my professor, Jim Gavan, handed me a stack of small, brightly colored, slick paper pamphlets from the Institute for Creation Research. “Here”, he said, “Take a look at these. It’s called ‘creation science.’”

Wow. Here I was studying to be a scientist, and here were people calling themselves scientists, but we sure were not seeing the world the same way. They were looking at the same data: the same fossils, the same stratigraphy, the same biological principles, and so on. But from these data, creationists were concluding that all living things had appeared in their present form, at one time, a few thousand years ago. I was concluding that living things had branched off from common ancestors over scarcely imaginable stretches of time. They were concluding that the entire planet had been covered by water, and that all the present-day geological features of earth had been determined by this flood and its aftermath. I could not see any evidence for this at all, and much evidence against it. Why were we coming up with such different conclusions? The data were not all that different, but the philosophy of science and the approach to problem solving sure were.

I began collecting “creation science” literature as an academic enterprise: an interesting problem in the philosophy of science and critical thinking. Due to the pressures of graduate school and my first teaching job, I was not able to pursue it especially deeply, but students would occasionally bring up the topic. I would tell them that even if proponents of “creation science” claimed they were doing science, one cannot claim that one is doing science if one is doing something very different from what scientists are doing. “Creation science” was a good foil to use in teaching students about the nature of science.

Philosophers of science can — and do — argue incessantly over the definition of science. I do not know how many academic papers have been written attempting to solve the “demarcation problem”: what qualifies as science and what does not. Some partisans even go so far as to claim that science is impossible to define. I confess to having little tolerance for such “how many angels can dance on the head of a pin” type discussions. In my present job as executive director of the National Center for Science Education, I regularly encounter the public’s misunderstanding of the most basic elements of science. I deal with people who nod in agreement with a typical creationist statement that “neither evolution nor creationism is scientific because no one was there to observe it”. I deal with people who agree with creation scientists stating that “evolution is not scientific because evolutionists are always changing their minds”. A very popular view is that we should “give the kids all the options” in a science classroom, and teach them both data demonstrating that evolution took place and “the evidence” for the “alternate theory” that God created everything at one time in its present form — two mutually exclusive views.

Against such a background, the philosopher’s discussion of the nuances of the demarcation problem become an intellectual luxury far removed from what people need to hear. Doubtless to the frustration of my colleagues in the philosophy of science, my job requires me to simplify — probably far beyond what they consider acceptable. But in doing so, I can make a little progress in helping the public to understand why science works, and also why “creation science” is not science. Maybe down the road the nonscientists I encounter can tackle falsificationism and the demarcation problem; right now, I would be happy if they understood two basic rules of science that I believe the majority of scientists would agree upon — however much they might disagree on others. And — more importantly for this discussion — “creation science” can be rejected as science based even on this simplest of understandings of what science is.

The nature of science
There are two basic principles of science that creationism violates. First, science is an attempt to explain the natural world in terms of natural processes, not supernatural ones. This principle is sometimes referred to as methodological naturalism. In time, a consensus of how some aspect of nature works or came about is arrived at through testing alternate explanations against the natural world. Through this process, the potential exists to arrive at a truly objective understanding of how the world works.

Please allow a digression here. I am not presenting a cut-and-dried formula — “the scientific method” — as if the process of science were a lockstep algorithm. It is much untidier than that. Of course science reflects the time and culture in which it is found. Of course scientists, being human, have biases and make mistakes. Yet the growth of knowledge in a field is not the result of individual achievement, but rather is a function of a number of minds working on the same and different problems over time. It is a collective process, rather than the result of actions of a solitary genius. Individual scientists may be biased, closed-minded, and wrong, but science as a whole lurches forward in spite of it all thanks to its built-in checks.

An important check is that explanations must be tested against the natural world. Thus there is an external standard against which a scientist’s views are measured, regardless of his biases or the biases of his opponents. Unpopular ideas may take longer to be accepted, and popular ideas may take longer to be rejected, but the bottom line determining acceptance or rejection is whether the ideas work to describe, predict, or explain the natural world. The Soviet geneticist Lysenko foisted a “Lamarckian” (inheritance of acquired characteristics) theory of heredity upon the Soviet scientific establishment because Lamarckian genetics was more politically compatible with Marxism than Mendelian genetics. His politically biased science set Soviet genetics back a full generation, but today Russians employ Mendelian genetics. Wheat raised in refrigerators does not grow any better in Siberia than regular wheat, and after a series of 5-year plans gone bust, eventually the Soviet government figured out that Lysenko had to go. “Mendelism” works; “Lysenkoism” does not.

Science is nothing if not practical. The explanations that are retained are those that work best, and the explanations that work best are ones based on material causes. Nonmaterial causes are disallowed.

The second minimal principle of science is that explanations (which is what theories are) are tentative, and may change with new data or new theory. Now, do not misunderstand me: I am not claiming that all scientific explanations always change, because in fact some do not. Nonetheless, scientists must be willing to revise explanations in light of new data or new theory. The core ideas of science tend not to change very much — they might get tinkered with around the edges — whereas the frontier ideas of science may change a lot before we feel we understand them well.

Here then are two critical strictures on modern science: science must explain using natural causes, and scientists must be willing to change their explanations when they are refuted. Viewed in the light of these two basic tenets of science, “creation science” fails miserably.

Explaining through natural cause
When a creationist says, “God did it”, we can confidently say that he is not doing science. Scientists do not allow explanations that include supernatural or mystical powers for a very important reason. To explain something scientifically requires that we test explanations against the natural world. A common denominator for testing a scientific idea is to hold constant (“control”) at least some of the variables influencing what you are trying to explain. Testing can take many forms, and although the most familiar test is the direct experiment, there exist many research designs involving indirect experimentation, or natural or statistical control of variables.

Science’s concern for testing and control rules out supernatural causation. Supporters of the “God did it” argument hold that God is omnipotent. If there are omnipotent forces in the universe, by definition, it is impossible to hold their influences constant; one cannot “control” such powers. Lacking the possibility of control of supernatural forces, scientists forgo them in explanation. Only natural explanations are used. No one yet has invented a theometer, so we will just have to muddle along with material explanations.

Another reason for restricting ourselves to natural explanations is practical. It works. We have gone a long way towards building more complete and, we think better, explanations through methodological naturalism, and most of us feel that if it ain’t broke, don’t fix it. Also, being able to say, “God (directly) did it” is a “science stopper”, in the words of philosopher Alvin Plantinga (2001). To say “God did it” means one does not need to look further for a natural explanation. For example, creationist literature abounds with criticisms of origin-of-life research. Because scientists have not yet reached a consensus on how the first replicating molecule came about, creationists argue, this is an intractable problem that should just be attributed to “God did it”. Well, if we stop looking for a natural explanation for the origin of life, surely we will never find it. So even if we have not found it yet, we must nonetheless slog on.

“Creation science”, for all its surface attempts (especially in its presentation to the general public) to claim to abide by a strictly scientific approach, relying solely on empirical data and theory, eventually falls back to violating this cardinal rule of methodological naturalism. Sometimes one has to go a bit deep in an argument, but eventually, as in the well-known Sidney Harris cartoon, “then a miracle occurs”.

For example, to a creation scientist holding to Flood Geology, Noah’s Flood was an actual historical event, and representatives of all land animals plus Noah, his wife, their sons, and their sons’ wives were on a large boat. Q: All land animals? A: Sure. The Ark is the size of the Queen Mary. Q: But there are thousands of species of beetles alone! How could all land animals be on the Ark? A: Oh, Noah did not take two of every species. He took pairs of each kind, and kinds are higher taxonomic levels than species. Q: But how could only 8 people take care of a Queen Mary-sized boat full of animals? How could they feed, water, and clean out the stalls? A: They did not have that much work, because the rocking movement of the boat caused most of the animals to estivate, or go dormant, obviating the need for feeding, watering, and stall-cleaning. Q: But the Ark floated around for almost a year before landing! Small mammals, such as mice and shrews, have a high surface–area: body–mass ratio, and have to eat almost their weight in food each day just to keep their metabolism up. These animals could not have survived estivation. A: Well, then, a miracle occurred.

Push a creationist argument far enough, and sure enough, it will become necessary to resort to a miracle. But miracle-mongering cannot be part of science.

In addition to the familiar “creation science” that got me interested in this particular pseudoscience, in the last ten years or so a newer form of anti-evolutionism has made its appearance: “Intelligent Design” (ID) creationism. ID harks back to the 1802 position of clergyman William Paley that structural complexity (such as the vertebrate eye for Paley or the structure of DNA for his latter-day bedfellows) is too complicated to have come about through a natural process. Therefore it must have been designed by an “intelligence”. The “intelligence” of course is God, and attributing natural causality to a supernatural power of course violates methodological naturalism. Recognizing that methodological naturalism is the standard of modern science, ID proponents argue that it should be scuttled, and replaced with what they call “theistic science”, which possesses the enviable ability to invoke the occasional miracle when circumstances seem to require it (Scott 1998). ID proponents are content to allow methodological naturalism for the vast amount of science that is done; they wish to leave the possibility of supernatural intervention only for those scientific problems that have theological implications, such as the Big Bang, the origin of life, the appearance of “kinds” of animals (the Cambrian Explosion), and the origin of humans. The strength of methodological naturalism is perhaps best illustrated by its general acceptance by both the ID and “creation science” wings of the anti-evolution movement — except when it comes to religiously sensitive topics.

The importance of changing your mind
So creationists violate the first cardinal rule of science, the rule of methodological naturalism, but they also violate the second cardinal rule — that of being willing to change or reject one’s explanation based on good evidence to the contrary. This is most clearly revealed by the creationist treatment of empirical data. Now, the problem is not that creationists sift through the scientific literature to find data that support the creation “model”; that in itself is not out of line. Scientists do seek confirming data (in the real world, as well as in the literature). But creationists ignore evidence that disconfirms their view, because they are not willing to change their explanations in the light of new data or theory.

Judges are not famous for their scientific acuity (witness Justice Scalia’s dissent in the 1987 Supreme Court’s Edwards v Aguillard case), but one judge got it remarkably right. William Overton, in the decision in McLean v Arkansas, wrote,
The creationists’ methods do not take data, weigh it against the opposing scientific data, and thereafter reach the conclusions stated in section 4(a).
Instead, they take the Book of Genesis and attempt to find scientific support for it.
While anybody is free to approach a scientific inquiry in any fashion they choose, they cannot properly describe the methodology used as scientific, if they start with a conclusion and refuse to change it regardless of the evidence developed during the course of the investigation.
A theory that is by its own terms dogmatic, absolutist and never subject to revision is not a scientific theory.
For decades now, creationists have claimed that the amount of meteoritic dust on the moon disproves evolution. The argument goes like this: Based on scientific measurements, the amount of meteoritic dust falling on the earth is X tons per year; a proportionate amount must also fall on the moon. If the earth and moon were ancient as evolutionists claim, then the amount of dust on the moon would be several hundreds of feet thick, since in the scant atmosphere of the moon, the dust would not burn up as it does on the earth. When astronauts landed on the moon, they found only a few inches of dust, proving that the moon is young, so the earth is young, so there is not enough time for evolution, so evolution did not happen and therefore God created the earth, moon, and everything else in the universe 10 000 years ago.

Decades ago, creationists were told that the data they use for the amount of dust falling on the earth was inaccurate. More accurate measurements of the amount of meteoritic dust influx to the earth are degrees of magnitude smaller than the original estimates cited by creationists. Before astronauts landed on the moon, satellites had accurately measured the amount of dust occurring in space, and NASA predicted that the surface of the moon would be covered by no more than a few inches of dust — exactly what astronauts found. Even though this information has been available for decades, and evolutionists time and again have pointed out flaws in the creationist argument, the dust on the moon argument still is touted as “evidence against evolution”. If this were a normal scientific theory, it would have been abandoned and forgotten long ago, an empirical stake in its heart, but this creationist zombie keeps rising again and again.

It is hard to argue that one is doing science when one can never bring oneself to abandon a refuted argument, and “creation science” is littered with such rejects. More modern forms of creationism such as “intelligent design theory” have not been around as long, and have not built up quite as long a list of refuted claims, but things do not look very good for them at this point. Michael Behe (1996) has proposed the idea that certain biochemical functions or structures are “irreducibly complex”: because all components must be present and functioning, such structures could not have come about through the incremental process of natural selection. The examples he uses in his book Darwin’s Black Box, such as the bacterial flagellum and the blood-clotting cascade, appear not to be irreducibly complex after all. Worse, even granting the theoretical possibility that an irreducibly complex structure could exist, there is no reason it could not be produced by natural selection. A (theoretically) irreducibly complex structure would not have to have all of its components assembled in its present form all at one time. The way natural selection works, it is perfectly reasonable to envision that some parts of such a structure could be assembled for one purpose, other parts for another, and the final “assembly” results in a structure that performs a function different from any of the “ancestral” functions. As complex a biochemical sequence as the Krebs cycle has recently been given an evolutionary explanation of this sort (Melandez-Hevia and others 1996).

I am willing to give “intelligent design” (ID) a little more time to demonstrate that it is, as it aspires to be, a truly scientific movement. To be able legitimately to claim that ID is scientific, however, will require that its proponents be willing to abandon ideas in the light of refuting evidence — something that their ideological ancestors, the “creation scientists”, have been unable to demonstrate, and which we have seen precious little of from the leaders of the ID movement.

Logical problems
Needless to say, in addition to violating the two key principles of science, the “science” of creationism demonstrates other weaknesses, not the least important is its logic. “Creation scientists” posit a false dichotomy of only two logical possibilities: one being special creationism as seen in a literal interpretation of Genesis, and the other being evolution. Therefore, if evolution is disproved, then creationism is proved; arguments against evolution are arguments for creationism. “Creation science” literature is largely composed of a careful sifting of legitimate scientific articles and books for anomalies that appear to “disprove” evolution.

But of course, to disprove one view is not to prove another; if I am not at home in Berkeley, that does not mean I am on the moon. Accepting the “if not A, then B” form of argument requires that there are only two possibilities. If the only two possibilities are that I am in Berkeley or on the moon, then indeed, evidence that I am not in Berkeley is evidence that I am on the moon, but clearly there are more than two alternatives as to my whereabouts. Similarly, there clearly are far more alternatives to scientific evolution than biblical creationism. There are several Hopi origin stories, several Navajo ones, scores of other Native American views, several dozen sub-Saharan African tribal explanations, and we have not even looked at South Asia, Polynesia, Australia, or views no longer held such as those of the ancient Norse and ancient Greeks. Even if evolution were disproved, biblical literalists would have to find ways of disproving all of these other religious views, so the logic fails.

More than an academic exercise
For many years, then, my interest in creationism was largely academic. It was an interesting exercise in the philosophy of science. But a few years after I left Missouri, my professor Jim Gavan unwisely accepted an invitation to debate the ICR’s Duane Gish. Gish had perfected a hugely effective technique for persuading the public that evolution was shaky science, and that folks should really consider his “scientific alternative”. I and some of my Kentucky students drove from Lexington to Missouri to attend the debate, and it was an eye-opener. I counted 13 buses from local church groups parked outside the big University of Missouri auditorium, and after seeing the enthusiasm with which the audience received Gish and his message, the cold water of the social and political reality of this movement hit me for the first time. It was no longer just an academic exercise. People were taking this pseudoscience very seriously.

The late Jim Gavan was an excellent scientist, a former president of the American Association of Physical Anthropology, a smart and articulate man well-grounded in philosophy of science. He had done his homework: he had studied creationist literature for several months and came as prepared as anyone could be expected to be. Clearly, his scientific arguments were superior, but from the perspective of who won the hearts and minds of the people, Gish mopped him up.

So I realized that there was a heck of a lot more in this creationism and evolution business than just the academic issues. I went back to Lexington and my job of teaching evolution to college students with a new appreciation of a growing movement that had as its goal the undermining of my professional discipline, to say nothing of the scientific point of view. But still — there were pressures to publish, and a high teaching load, and I was still learning my job, so I did not take an active role in the controversy quite yet.

Then in 1976, I went to the University of Kansas in Lawrence, as a visiting professor. As I walked across campus one day, I saw a poster advertising a debate between two professors, Edward Wiley and Pat Bickford with Duane Gish and Henry Morris from the ICR. My first thought was, Do these guys know what they are getting in for? I jotted down the names of the professors and called up Ed Wiley. I told him that I had a collection of creationist materials that I was happy to make available to him, and offered to discuss the upcoming debate with him some time. We met and shared resources, and because of Ed’s strategy I began to think that maybe this debate would be different.

Gish’s usual stock in trade was to attack Darwinian gradualism because virtually all of his evolutionist opponents defended it. Ed Wiley had recently arrived from the American Museum of Natural History, where he had been converted to some new approaches to evolutionary biology that Gish had not heard of yet. Whereas Gish anticipated that his opponent would defend Darwinian gradualism, Ed merely sniffed that Dr Gish had not kept up on the latest scholarship and went on to explain punctuated equilibria and cladistics. Worse for Gish, not only did Wiley ignore Darwinian gradualism, he almost ignored evolution completely, concentrating instead on attacking “creation science” as being a nonscience, and as being empirically false.

This debate was a disaster for the creationism side. Gish did not know what to say: his target had disappeared, and he was faced with new information with which he was totally unfamiliar (needless to say, by his next debate, he had figured out a “refutation” of punctuated equilibria, and no other evolutionist opponent would ever catch him unprepared on this topic). It was pleasant to behold, especially after having seen my mentor and friend Jim Gavan skunked by Gish a couple of years before.

But the most memorable moment in the debate did not have anything to do with science. Geologist Pat Bickford was paired with the avuncular founder of creation science, Henry M Morris, and did a good job showing the scientific flaws of Morris’s “flood geology model” (according to which all the world’s important geological features were formed by Noah’s Flood), although I do not know how many in the audience understood much of his technical presentation. As with the Gavan/Gish debate, the audience was dominated by people who had arrived on buses from regional churches, and they were there to cheer their champions Gish and Morris. I was sitting behind a young girl of 11 or so and her mother.

Bickford began his presentation by pointing out that he was an active churchgoer, had been one for many years, and found this not at all incompatible with his acceptance of evolution. The girl in front of me whirled to face her mother and said, “But you told me —” and her mother, equally shocked and intent on hearing more, said, “Shhhhhhhh!” They had come to the debate convinced that one had to choose between evolution and religion. Bickford’s testimonial exposed them to empirical evidence that this was not true. I suspect that they wondered what else they had been told that was not true. I noticed that they listened to Bickford far more intently than they had listened to Wiley and left with a thoughtful look in their eyes.

But my true baptism into realizing the depth and extent of the social and political importance of the “creation science” movement came in 1980 in Lexington, Kentucky, when the “Citizens for Balanced Teaching of Origins” approached the Lexington school board to request that “creation science” be introduced into the curriculum. Because I had a collection of creationist literature collected over the years, I became a focal point for the opposition to this effort. After over a year of controversy, our coalition of scientists and liberal and moderate clergy (who objected to biblical literalism being presented in the public schools) managed to persuade the Lexington Board of Education to reject the proposal — by a scant 3–2 margin.

Creationism and Pseudoscience
What happened in Lexington has happened in community after community across the United States, although the evolution side has not always prevailed. I learned from the Lexington controversy (and from observing creation/evolution debates) that “creation science” is not a problem that will be solved merely by throwing science at it. And I suspect that this is generally also the case with other pseudosciences. Like other pseudosciences, “creation science” seeks support and adherents by claiming the mantle of science. Proponents argue that “creation science” should be taught in science class because it supposedly is a legitimate science. This point must be refuted, and scientists are the best ones to make the point. But showing that creationism is unscientific (and just plain factually wrong) is insufficient, however necessary. People who support “creation science” do so for emotional reasons, and are reluctant or unwilling to relinquish their belief unless those needs or concerns are otherwise assuaged. I suspect the same thing can be said for believers in UFOs, or out-of-body experiences, or paranormal phenomena in general: these beliefs are meeting some emotional needs, and consequently will be very difficult to abandon.

In the case of creation science, the needs being met are among those associated with religion, which makes the adherence to creationism particularly difficult to give up. Creationism is most closely associated with a particular theology of special creationism; not all religion is inimical to evolution, as demonstrated both by scientists who are religious and religious non-scientists who accept evolution. But if your theology requires you to interpret your sacred documents in a literal fashion (whether the Bible, the Torah, the Koran, or the Vedas), in most cases, evolution will be difficult to accommodate with faith.

Some anti-evolutionists — most of the ID supporters, for example — think that evolution is incompatible with faith not because their theology is biblically literalist, but because they believe that a God who works through evolution is too remote; their theology requires a very personal God who is actively involved with individual human lives and who therefore gives purpose and meaning to life. The God of the theistic evolutionist, the one who uses evolution to construct living things much as Newton’s God used gravitation to construct the solar system, is too distant; evolution to them is a step down the slippery slope toward deism.

But whether in the form of biblical literalism or not, religious sensibilities are the engine driving anti-evolutionism. Religion is a powerful force in human lives. If religion did not meet many human needs, it would not be a cultural universal; obviously we are dealing with many complex psychological issues. No matter how sound Jim Gavan’s science was during his debate with Gish, he failed to move most of his listeners because they came to the debate convinced that evolution was fundamentally incompatible with their religion. Pat Bickford’s casual mention that he was a churchgoer was critical to the success of the Kansas debate, because it forced audience members to grapple with a new idea: that one could be an evolutionist and also a Christian. In Lexington, scientists could point out that “creation science” was not science, but the clergy could assuage the public’s emotional concerns that by “believing” in evolution, they were giving up something important to them. Scientists alone could not have won the day. If 95 clergymen had not signed a petition stating that evolution was fine with them and that they felt that the schools should not be presenting a religious doctrine as science, community sentiment would not have allowed the board of education to make the decision it did.

Those of us concerned about pseudoscience and its attractiveness to the public would be well advised to consider the emotional needs that are met by beliefs in ESP, alien abduction, astrology, psychic powers, and the like, and address them as well as criticizing the poor science invoked by supporters to support the pseudoscience. We skeptics sometimes feel that the people we are trying to reach are impenetrable — and some of them are! The public is divided into 3 parts: confirmed believers, confirmed skeptics, and a much larger middle group that does not know much science, but does not have the emotional commitments that might lead it to embrace a pseudoscientific view. In the case of creation science, the emotional commitment (among many) is to the particular theology of biblical literalism; in the case of UFO abductees, it may be a need for a quasi-religious benevolent protector (or conversely, the fear of an omnipresent threat against which one is powerless). I have found that I am most effective with that large middle group, and hardly ever effective with the true believers; I suspect most skeptics have had similar experiences.

But after all, reaching that large middle group is also the goal of the proponents of pseudoscience. If, like most skeptics, you feel that we would all be better off with more science and less pseudoscience, then that is where we should be focusing our energies, rather than fruitlessly arguing with people who will never agree with us. But to reach that group that is potentially reachable, we must also be aware that a scientific explanation is necessary but not sufficient to change someone’s mind; if I have learned anything from over 25 years in the skeptic business, it is that it is necessary to deal with the emotional reasons that make our species susceptible to these beliefs, as well as the scientific.

[Reprinted with permission from Skeptical Odysseys: Personal Accounts by the World's Leading Paranormal Inquirers. Paul Kurtz, ed. Amherst (NY): Prometheus Books, 2001, p 245-56.]

References

Behe MJ. Darwin’s Black Box. New York: The Free Press, 1996.
Melandez-Hevia E, Waddell TG, Cascante M. The puzzle of the Krebs citric acid cycle: Assembling the pieces of chemically feasible reactions, and opportunism in the design of metabolic pathways during evolution. Journal of Molecular Evolution 1996; 43: 293–303.
Plantinga A. Methodological naturalism? In: Intelligent Design Creationism and its Critics, ed. Pennock RT. Cambridge (MA): The MIT Press, 2001. p 339–61.
Scott EC. 1998. “Science and religion”, “Christian scholarship”, and “theistic science”: Some comparisons. Reports of the National Center for Science Education 1998 Mar-Apr; 18(2): 30-2

About the Author(s): 
Eugenie C. Scott
NCSE
PO Box 9477
Berkeley, CA 94709-0477
scott@ncseweb.org

Review: Quantum Leaps in the Wrong Direction

Reports of the National Center for Science Education
Volume: 
23
Year: 
2003
Issue: 
1
Date: 
January–February
Page(s): 
19
Reviewer: 
Andrew J Petto, University of the Arts
This version might differ slightly from the print publication.
Work under Review
Title: 
Quantum Leaps in the Wrong Direction: Where Real Science Ends and Pseudoscience Begins
Author(s): 
Charles M Wynn and Arthur W Wiggins (with cartoons by Sidney Harris)
Washington (DC): Joseph Henry Press, 2001. 226 pages (with glossary, additional reading list, and index).
Back in Madison, Wisconsin — home of the quadrennial "Psychic Faire" — it should have been no surprise to see the half-page ad for angel medium, and angel therapist, Dr Doreen Virtue. She claims that she can see, communicate, and give people access to the power of angels all around us. But how do we know that angels are responsible? Well, because Dr Virtue tells us they are. This may seem like a cover story from the Weekly World News, but it appeared in a regular daily newspaper, and Virtue's appearance drew a full house at a local theater.

Quantum Leaps is just the sort of book that should be read by anyone interested in psychics, mediums, astrologers, and others who make real-world claims about the effects of invisible powers accessible only to a select few. It gets to the heart of what constitutes science — not only the content and the theory, but also the process and reflection. Using historical and contemporary examples, the authors show us science at work — accepting, modifying, and often rejecting hypotheses, theories, and even very plausible explanations for what we observe in the world around us. The strength of the book is in the first 50 pages. Here the authors elucidate the modern scientific process with the aid of abundant diagrams, charts, and the delightful cartoons of Sidney Harris. I do not know of a clearer, more accurate, and more accessible explanation of what science is and how it proceeds than that in the first three chapters of this book.

The second part of the book looks at five major, persistent pseudoscientific ideas, recognizing that there are many more that could be added. The Wynn and Wiggins "Top Five" are UFOs and visits from extraterrestrials, astrology, out-of-body experiences and astral projections, creation "science", and parapsychology. These are important ideas that engage many of our citizens, and Wynn and Wiggins review the main claims and some of the history of these ideas.

Unfortunately, the book misses an opportunity in this section to take the reader through a consistent examination of these ideas based on the characteristics of scientific investigation laid out in the first part of the book. Their rejection of these pseudosciences is often didactic, even authoritarian, and does not shed as much light on why we should reject these ideas as the introductory chapters seem to promise. None of their statements about these pseudoscientific ideas is incorrect; it is just that they often do little more than tell us that the pseudoscientific idea is wrong — only occasionally exploring which aspects of good scientific practice are violated by the pseudoscience in question.

Still, the book is valuable overall and a good resource for those interested in (or faced with confronting) pseudoscientific ideas in the classroom, in civic life, or in politics. It provides the framework within which one could hold the Wynn and Wiggins "Top Five" up to the scrutiny of the practice of real science, as laid out in the introductory chapters. There is also a solid glossary followed by a good selection of further readings for those more interested in particular topics. During our recent struggle in Pennsylvania over science education standards, I considered buying a copy for each member of the State Assembly's two education committees. It would have been a worthwhile investment.

About the Author(s): 
Andrew J Petto
University of the Arts
320 S Broad St
Philadelphia PA 19102-4994
editor@ncseweb.org

Review: The Antiquity of Man

Reports of the National Center for Science Education
Volume: 
23
Year: 
2003
Issue: 
1
Date: 
January–February
Page(s): 
22
Reviewer: 
Tom Morrow
This version might differ slightly from the print publication.
Work under Review
Title: 
The Antiquity of Man: Artifactual, Fossil, and Gene Records Explored
Author(s): 
Michael Brass
Baltimore: Publish America, 2002. 220 pages, bibliography.
When I learned that someone wrote a book-length rebuttal to Michael Cremo and Richard Thompson's Hindu creationist tract Forbidden Archaeology: The Hidden History of the Human Race — a 900-page exposé of "anomalous archaeological artifacts" that suggested modern people lived on earth 4 billion years ago — my first reaction was, "Why would somebody go to the trouble?"

It has been a long time since I read Cremo and Thompson's 1993 book, but I immediately recalled how they devoted hundreds and hundreds of pages to reconstructed drawings of "eolith" stones, lifted from reports published a century or more ago, for relics that no longer existed and could not be re-examined. By the time I reached their chapter that suggested that Big Foot and the Yeti were living hominids whose existence was being suppressed by "establishment scientists", I dismissed it as a typical creationist fantasy.

Just as Christian creationists attempt to harmonize science with the Bible, Michael Cremo and Richard Thompson are Hindu creationists who attempt to harmonize science with their sacred Vedic scriptures such as the Bhagavata Purana, which describes how men and women have lived on earth for a vast period of time called the Day of Brahma that encompasses a thousand "yuga" cycles totaling 4.32 billion years.

Michael Brass, an archaeologist from Cape Town, South Africa, wrote a lengthy rebuttal to Cremo and Thompson's book entitled The Antiquity of Man: Artifactual, Fossil and Gene Records Explored. But Brass's book is not a tit-for-tat response to Cremo and Thompson's book. Instead, he mostly summarizes the vast archaeological and paleoanthropological evidence for human evolution from a huge variety of scientific sources. His specific criticisms of Cremo and Thompson are sparse yet devastating because he shows how they borrow the same discredited tactics that Christian creationists have used in their literature for ages.

For example, Brass shows how Cremo and Thompson selectively quote paleoanthropologist Russell Tuttle to imply that he believed that the 3.5 million-year-old Laetoli footprints were made by an anatomically modern human, despite the fact that Tuttle's report clearly said they were made by a hominid of indeterminate species. Cremo and Thompson give enormous weight to Solly Zuckerman's and Charles Oxnard's dissenting opinions of the Australopithecine fossils while completely ignoring the dozens of scientific papers that thoroughly document Zucker-man's and Oxnard's errors.

Brass also reveals how Cremo and Thompson misunderstand basic scientific principles. For example, they reject the recent radiocarbon date of the Hans Reck skeleton because they allege that it could have been contaminated by an intrusive burial. But even if that happened, such an error would make the specimen appear incorrectly older than its actual age, not younger. Cremo and Thompson also endorse Louis Leakey's discredited opinion that Neanderthals were hybrids that resulted from interbreeding between Homo sapiens and Homo erectus. But if, as they insist, modern humans lived on earth for hundreds of millions of years without change, these Homo sapiens would have been genetically incapable of interbreeding with another species.

I do disagree with Brass's discussion of the biological role of homeobox (Hox) genes that guide the construction of the axis and limbs of animals. Brass's presentation primarily relies upon Jeffrey Schwartz's Sudden Origins: Fossils, Genes and the Emergence of New Species (New York: John Wiley & Sons, 1999). Schwartz is a paleontologist, not a biologist, and most biologists I have talked to insist that Schwartz's book has serious flaws.

For specialists, a more reliable book about Hox genes is Wallace Arthur's book The Origin of Animal Body Plans: A Study in Evolutionary Developmental Biology (Cambridge: Cambridge University Press, 1997; see review by Laurie Godfrey on page 35). For the non-specialist, I recommend Carl Zimmer's breezy book At the Water's Edge (New York: Touchstone Press, 1999).

But this is a minor disagreement. Michael Brass's book is an excellent resource that thoroughly covers the most current archaeological and paleoanthropological findings in human evolution.

About the Author(s): 
Tom Morrow
662 Hogskin Valley Road
Washburn TN 37888
felidae990@msn.com

Review: The Creation Controversy & the Science Classroom

Reports of the National Center for Science Education
Volume: 
23
Year: 
2003
Issue: 
1
Date: 
January–February
Page(s): 
20–22
Reviewer: 
Brian Alters, McGill University
This version might differ slightly from the print publication.
Work under Review
Title: 
The Creation Controversy & the Science Classroom
Author(s): 
James W Skehan and Craig E Nelson
Arlington (VA): NSTA Press, 2000. 56 pages.
One of the greatest needs for biology instruction is an understanding of why many students consider a fundamental theory of science to be faulty and what to do about it pedagogically. A deeper understanding of students' underpinning religious beliefs concerning evolution, the age of the earth, and science in general benefits biology instructors (and other science instructors as well) in helping to comprehend students' learning roadblocks, why the roadblocks exist, the history of the roadblocks, and why everyone does not share such roadblocks. Naturally such an understanding is helpful, but also important is how instructors can nevertheless increase student understanding of such a publicly controversial topic as evolution.

Appropriately, the National Science Teachers Association published a 56-page booklet containing two chapters responding to these two needs of understanding and strategies: The Creation Controversy & the Science Classroom. The work is divided into two chapters, each addressing one of these needs: "Modern Science and the Book of Genesis" by James Skehan and "Effective Strategies for Teaching Evolution and Other Controversial Topics" by Craig Nelson.

In his chapter, Skehan — an NCSE Supporter — starts by taking readers through why people believed in a young earth in the past and why some still do today. He explains that both scientific education and religious education are important in a civilized society. He personally believes that the God of the Bible created the universe and the physical processes driving physical and biological evolution — identifying himself as a theistic evolutionist. In explaining the genesis of Genesis, Skehan succinctly recounts St Augustine's reasoning, the external evidence for the biblical authors, the evidence from the Genesis document itself, varying traditions of scripture scholars, and how creationists differ from those in the mainstream of scriptural studies. The significant difference between creationists and most biblical scholars is the creationist belief that the Bible is to be taken literally and must not be interpreted by techniques used on other literary works.

A transition is then made to creationist attempts to determine the age of the earth from the Bible. Skehan explains how and why biblical scholarship and science have changed over the years, including sections on the age of the earth as calculated from the Bible, and the physical and biological data concerning the age and evolution of the earth.

The chapter ends by summarizing the creationists' ultimate position: if there is a conflict between science and a literal interpretation of the Bible, then science is wrong. Skehan explains how religious and scientific endeavors are two different kinds of knowledge, explaining that those who misrepresent the Bible as science, rather than a theological document, are damaging religion.

The reader quickly comes to understand that the reasons why creationist students believe what they do about evolution often has as much (or more) to do with biblical illiteracy or marginal literalist traditions than with misconceptions in science. Because of this problem, Skehan goes as far as to state:
The education of every science teacher who is likely to face the creation science mindset should include something about the premises and procedures of modern biblical scholarship (p 16-7).
class="RNCSE"> Probably everyone would wholeheartedly agree that it would benefit science teachers better to understand the reasons for their students' learning roadblocks, but encouraging future teachers to take biblical scholarship training to become public high school science teachers will be suspect by some — including many practicing science teachers. Yet it could be plausibly argued that because the history and philosophy of science has included brushes and entanglements (to say the least) with biblical scholarship, and because the history and philosophy of science should be integrated in science courses, the education of science teachers should therefore include some biblical scholarship. However, Skehan goes further and states that:
Teachers must be able to help students from varied backgrounds ... realize that there is no necessary conflict between interpretations of data from scientific studies and religious beliefs based on the Bible (p 2).
class="RNCSE"> This is a stimulating statement. Most people would probably have no problem with students' coming to an understanding that no conflict exists between science and the Bible as a by-product of public school education. However, many more people might take issue with preparing public school science teachers to be able to help students to realize that their religious tradition is erroneous (or at least part of their religious tradition is erroneous). It is a subtle distinction that can be an intriguing point of discussion for educators.

This first chapter is a concise, detail-rich history of some of the relevant issues concerning science and biblical scholarship, with a good relevant criticism of creationism woven throughout for instructors wanting better to understand the biblical beliefs that may underpin their students' concluding that the science of evolution is unsound — all in only 18 pages!

Nelson's chapter on effective strategies for teaching evolution is also to the point, with a great number of useful ideas and strategies packed in a short read. His recommendations are useful not only for teaching evolution to a variety of students but also for teaching many other controversial issues. He believes that most other major scientific theories, which may be less well understood by the public than evolution is, would be rejected even more widely if the public understood these theories well.

The chapter begins with a discussion of key pedagogical strategies with corresponding problems, emphasizing the fundamental role of "active learning". The results of empirical studies supporting the use of these strategies in college-level education are given to show the significant positive effects of active learning compared to using only traditional didactic pedagogy and passive learning practices. Nelson then turns his attention to problems that arise from traditional content and curricula, emphasizing that instructors can make considerable changes here also. Some problems addressed are: (a) in the rush to cover the material, teachers often present just the conclusions, leaving out the importance of science's evidence-based critical thinking; (b) too often teachers appear to present all topics in science as equally well supported (even though evolution is far more supported than many other accepted scientific concepts); and (c) words are often used in science education in a way contradictory to students' common usage.

Not all pedagogical problems arise from using traditional pedagogy and content; many arise from outside traditional pedagogy and content. Nelson addresses some of these problems, such as public controversies that usually rest on disagreements about consequences of the science. Employing a "rusty hand-grenade" as his key metaphor, Nelson effectively illustrates risk analysis in a manner understandable to virtually all students. The intended result is that students can rationally disagree on how strong the evidence must be to justify various decisions based on the trade-offs — as recognized by students. This examination of trade-offs and consequences is then considered in light of teaching evolution. Students who perceive they have much more to risk (for example, eternal salvation) may require a great deal more evidence of the soundness of evolution than those students who feel they have little to risk.

Before Nelson proceeds to more explicit juxtaposing of evolution and types of creation, he effectively cautions his science-teacher readers not to incorporate the religious consequence approaches if they feel uncomfortable. The tools that he gives for bridging false creation/evolution dichotomies are certainly useful in post-secondary education, but some may be problematic to implement in public high school science courses due to their religious nature. However, even if some teachers are uncomfortable with personally implementing such approaches, the material is important for all teachers to understand.

More strategies are given for matters arising from outside traditional pedagogy and content. The ubiquitous problem of students' wanting teachers just to tell them what to memorize is countered with three separate strategies: (a) teaching the "game" of science — and explaining why evolution is good science, (b) drawing a clear distinction between what science does and what religion does, and (c) focusing on humans — because most students are quite interested in the details of the evidence for human evolution, they will be more motivated to do the necessary work for higher-level understanding.

The chapter ends with a table of 21 evolution questions with brief answers from "quick creation" (sometimes including "gradual creation") and basic science, including lines of evidence and applications. The information from the table is to be used in a very understandable "Big Mac" metaphor for helping students to learn the wide variation in strength of support among different statements about evolution. Nelson claims the strategies in the chapter make teaching more inclusive, effective, and fun. I certainly agree.

About the Author(s): 
Brian Alters
McGill University
3700 McTavish Street
Montreal PQ H3A 1Y2 Canada
brian.alters@mcgill.ca

Review: The Ghost in the Universe

Reports of the National Center for Science Education
Volume: 
23
Year: 
2003
Issue: 
1
Date: 
January–February
Page(s): 
29–30
Reviewer: 
David Eller
This version might differ slightly from the print publication.
Work under Review
Title: 
The Ghost in the Universe: God in Light of Modern Science
Author(s): 
Taner Edis
Amherst (NY): Prometheus Books, 2002. 326 pages.
The French mathematician and scientist Laplace famously answered the question of why he left out any mention of God from his book on celestial physics with the words, "I have no need of that hypothesis." Edis’s book is a reaffirmation and extension of that answer, showing how there is in fact no ghost in the universe at all — no major conceptual or empirical problems that science has not solved or promised to solve without reference to any god(s).

The book is a wide-ranging discussion of issues both scientific and historical, from biological evolution to sacred texts and morality. He starts by asking the provocative question, Does God exist? While he remains respectful of religion, saying "we have a lot to learn from religion", he concludes that there are excellent reasons to disbelieve in God (a position known as positive atheism, as opposed to negative atheism, which merely claims that there are no good reasons to believe). Theistic scientists will find his secularism discomfiting, and avowed atheists will find his openness to religion frustrating, but his argument is worth setting aside one’s personal convictions.

The book contains nine chapters, of which two or three will most interest the strictly scientific reader. These chapters cover theological and philosophical notions of God, evolution, physics and cosmology, history and sacred texts, the historicity of Jesus, miracles, mysticism and the mind/brain problem, faith and reason, and morality. All of them are written for the informed generalist or layman, although a little scientific background helps. For the professional scientist, there is still enough insight and detail to make the discussion, especially outside of his or her own specialty, useful and engaging.

The chapters that bear most directly on science are the second and third, with relevant explorations in the seventh (mysticism) and eighth (reason). In the second chapter (evolution), there is a worthwhile examination of "intelligent design", with which all scientists need to be familiar. The third chapter (cosmology) naturally ranges over the Big Bang, quantum physics, and the so-called "anthropic principle" — another back-door theistic notion that scientists need to know about. The seventh (mysticism) reviews the "scientific" argument about mystical experiences and brain states, although without reference to Newburg and d’Aquili’s popular work on the subject. The eighth (reason and faith), which I might have placed earlier in the book, starts with a chilling quote from Martin Luther to the effect that reason is the greatest enemy of faith because it does not aid spiritual things. People who are looking to learn more about the nature of reason and the "postmodern" challenge to science (as little more than an opinion or a "worldview") would be well-served to spend some time there, but the Luther quote says everything that we need to hear about reason and its relation to faith. Reason is, to paraphrase Steven Weinberg, neither for nor against faith but profoundly disinterested in it.

For those who are interested in the more specifically religious subjects, the chapters on scripture, the historical Jesus, and so on are worth a look. Also, these "non-scientific" chapters help to advance Edis’s main thesis, which is not stated explicitly until well into the book: that if there is a "ghost in the universe", it is randomness and accident. The mistake theists make, he asserts, is that they misrepresent science as narrowly concerned with "law" and nature as narrowly characterized by "regularity", leaving a gap of creativity and order that can only be filled with intelligence and intention. Edis makes the point — and supports it with illustrations from nature, scripture, and history — that the universe is in fact a unique combination of the regular and the random, the lawful and the accidental. History is the fundamental theme: a world that has evolved to this particular state is "a deeply historical world. The evolution of the universe is constrained by the frozen accidents of the past, but novelties also keep arising from, again, accidents. Ours is not a world to be summed up in a few equations" (p 106). Thus, as Gould has said, if we rewound the "tape of time" and let it run again, it might run very differently.

Edis drives his point home well with his analyses of scripture and religious history. Not only natural laws but also social facts are the result of specific identifiable events and the crystallization and institutionalization of successes, failures, or pivotal decisions. While not advocating a "science of history" — one can no more sum up human history than natural history in a few equations — it does show that, with a few diverging events, the religious face of the world could have been very different, too.

If there is one shortcoming of Edis’s religious discussion, it is that he focuses exclusively on the Judaeo–Christian–Muslim complex of religions. He does mention Buddhism in the mysticism chapter, but other religions, including traditional, animistic, "non-theistic" religions, are completely absent. But fair-minded observers of religion cannot allow one religious view to hijack and dominate the "god-talk", nor can we assume that everyone who uses the word "god" even means the same thing by it. In the end, the best argument against God may not be science but all the other gods.

Ultimately, in his main thesis, Edis probably has his finger on the issue that will distinguish the science of the future from the science of the past and that will forever remove the "gaps" into which theists thrust their god(s). While science cannot prove that there are no gods, it can do what Edis, along with Weinberg and Laplace, have suggested it does: demonstrate that there are no "ghosts" in the universe at all — no need for any other hypotheses than the ones naturalistic science offers.

About the Author(s): 
David Eller
PO Box 22174
Denver CO 80222

Review: The Primate Fossil Record

Reports of the National Center for Science Education
Volume: 
23
Year: 
2003
Issue: 
1
Date: 
January–February
Page(s): 
45
Reviewer: 
W Eric Meikle, NCSE Outreach Coordinator
This version might differ slightly from the print publication.
Work under Review
Title: 
The Primate Fossil Record
Author(s): 
Walter C Hartwig, Editor
Cambridge: Cambridge University Press, 2002. 530 pages.
This is an admirable effort to provide a concentrated and uniform treatment of the fossil record of that mammalian order of primary interest to our ever-anthropocentric selves. New fossil discoveries related closely to human origins and ancestry tend to be well-publicized and receive wide popular attention. Every year at least one or two new hominin specimens, if not species, make headlines. The pace of such significant fossil discoveries has quickened throughout the last century, and especially in the last three decades.

Those who are not primate paleontologists, however, probably are not aware how closely this pattern of increasing knowledge about our Pliocene and Pleistocene hominin relatives is paralleled by an increasingly rich fossil record for the entire Primate order, covering more than 50 million years. Essentially all fossil primate groups are much better known today than they were in 1960, or even in 1980. However, no comprehensive reference work on this topic has been published in recent years. This book fills that gap, and will serve as a starting point for professionals and advanced students for years to come. While technical, expensive, and not intended for beginners, it does contain numerous illustrations and extensive references to the primary scientific literature, as well as discussions of interpretations and implications of this wealth of primate fossils.

About the Author(s): 
W Eric Meikle
Outreach Coordinator
National Center for Science Education
PO Box 9477
Oakland CA 94709-0477
meikle@ncseweb.org

Review: The Quest for Truth

Reports of the National Center for Science Education
Volume: 
23
Year: 
2003
Issue: 
1
Date: 
January–February
Page(s): 
41–43
Reviewer: 
Lawrence S Lerner, California State University, Long Beach
This version might differ slightly from the print publication.
Work under Review
Title: 
The Quest for Truth: Scientific Progress and Religious Beliefs
Author(s): 
Mano Singham
Bloomington (IN): Phi Delta Kappa Educational Foundation, 2000. 184 pages.
This is an interesting but perplexing book. The author, a fundamental-particle physicist at Case Western Reserve University, has been active in the effort to keep "intelligent design creationism" out of the Ohio science education standards. But creationism is only one of the factors — perhaps a minor one — that have motivated him to write this small book. Singham devotes most of the introduction to an outline of the conflict between science and three forms of creationism, which he felicitously dubs strong (6-days-plus-flood), weak (day-age), and superweak ("intelligent design") creationism. He then expands this discussion into a series of broader questions concerning the relationships and conflicts among what he dubs "elite science", "popular science", "elite religion", and "popular religion". But these questions lead the author to the use of such difficult terms as truth and objective reality. On reading beyond the introduction, it becomes clear that a discussion of the meaning of these terms lies at the center of his interest; the conflict between science and creationism seems to serve mainly as a segue into these broader and deeper matters. The author holds that his long digression is essential to further discussion of the science-religion conflict (and of creationism in particular). But aside from using creationist assertions as examples for some of his arguments, he never really provides a thorough discussion of this subject.

The middle and largest part of the book — 100 pages or so — is the most interesting and useful. The author attempts, with some success, to acquaint the nonspecialist reader with mainstream philosophical views of the nature of science. As one would expect, the discussion centers on the works of philosophers of science Karl Popper, Thomas Kuhn, Imre Lakatos, Paul Feyerabend, and Richard Rorty; by far the heaviest emphasis is placed on Kuhn's analysis of scientific revolutions (Kuhn 1996). Inevitably, as the author warns the reader, the discussion cannot be complete — only so much can be conveyed in a relatively brief summary.

"Truth", the key word in the title, is a slippery term. In theology, it has at least one clear meaning: What is revealed in sacred scriptures is by definition true, and theological argument can proceed on this sound foundation — at least among those theologians who share faith in that particular revelation. Science, however, does not have such a starting point. Popper stressed the now widely accepted view that science can never achieve truth but it can make and then test assertions that are falsifiable. If a theory survives numerous and varied attempts at falsification, one can have a degree of confidence in the reliability of that theory over a broad range of phenomena. Moreover, if a statement is inherently not falsifiable (for example, "God is just"), it cannot be a scientific statement.

If a scientific theory cannot be "true", can it at least be "correct"? Certainly, in the sense that it accounts for a range of phenomena with good accuracy and can be used to predict the outcome of previously unknown events. Scientists, in contrast to philosophers of science, do not worry too much about this point. Given a particular problem, it is usually pretty obvious to the skilled investigator which theory will yield a satisfactory solution.

How are the sciences related? Singham argues that most scientists are reductionists. Perhaps he is led to this view in part by the hyperbolic titles that famous particle physicists give to their writings aimed at a broader public — and particle physicists do love to use such names as "The Theory of Everything" to describe their work, sometimes only partly facetiously (Lederman and Teresi 1993; Weinberg 1994). If Singham were to consider the views of scientists other than his fellow particle physicists, he might well take a different position regarding the philosophical stance of most scientists. Moreover, the reductionist position he frames is idiosyncratic; he argues that physics deals with the smallest objects (subatomic entities), chemistry with larger molecules, and biology with large chemical systems. He therefore sets up a reductionist hierarchy that is strictly one of scale. He continues,
the smaller the size scale of the discipline, the closer to truth that discipline is judged to be. Thus, a complete understanding of particle physics would explain how protons, neutrons, and other nuclear particles are formed and how they interact to form nuclei. Since these form the constituents of nuclear physics, all of nuclear physics also would be explained. Similarly, once we know how atomic nuclei form and interact with other atomic components, we would have explained atomic physics and chemistry. … And once we have completely explained chemistry, then we also will have explained biology, then upward through the latter to society and the universe.
This is, I think, a straw-man description of reductionist epistemology too naïve to convince most scientists. It founders immediately on the rocks of emergent properties. There can be no doubt, for instance, that biological systems obey the rules of chemistry without exception. But the rules of chemistry could never have predicted a priori that genetic information is carried by DNA, or that the bases A, C, G, and T comprise the alphabet that conveys that information as it does. Similarly, a thorough knowledge of a deer as a biological organism will not furnish a basis for explanation of the complex herd behavior of the species to which it belongs.

Later, Singham digresses into a cogent and, I think, widely accepted criticism of the way science is taught at all levels below graduate school. He adopts the so-called constructivist view of education — the instructor should not simply assume that his students' preconceptions are wrong and then proceed to lecture them on the correct stuff, but should let them build on their own knowledge systems and arrive at the consensus of modern science through a process of adding new experience to what they already know. While I am sympathetic with this approach as a pedagogic technique, I do not see it as a basis for a philosophy of science. Moreover, I am not at all clear as to what the discussion of constructivist pedagogy contributes to the main argument of the book, except that it leads by inference to the view that pseudoscience has intrinsic intellectual value.

Singham finally comes to what I take to be his solution to the problems of public misconceptions of science and the conflict between science and religion. This solution lies in acceptance of the ideas that (a) all knowledge is valid and (b) science does not seek truth but control over the environment. In adopting this position, Singham comes close to abandoning the distinction between science and pseudoscience. As a corollary, he argues that the important court decisions that distinguish between creationism and science are not intellectually honest. Most scientists would maintain that, complex philosophical structures aside, it is not too difficult to distinguish between science and pseudoscience on the basis of straightforward criteria. In the same way, several courts have not found much difficulty in distinguishing between real science and religiously based programs disguised as science.

Singham further reconciles the Kuhnian concept of incommensurable paradigms (for example, Newtonian physics vis-à-vis quantum mechanics) by making an analogy with biological evolution. Just as species branch from pre-existing species — the metaphor is that of a proliferating shrub — new theories branch from pre-existing ones. In both cases, the process is contingent; if the pre-existing branching structure had been different, the new branching would have been, too. Singham argues further that this metaphor avoids the misconception that knowledge — at least, scientific knowledge — is finite and we will someday know everything there is to know about the universe. Rather, Singham's shrub branches out unendingly into the spaces available between and above the existing branches.

This metaphor is a pretty one and may satisfy many readers. My own view is that it is not very useful except for convincing those who are too much influenced by the idea of a Theory of Everything.

It is, I think unfortunately, never terribly clear how all this will solve the problem of widespread public belief in creationism and other pseudosciences. Nevertheless, the book is a good read and a good way for the educated but nonspecialized reader to approach both the current problems of the philosophy of science and its position in the scientific world.

References

Kuhn TS. The Structure of Scientific Revolutions. 3d ed. Chicago: University of Chicago Press, 1996.

Lederman L, Teresi D. The God Particle: If the Universe is the Answer, What is the Question? Boston: Houghton Mifflin, 1993.

Weinberg S. Dreams of a Final Theory. New York: Vintage, 1994.

About the Author(s): 
Lawrence S Lerner
lslerner@csulb.edu

Review: Trilobite! Eyewitness to Evolution

Reports of the National Center for Science Education
Volume: 
23
Year: 
2003
Issue: 
1
Date: 
January–February
Page(s): 
34–35
Reviewer: 
Kevin Padian, NCSE President
This version might differ slightly from the print publication.
Work under Review
Title: 
Trilobite! Eyewitness to Evolution
Author(s): 
Richard Fortey
New York: Alfred a Knopf, 2000. 287 + xiv pages, 16 plates.
Perhaps the title "Trilobite!" does not have quite the threatening ring of "Jaws!" or "Carnosaur!" (with or without the exclamation point), but the sub-title really gets to the meat of the book. The trilobites were eyewitnesses to evolution in many different ways. Richard Fortey, trilobite specialist at the Natural History Museum in London and a fine writer, is an ideal guide, not just for his expertise in the animals, but for his literate approach to the history of knowledge about trilobites and for his ability to use them to show how scientists approach evolutionary problems with fossils.

Fortey is the author of several excellent books, including Life, Fossils, the Key to the Past, and The Hidden Landscape. Far more than a taxonomic specialist, he has spent his career studying the importance of trilobites to major problems in evolution, including their relationships, their geographic spread and what this might say about correlating rocks from ancient ocean bottoms, and their morphological diversity and functions. Given the scope of his other books, it is not surprising that Fortey chose to introduce readers to his beloved fossils using a problem-centered approach (rather than a dry, taxonomic, textbook-like one). An especially pleasant added value is his penchant for literature, local history, and the development of the field with all its personalities, which allows the reader a vivid and close look at the science.

"Eyewitness" is an especially apt theme for the book. Fortey begins by taking us to a spot on the North Cornwall coast called Beeny Cliff. This is where Thomas Hardy famously situated a scene in his early novel A Pair of Blue Eyes that became the archetypal — and literal — cliff-hanger of Victorian prose. In the novel, Knight, one of the protagonists, slips and tumbles over the edge of the cliff. Clinging to his life, desperately waiting for aid, Knight comes face to face with a trilobite embedded in the rock, which stares at him with stony eyes dead for millions of years. Instead of seeing his life flashing before him, Knight, an amateur scientist, sees the history of life — from primordial slime to iguanodons and mammoths. It has been known for some years that Hardy cribbed the paleontological knowledge in this passage from one of Gideon Mantell's popular books of the time. Fortey reveals another twist to the cliff-hanger: there are no trilobites in that particular geologic section.

But the eyes of the trilobite that stared at Hardy's Knight are amazingly complex and varied structures, originally formed of calcite. Trilobites retained this ocular legacy through their evolutionary history, but found ways to modify the crystal structure and the number and size of the lenses. Recent technology has enabled scientists to model and simulate the structure of these eyes in order to understand just what trilobites saw and how the eyes evolved. They certainly witnessed a great deal of geologic history.

Trilobites are distributed all over the world, from the Cambrian to nearly the end of the Permian, roughly speaking the first 300 million years of the good fossil record that we call the Paleozoic Era. From their earliest appearance they are quite diverse, and they are notorious for their rapid rates of origination and extinction of species. This is borne out by Fortey's remark that even in the Early Cambrian, trilobite faunas are different from one another in different parts of the globe. As continental shelves separated and collided and moved all over the world, the trilobites kept pace. Like few other groups, they point geologists to rock strata that have similar faunas that reflect deposition at about the same time. This has helped tremendously in correlating and connecting ancient pieces of real estate into a cohesive history of geologic strata.

Fortey's book also covers the people who have been witness to the developing understanding of trilobites, which were first interpreted as odd flatfishes. He paints fine portraits of geologists and paleontologists who have braved rain, cold, and provincial cooking to search out these petrified beasts in the remotest places. Fortey recounts how knowledge of the trilobites expanded through time as better-preserved specimens revealed a fantastic diversity of eyes, legs, segments, and spines. And he explains how recent advances in developmental biology have revealed the probability that Hox genes underlay these variations, just as they do in living arthropods. One of Fortey's most interesting portraits, to me, was his account of the Cambrian "explosion" of trilobites and other invertebrates. Fortey cuts through a lot of the silliness about "phyla" and timing of diversification that seems to flummox creationists like Jonathan Wells and Phillip Johnson — neither of whom is conversant with the evidence.

Readers should not expect to find an omnibus reference book on trilobites. Fortey has a lot to teach about trilobite structure, diversity, and evolution, but his book is far less pedestrian and far more engaging than a more text-like treatment would have been. Rather, he has used trilobites as a vehicle to explain a great many aspects of evolution, geologic history, and how we know what we know about these ancient animals and the problems that they illuminate. Besides, his prose is genial and knowledgeable and his diction is superb. We in the field of evolution are lucky to have a great many fine writers, and Richard Fortey is one of the best.

A word of caution: Trilobites are among the most popular and available invertebrate fossils — in particularly a number of species from Morocco, some of which Fortey figures in his book with elaborate spines, horns, tails, and legs. But caveat emptor: commercial purveyors often "restore" the finer and more lucrative details, and your local fossil emporium might not know this (or tell you).

About the Author(s): 
Kevin Padian
President, NCSE
PO Box 9477
Berkeley CA 94709-0477

RNCSE 23 (2)

Reports of the National Center for Science Education
Volume: 
23
Issue: 
2
Year: 
2003
Date: 
March–April
Articles available online are listed below.

Paradigm Glossed: How to Make an ID Debate Worthwhile

Reports of the National Center for Science Education
Title: 
Paradigm Glossed: How to Make an ID Debate Worthwhile
Author(s): 
Clay Farris Naff and Jim Bechtel
Center for the Advancement of Rational Solutions
Volume: 
23
Issue: 
2
Year: 
2002
Date: 
March–April
Page(s): 
7-8
This version might differ slightly from the print publication.
The firefly (Photuris pyralis) is a wonder of nature. Its tiny body contains luciferin and luciferase, two rare chemicals that scientists have been unable to synthesize. Yet, as any child who has grabbed one of the slow-flying insects on a summer evening knows, those substances produce a remarkable and beautiful phenomenon: cold light.

Curiously, Photuris pyralis never came up in the Great “Intelligent Design” Debate held at winter’s end at Saint Paul United Methodist Church of Lincoln, Nebraska. Yet, somehow, the debaters — philosopher Paul Nelson of the Discovery Institute and evolutionary biologist Massimo Pigliucci of the University of Tennessee — managed to mimic the firefly’s trick: they cast much light with little heat.

Over the span of nearly two hours, they offered arcane details of biology and earthy, sometimes humorous presentations of their arguments. In the end, they inspired the Center for the Advancement of Rational Solutions (CARS) to consider new ways of resolving the public policy impasse over the science curriculum.

Considering the unsavory history of creationism/evolution debates, this amounts in our view to a minor triumph. And yet nothing miraculous took place. On the contrary, we believe what transpired in Lincoln could be replicated — with variations — around the country. To that end, we would like to share the story of our event and insights about what made it work. The debate centered on the question: “Is ‘intelligent design’ a valid scientific alternative to evolution?” At the start the audience of some 150 people who braved a blizzard to attend were told that although this was to be a debate, “the only winner will be those of you who are willing to consider a point of view or information you haven’t thought about before.”

That position was in keeping with our group’s outlook. Although the leadership of CARS is solidly in the evolutionary camp, the organization exists to promote rational reconciliation of religions with science and with each other. Its membership includes a variety of creationists, from biblical literalists to nonspecific ID advocates, whose views are welcomed within the group’s discussions.

Talking Points

The debate opened with PowerPoint presentations from each side. Nelson, who holds a doctorate in philosophy from the University of Chicago, surprised many by conceding from the start that, strictly speaking, “intelligent design” is not a valid scientific alternative to evolution — at least not yet. “Intelligent design”, he admitted, has yet to demonstrate its validity or to be accepted by the majority of the world’s scientists. However, he argued, the really fruitful questions concern the nature of science. Its commitment to methodological naturalism, Nelson said, “leaves you with only that one tool in your kit.” Science would be “more honest” without this unnecessarily restrictive rule, he said.

Nelson introduced one of ID’s two main arguments with a humorous anecdote about “Mint Jelly Ridge”, a con man who faked injuries by pretending to slip on mint jelly in restaurants throughout the Midwest. Insurance companies who paid claims on behalf of restaurant owners detected a pattern that indicated design rather than accident, leading to Ridge’s arrest and conviction. This, Nelson said, was an example of the design inference, something routinely used in forensics and a method that Nelson’s Discovery Institute colleague William Dembski claims should be applied to features of nature.

In his presentation, Pigliucci offered a definition of biological evolution as both change in the frequency of genes and, historically, as the descent of species from common ancestors along the “tree of life”. He took pains to exclude the origin of life from evolutionary theory. Pigliucci defended evolution on the grounds that it offers a coherent explanation for our observations of biological diversity, and it makes predictions that can be empirically tested.

In contrast, he said, “intelligent design” offers only flawed arguments with no predictive value. Taking on one of these — Michael Behe’s argument for the “irreducible complexity” of certain microbiological features — Pigliucci said that it amounts to an “argument from ignorance”. If something cannot be explained by evolution at present, he said, some would have us believe that it must have been intelligently designed. Such a strategy, however, consistently fails as science progresses, he argued.

By the same token, “intelligent design” advocates should be prepared to explain numerous instances of poor design in nature, Pigliucci asserted. He offered the example of rabbits that depend on certain bacteria in their guts to supply necessary digestive enzymes. Unfortunately, Pigliucci said, the rabbits have no means to pass on the bacteria except by having baby rabbits eat their mother’s feces. He added that biological relatives of rabbits do have genes that produce the enzyme directly, so evolutionary theory would predict that remnants of the genes still exist in the rabbit, and, sure enough, Pigliucci said, the pseudogenes have been found.

Give and take

Up to this point, the arguments would have been familiar to anyone acquainted with ID–evolution disputes. Things got more interesting, however, when the debate moved into its free-flowing discussion phase. Nelson raised “Clarke’s Law” , the acclaimed science-fiction writer’s dictum that any sufficiently advanced technology would appear to be magic to a less advanced civilization. He asked Pigliucci how Aristotle would have explained a television remote control. His opponent responded that Aristotle would have assumed a naturalistic explanation: a supernatural explanation cannot be tested, he said. Nelson responded by musing on whether “supernatural” remains a useful category. Perhaps it is time to move beyond that concept and make testable predictions outside the bounds of naturalism, he suggested.

Later, Nelson raised a possibility for a specific ID prediction. Referring to “orphan genes” occurring uniquely in some microorganisms without analogs in related species, he said that ID advocates should be prepared to predict that similar anomalous genes will be found scattered throughout the zoological realm. He also pointed to the origin of life as a focus for ID. Reasoning that RNA could not have held together long enough to give rise to life, Nelson speculated that the fragility of RNA could be a “signature” of the intelligent designer. Pigliucci replied that the frequency of “orphan genes” is well within the limits of random phenomena, and that RNA’s fragility might have been solved by the “pizza model” of biogenesis, in which organic chemicals are thought to have self-assembled within stable films on rocks.

Self-critique

Most interestingly, each debater offered an unsolicited criticism of his own side. Pigliucci denounced “scientism” — the claim that science can eventually answer all questions — as indefensible arrogance. Nelson declared that teaching “intelligent design” in science classes would be wrong at this stage. Philosophy courses are the proper venue for the study of ID, he added, until it proves itself scientifically valid. This willingness to be self-critical and to trust in the civility of the other side contributed greatly to the thoughtful atmosphere. To be sure, there were skeptical and even emotional reactions from audience members during the question-and-answer segment that closed out the debate. But on the whole, it was a refreshingly high-minded occasion.

The lion’s share of credit goes to the debaters themselves, who eschewed rhetorical tricks, distractions, and combativeness in favor of a serious, accessible consideration of the issues. Still, the structure and sponsorship of the debate undoubtedly helped. Putting the focus on “intelligent design” helped to prevent the debate from becoming a mere rehearsal of attacks on evolution (not that Nelson would necessarily have conducted himself that way).

Response to the debate was uniformly positive across the ideological spectrum. At the request of members, the next meeting of our organization was devoted to follow-up discussion. Three members requested time to offer brief prepared presentations. Two were defenses of evolution, while the other was a defense of “intelligent design” and a call for opening up the public school science curriculum to alternatives on the grounds of democracy.

Interestingly, in the ensuing discussion, considerable support emerged for the idea of teaching “intelligent design” — but not in science classes. Rather, there appeared to be support in the group for the idea of introducing philosophy of science and religion classes into the public school curricula alongside regular science classes. With appropriate safeguards on neutrality concerning religion, this might represent an avenue to reconciliation, with the added benefit of exposing students to philosophical discourse and critical thinking at the high school level.

Call it the firefly option.

About the Author(s): 
Clay Farris Naff and Jim Bechtel
Center for the Advancement of Rational Solutions (CARS)
649 S 18th Street, #31
Lincoln NE 68508

Review: In Darwin's Shadow

Reports of the National Center for Science Education
Volume: 
23
Year: 
2003
Issue: 
2
Date: 
March–April
Page(s): 
36–37
Reviewer: 
Aubrey Manning
This version might differ slightly from the print publication.
Work under Review
Title: 
In Darwin's Shadow: The Life and Science of Alfred Russel Wallace
Author(s): 
Michael Shermer
New York: Oxford University Press, 2002. 422 pages.
Opening this book, I had a quibble about its title. Is Alfred Russel Wallace really such an unfamiliar figure today? Was he seen by his contemporaries as overshadowed by the great man? I am not sure. Indeed, Shermer’s account of his later life reveals how much Wallace stood out then — he became recognized, at least in Britain, as “the last of the Great Victorians”. In part this was a result of his remarkable longevity, for he lived on to the age of 90 (until the end of 1913). Remarkable is the right term because during his extended expeditions to the Amazon and the Malay archipelago (modern Indonesia), he was frequently brought to death’s door by malaria, yellow fever, and many other tropical plagues. He must have had the constitution of the proverbial ox!

This is a distinguished and scholarly biography with excellent coverage of the science. Shermer is concerned with the history of evolutionary ideas and uses the interaction between Wallace, Darwin, and others to great effect. He goes beyond this to examine the extraordinary range of Wallace’s interests and how they came to dominate different stages of his life. It is always clear and attractively written but is very detailed in places and probably not best suited for non-specialists wanting an introduction to Wallace’s life. They might first go to Peter Raby’s very good Alfred Russel Wallace: A Life (Princeton: Princeton University Press, 2001; reviewed by John Wilkins in RNCSE 2003 Jan/Feb; 23 [1]: 39–40), but it is to Shermer one must go to dig deeper.

Wallace had little of Darwin’s science background in his family nor the privileges of money. He was eighth-born into a family that never had much to spare. He had little formal education but considerable opportunity for reading and inquiry. He had quickly to earn a living and did a little teaching, then spent a few years as a surveyor working for the burgeoning railway companies. In view of what came later, it is interesting to note that very early on he came to abandon conventional religions as poorly equipped to explain the phenomena of nature. Also, he and a brother attended evening classes in one of the “mechanics’ institutes” where working people could learn science and some philosophy. Wallace was here introduced to the socialist ideals of Robert Owen, the founder of New Lanark. But from his earliest days he loved an outdoor life; he was captivated by the natural world and became a very acute observer. He met up with HW Bates, a young man of very similar tastes, and together they planned a major expedition to the Amazon basin, to be financed entirely from the collections they would make. This set the form of all Wallace’s early career: his fascination with the variety of life provided his delight, his intellectual challenge, and his livelihood!

He was quite early in correspondence in Darwin, who recognized that the revelation of the huge variety of species Wallace was describing from the tropics and their geographical distribution were of great significance. Indeed, they began to throw some light on “that mystery of mysteries”, as Darwin described the origin of species in the introduction to his crucial volume. It was clear that Wallace himself was musing on that mystery, and Darwin probably knew this. Then came the bombshell of a letter he received in June 1858 sent from the remote East Indies. Wallace there set out ideas on natural selection and its operation virtually identical to those which Darwin had been painstakingly developing over the 20 years since he returned from the voyage of the Beagle.

The story of how Darwin and Wallace came to publish a joint paper in that year and how Darwin subsequently accelerated into action over the Origin is now fairly familiar. It has aroused bitter accusations of plagiarism from those — and there are always iconoclasts among us — who accuse Darwin of deception at Wallace’s expense. Shermer provides here a most detailed and sensitive analysis of those crucial months and all that has been written about them. He totally acquits Darwin, clearly believing that he was basically a nice person, and I totally agree with him! Darwin often acknowledges the extent of Wallace’s contribution, particularly in relation to the geographical distribution of animals and plants, which lent powerful support to evolutionary ideas. There is certainly no sign that Wallace ever felt a trace of resentment. He obviously admired Darwin and throughout his long life continued to refer to him and promote the concept of natural selection. He remained extraordinarily modest and self-effacing about his achievements. It was quite a struggle for his colleagues to get him to accept election to the Royal Society of London, for example.

Wallace’s one departure from Darwin and from the power of natural selection concerned the human brain, which he believed forced him to accept a designing force beyond nature. Why else would “savages” be already in possession of a brain identical to that of the more civilized when only the latter uses its amazing capacities to the full extent? Alas and alas, I feel! How could Wallace, who was such an acute observer, not recognize the scope of the civilizations around him as he moved through the Malay archipelago? But then even the greatest people have blind spots. Darwin remained convinced that natural selection was behind it all, but even he found it hard to credit that he was from the same species as the natives of Tierra del Fuego!

Certainly Wallace pursued various potty ideas such as spiritualism in the latter part of his life. He clearly lacked judgment in some cases; Shermer relates the comic story of Wallace’s attempt to win 500 pounds (which he probably needed — he was never flush with funds!) from a wager offered by a lunatic who believed the earth was flat. Careful measurements were made along a 6-mile, dead-straight stretch of canal. The curvature was clear, but no money was forthcoming, nothing but a stream of insulting and threatening correspondence and bills from lawyers.

Nevertheless, Wallace was also seriously involved with the betterment of human societies and retained his youthful allegiance to socialist ideals. He was extraordinarily productive on a variety of issues. What other biologist would have contributed books on Land Nationalisation and Social Environment and Moral Progress among all the extensive biological work! Shermer provides a full bibliography of Wallace, which in itself is a remarkable record of a remarkable and admirable man. The book is well-illustrated and includes some delightful photographs of Wallace as an old man. There is one of him, near the end of his long life, resting on the ground in the sunlight of a woodland path, still delighting in the natural world. It is one of many images from this excellent biography I wish to retain.

About the Author(s): 
Aubrey Manning
ICAPB
Ashworth Labs
West Mains Road
Edinburgh EH9 3JT
United Kingdom

Review: Species of Origins

Reports of the National Center for Science Education
Volume: 
23
Year: 
2003
Issue: 
2
Date: 
March–April
Page(s): 
36–37
Reviewer: 
George E Webb, Tennessee Tech University
This version might differ slightly from the print publication.
Work under Review
Title: 
Species of Origins: America's Search for a Creation Story
Author(s): 
Karl W Giberson and Donald A Yerxa
Lanham (MD): Rowman & Littlefield Publishers, Inc, 2002. 277 pages.
The continuing controversy over the teaching of evolution in the public schools has undergone various transformations during the last century. From the post-World War I campaign of William Jennings Bryan through the creation science movement of Henry Morris to the "intelligent design" efforts associated with Phillip E Johnson, opposition to the inclusion of evolutionary concepts in the science curriculum has remained a constant in recent American history. Emphasizing the constancy of anti-evolution sentiment, however, can lead to the conclusion that a monolithic movement seeks to remove Darwin from the public schools. A closer analysis reveals a far more complex situation.

The authors of Species of Origins (one a physicist, the other a historian) provide an overview of the various ideas behind the evolution/creation debate in the United States in an effort to clarify our understanding of this long-standing controversy. Following an introduction in which they stress their goal of a fair and balanced treatment of the various creation explanations (thus, species of origins), they provide a brief overview of the evolutionary explanation accepted by the scientific community. Specialists in the various disciplines they survey will, to be sure, blanch at the authors' discussions of such complex topics as the physics associated with the immediate aftermath of the Big Bang and the origin of life on earth, but the non-specialist will at least be exposed to important concepts. The authors end this chapter by emphasizing that despite the widespread acceptance of the evolutionary account by scientists, opinion polls consistently indicate that the public largely rejects this explanation.

Once the dichotomy between the scientific and public perspectives on origins is identified, they take the logical next step and rigorously analyze the different explanations offered by opponents to evolution. In an extensive and well-informed discussion of the creation science movement of Henry Morris and his colleagues, they emphasize that this version of anti-evolution sentiment must be examined within the scientific, religious, and social contexts of the movement. The literalistic reading of the Bible and the deeply-held concern about the decay of traditional morality are as important to the creation science perspective as is its focus on a 6-day creation and a global flood. The authors provide a carefully crafted discussion of all 3 contexts and are especially effective in describing the scientific arguments used by these creationists.

The authors make clear, however, that religious aspects dominate creation science. The importance of religion to creation scientists is in stark contrast to the situation among natural scientists, at least among those most active in the popularization of the evolutionary world view. In an intriguing chapter, the authors discuss the work of several popularizers, including Richard Dawkins, Steven Weinberg, Stephen Jay Gould, and others. Although they emphasize that a wide range of attitudes toward the science/religion clash exists among such popularizers, the authors conclude that traditional religion has no role to play in the popularizers' perspectives. The overt atheism of Dawkins is countered by the sense of loss Weinberg expresses over the lack of purpose in modern views of the universe, but persons of faith often find no significant difference between the two views. Gould's suggestion that science and religion work best when each restricts its focus to its own separate sphere works no better. The scientific sphere is concerned with facts, in his view, while the religious sphere is concerned with ethics and morality. To suggest that religion has nothing to do with "truth" is hardly a concept likely to attract support from the religious community.

Is there a middle path? The authors devote the remainder of their book to an examination of possible alternate explanations that would maintain both scientific and religious integrity. Such concepts as the gap and day/age models of creationism (rejected by Morris and his followers), as well as various versions of theistic evolution, are all described in sufficient detail to show the reader how complex the middle way might be. In the same category is the most recent of anti-evolution efforts, the "intelligent design" movement. The authors devote the last two chapters to this concept and its reception, providing a sound overview of the ideas involved in this latest challenge to Darwin.

The great strength of this book rests in the authors' decision to take the continuing evolution/creation debate seriously. They thus accept that any study of this topic must take the various components of the debate seriously, as well. Readers who want a balanced account of the various modes of anti-evolution sentiment of the past half century will find in Species of Origins a valuable introduction to an intriguing cultural phenomenon.

But is it possible that the authors have taken these anti-evolution views too seriously?

In their introduction, the authors acknowledge that they have accepted the postmodern view of the supposed clash between science and religion and have embraced the "methodological agnosticism" (p 10) of historian Ronald L Numbers in an effort to provide a more accurate view of the debate. Such earlier concepts as a "warfare" between science and religion have largely been abandoned by historians of science, who now stress that the relation between the two throughout history has been much more complex than the earlier metaphors implied. Thus, creating a dichotomy between the "progressive" world of science and the "reactionary" world of religion is both inaccurate and counterproductive. Far better, the authors emphasize, to treat the creationists with the same intellectual respect as the scientists.

This is an admirable goal, to be sure, but it guides the authors into the postmodern muddle of the "science studies" perspective, in which the concept of an accurate portrayal of nature is an illusion. Consider the subtitle of this volume: "America's Search for a Creation Story [emphasis added]". The chapter in which they summarize the modern scientific explanation of origins carries the title, "The Modern Creation Story [emphasis added]". The authors emphasize frequently the need for a creation "story" for all cultures, ancient and modern, and stress that the current debate shows that such a need continues in the early 21st century. Thus, American society seeks a "story" that will satisfy a deeply rooted cultural need.

The difficulty, of course, comes when there are two competing stories, one of which is largely based on a religious world view and the other largely based on a naturalistic world view. To determine which is "right", one needs to be able to evaluate the evidence presented in support. Is such evaluation taking place in contemporary America? If so, the question posed early in the authors' discussion takes on added significance: Why is it that most Americans reject the scientific explanation of origins?

The answer is embedded in the postmodern perspective the authors embrace. It is another example of the contemporary rejection of expertise that has increasingly guided discourse and decision-making over the last few decades. If we are dealing with different "stories", then does that not suggest that all "stories" are more-or-less acceptable? Or do we appeal to an "authority" who might have special expertise? This latter solution seems to be absent from non-evolutionary explanations of origins. Phillip E Johnson, the acknowledged founder of the "intelligent design" movement, plays a major role in the authors' discussion of contemporary anti-evolution sentiment. His credentials for offering a challenge to evolutionary explanations include his status as "a brilliant Berkeley law professor" (p 198), his academic position as "a recognized authority in criminal law and a tenured professor at Boalt Hall, the prestigious law school of the University of California at Berkeley" (p 200), and his ability to read popularizations of evolutionary theory "carefully through the eyes of a lawyer" (p 200). The publication data of most of the authors' cited references concerning anti-evolutionary ideas include the names of very few major publishers; most of these works have been published by religious publishing houses or in journals outside the academic mainstream. In short, those who seem to be the leading figures in the anti-evolution campaign (whether in creation science or "intelligent design") rarely have the background one would expect from individuals who are challenging one of the best established scientific concepts of the contemporary world.

Despite the authors' careful and balanced discussion of the various modes of thought concerning creation, in the final analysis their "story" suffers from a willingness to accept that scientists have no privileged position in crafting explanations of the natural world. A lawyer and a biologist are on equal footing when they attempt to offer explanations of the origin and development of life on earth. Surely, such a perspective carries the concept of "fairness" well beyond its proper role.

About the Author(s): 
George E Webb
Department of History
Tennessee Tech University
Cookeville TN 38505

Strategies to Help Students Change Naive Alternative Conceptions about Evolution and Natural Selection

Reports of the National Center for Science Education
Title: 
Strategies to Help Students Change Naive Alternative Conceptions about Evolution and Natural Selection
Author(s): 
Marshall D Sundberg
Emporia State University
Volume: 
23
Issue: 
2
Year: 
2003
Date: 
March–April
This version might differ slightly from the print publication.
[S]tudents’ initial qualitative, common sense beliefs ... have a large effect on performance ... but conventional instruction induces only a small change in those beliefs ... the basic knowledge gain under conventional instruction is essentially independent of the instructor (Halloun and Hestenes 1998).
This statement summarizes the outcomes of numerous studies on student learning that suggest a change in teaching methodology is critical to achieving a greater degree of scientific literacy among our students (Hake 2000; Mintzes and others 1998; Udovic and others 2002). Although this statement is a recognition of the constructivist philosophy of learning, it also acknowledges a more specific problem relating to many basic scientific concepts. For biologists, the most notable among these are evolution and particularly natural selection. Students bring many naive beliefs about evolution to the classroom, which are particularly resistant to change through traditional instruction (Sundberg 1997).

The purpose of my ongoing research in biological education is to identify and describe teaching strategies that are effective against such entrenched beliefs and that will promote a more sophisticated understanding of basic concepts. In this paper, I summarize the results of my most successful interventions to address (1) major concepts related to evolutionary theory and (2) concepts related to the nature of science.

The Course

Most of the investigative exercises described below have been used in an independent college introductory biology laboratory course, paired with a traditional lecture, but the greatest student gains were observed when “lecture” and laboratory were integrated into a single course. Students were a mix of biology majors and non-majors. The course was scheduled for two 3-hour blocks per week. This intensive block format allowed for great flexibility in varying the time commitment to a variety of pedagogical techniques and particular concepts. Five readings were used in lieu of a textbook: Lives of a Cell (Thomas 1974), The Cartoon Guide to Genetics (Gonick and Wheelis 1991), Darwin for Beginners (Miller and van Loon 1982), Ever Since Darwin (Gould 1977), and Ecological Vignettes (Odom 1998). A variety of “majors’” textbooks was also available for use in class or for checkout for use as an encyclopedic reference as needed.

The primary instructional technique was a Socratic dialog based on daily readings. These discussions were also used to introduce specific problems for laboratory investigation. For instance, Darwin’s response to tropical diversity in the Amazon is used as a lead-in to the investigation on variation. The technique of concept mapping (Novak and Gowin 1984) is introduced early, primarily as a tool to identify questions for investigation. In a completed concept map, virtually every connector between concepts identifies a testable hypothesis. The class is divided into research teams the first day; these teams collaborate on investigations throughout the semester. Considerable peer instruction takes place during the performance of investigations and as results are reported to the class.

Controls for this study included traditional majors’ lecture and laboratory, traditional non-majors’ lecture and laboratory, traditional majors’ lecture and investigative laboratory, and traditional non-majors’ lecture and investigative laboratory.

The investigations dealing with evolution began with a passage from an 18th-century evolutionist’s theory of evolution (Lamarck 1809, in Ames and Siegelman 1966: 28–9). I purposely chose Lamarck as an entry into the theory of evolution because most beginning students who express any belief in evolution actually have a Lamarckian understanding of the process. This is a starting point to which students can relate but which ultimately leads to results that students must reject. In this passage, Lamarck contrasts his theory with the dogma of special creation. Students read the passage, underlining key words and phrases. As a class we then construct a concept map of Lamarck’s theory and identify possible points of testing. Figure 1 is a simple concept map of our current understanding, with the three concepts identified by Lamarck in boldface. These three concepts are the focus of investigation.

Figure 1. Concept map of evolutionary theory with concepts identified from Lamarck reading in boldface

Variation

The null hypothesis, based on Lamarck’s text, is that species tend to be perfectly adapted to their particular circumstances, so there should be no significant variation among them in observable features. I present the research teams with a tin of either pecan fruits or sunflower seeds and challenge them to design an experiment to test the null hypothesis. Each team must formulate a research plan and have it approved before beginning the experiment. A variety of measuring instruments is available in the laboratory, including metric rulers, vernier calipers, graduated cylinders, and balances. (Students are familiar with each of these tools from their earlier investigation of accuracy and precision in measurement and basic descriptive statistics.) Typical parameters chosen for investigation include length, width (there are several sampling questions here such as where to measure, whether to choose maximum or minimum, and so on), mass, volume, and color pattern. Research teams must graph and interpret their data.

Figure 2. Summary student data of variation in seed length and seed mass
Figure 2 summarizes data from two student groups, one measuring seed length and the other seed mass. For comparison, the data are standardized into size classes. These data are representative of typical student results and were chosen to show two very different, yet common, patterns that students will discover. In both instances, evidence of variation in the chosen character is measurable and distinct. In the case of length, variation approximates a normal distribution, with the majority of individuals found in size class four. Similar distributions generally occur for width and volume. Seed mass exhibits more variability and in this case is almost evenly distributed among the size classes. Color pattern in sunflower seeds would be similar.

Several questions typically arise as individual research teams present and discuss their data. For instance, given the data discussed above, teams may question whether the observed variation is significant. Some may argue that the observed variation in length is so small as to be unimportant, and thus the data do not falsify Lamarck’s theory. This provides an opportunity for introducing the idea of a statistical test of an evolutionary hypothesis. Another common question concerns the presence or absence of what might seem a plausible correlation. In the above example, most students expect that longer seeds (or seeds of greater volume) would necessarily have greater mass. Here is evidence that what seems plausible is not always substantiated by data. Other unknown factors, in this case degree of hydration, may influence the data. These data can also be used to introduce the idea that the variation on which natural selection will work is random and does not arise to meet a specific need or purpose. Importantly, the variation investigation is simple and can be completed in one class period. A general characteristic of effective strategies for modifying ingrained misconceptions is that the tasks have simple manipulations and are of short duration (Sundberg and Moncada 1994).

Selection

Selection of existing characters is a key component of evolutionary theory; the testable null hypothesis is that the frequency of a specific trait in a population cannot be altered in subsequent generations by selection. For this investigation, we use two populations of fruit flies (Drosophila melanogaster) — wild-type “fliers” and vestigial-winged “crawlers”. After the class has had an opportunity to examine individuals of both populations, the research teams are divided into two groups. The teams in one group are challenged to test if the wild-type phenotype can be selected for; the other teams will attempt to select for the vestigial-winged phenotype. Although two or more teams are faced with the same challenge, each team must design its own experiment and have it approved before it can proceed. In the laboratory, I provide fly populations, flynap (used to anesthetize the flies), fly medium, and 2-liter plastic bottles. Each research team must provide any other additional materials it will need for its experiment. Typical materials include threads to suspend small containers of medium, straws, double-sided tape, flypaper, water moats, petroleum jelly, and external light sources.

Teams typically begin by introducing equal numbers of male and female flies of both phenotypes into their experimental and control chambers. (Most of the bottles can be hung in the room for decoration once they are set up.) During subsequent class periods, teams examine and take notes on the flies in their bottles. Although differential mortality can often be observed quite quickly, the experiments are allowed to run until the flies have produced at least their first generation of offspring.

Table 1
Sample Student Data for Fruit Fly Selection

None (control)For FliersFor Crawlers
FlierCrawlerFlierCrawlerFlierCrawler
Start101010101010
End15838245788123
Caught in Flypaper624

Table 1. Summary student data of selection for wild-type (flier) and vestigial-winged (crawler) fruit flies.

Table 1 illustrates typical results, from which we draw several important conclusions. The wild-type group is usually pleased by its success in selecting for fliers; selection can alter the frequency of a trait in later generations. But when challenged, these students realize that a significant number of vestigial-winged flies also reproduced. Under these conditions, the fliers were more likely to survive and reproduce, but the selection pressure was not so intense as to prevent vestigial-winged flies from reproducing, too.

Selection for vestigial-winged flies is usually less successful. Invariably there will be more flier offspring (which were selected against) than crawler offspring (which were selected for). The obvious explanation for students is that these teams were not successful in designing traps or obstacles that could effectively keep fliers from reaching a food source while permitting crawlers to feed. But these results, along with the control, also can be used to make the point that things are not always as simple as they seem. In fact, this provides the lead-in to a section on genetics. After studying Mendelian genetics, students are asked to re-analyze their fly data to see whether there might be some alternative explanations for their results. For instance, could a crawler mate with a flier? If so, what would be the phenotype of their offspring?

Adaptation and Heritability

These concepts also appear on the students’ concept maps of Lamarck’s theory. The null hypotheses are that organisms will not exhibit adaptation to environmental perturbation and that even if adaptions are evident, they will not be heritable. Perhaps the most common misconception about the mechanism of evolution is that individually acquired adaptations can be passed on to offspring. Therefore, this investigation is critical in helping students to develop a more sophisticated understanding of natural selection.

Research teams are provided with seeds of Wisconsin Fast PlantsTM and asked to design an experiment to test the hypothesis concerning adaptation to the environment. Fast PlantsTM are a particularly useful organism for this study because of the variety of characters that can easily be quantified: for example, number and size of leaves, number and size of internodes, overall length, and a variety of anatomical surface features such as hairs and stomata that can be sampled non-destructively. In addition, a variety of environmental treatments can be employed without concern for pain to the organism. Plants show much greater developmental plasticity in response to environmental factors than do animals. Finally, the life cycle is rapid enough that the treated generation can produce seeds that can be grown out in a second generation to test for heritability.

We usually begin by listing on the board as many environmental parameters as possible that might affect plant growth. Research teams are then asked to choose one parameter and design an appropriate experiment to test for an adaptive response. Variables involving light and water are the most commonly chosen, including light intensity, light quality (color), light duration, quantity of water applied, and substances added to water. Each team must investigate a different parameter and all research plans must be approved before the investigation can begin.

One of the more interesting student-designed experiments investigated the effect of gravity on stem growth. In this investigation, Fast PlantsTM were grown in square styrofoam cubes that can easily be laid on their side; the experimental cubes were placed on their side as soon as plants germinated — a period of about 3 days. Every day thereafter, the cubes were rotated to the next side so that, at the end of a week, there was a full rotation. The plantlets developed with a “corkscrew” phenotype. The controls were grown in the upright position.

Table 2A
Sample Student Data for Spiral Phenotype
Original "Treated" Generation

TreatmentDay 2Day 4Day 6Day 8
Upright Plants0000
Plants Rotated on Side0246

Table 2B
Sample Student Data for Spiral Phenotype
Offspring Generation - Grown Upright Only

TreatmentDay 2Day 4Day 6Day 8
Offspring of Upright0000
Offspring of Rotated0000

Table 2. Summary student data of heritability of adaptation to an environmental factor

The results of this experiment are shown in Table 2. The number of leaves produced in a spiral gyre were counted as “spiral revolutions”. Under optimal conditions, approximately one leaf is produced per day and thus each new leaf produced when a plant is oriented horizontally will be in a spiral gyre. The null hypothesis — that there is no phenotypic effect from the changing orientation to the force of gravity — must be rejected because of the obvious response of the plant to its horizontal rotation.

This was a particularly interesting experiment because a complex phenotype was produced that mimics the growth pattern of certain horticultural varieties such as the corkscrew willow. However, this adaptation cannot be inherited. Seeds from the treated plants, when grown in “normal” position, retain the normal upright growth pattern. Individual adaptation to the environment is not natural selection! Individuals can alter their form or behavior, to a limited degree, in response to their environment, but they cannot change their inherited characteristics.

Assessment of Effectiveness

The assessment items used in this study are drawn from instruments used in previous work (Sundberg 1997; Sundberg and Dini 1993; Sundberg and others 1994; Sundberg and Moncada 1994). To standardize the results, only scores on identical items, specifically targeted to common and persistent misconceptions, are reported here. The Integrative/Investigative category represents 3 pooled sections; the Majors’ Investigative Lab/Traditional Lecture category represents 4 pooled sections; and all other categories represent pools of more than 10 sections. In the previous work cited above, majors’ pre-test scores tended to be slightly higher than those of non-majors, but these differences were not significant. This pattern continues to hold true.

There is a consistent tendency for investigative instruction, integrating lecture and laboratory, to be more successful in promoting student understanding of the nature of science and the theory of evolution than traditional lecture/laboratory or traditional lecture/investigative laboratory. Figure 3 illustrates scores on a content post-test given at the end of the semester. Pre-test scores were in the range of traditional lecture/laboratory post-test scores. Virtually no change was observed in these classes between pre-test and post-test scores. In all four categories examined, the highest scores were attained when student-active lecture and laboratory activities were integrated in their presentation. Similarly, scores for traditional lecture and laboratory were the lowest; there was not a consistent difference between majors and non-majors courses. Students in traditional lecture courses combined with investigative laboratories obtained intermediate scores, and again there was not a consistent difference between majors and non-majors. Although similar tendencies are clear with each concept, the only statistically significant gain over the traditional approach was found in the category of improving scientific literacy.

Figure 3. Impact of teaching style on student learning (percent correct on content post-test) in four concept areas: Scientific Literacy, Variation, Heritability, and Natural Selection.

It is also clear from the data that some misconceptions are more ingrained than others. In particular, misconceptions concerning natural selection are particularly resistant to instructional intervention. Scores in this category were the lowest and showed the least change between pre-test and post-test scores. Scores in heritability, directly related to Mendelian genetics, consistently showed the greatest gains.

Figure 4. Data from current study superimposed on physics data reported by Hake (2002) demonstrating efficacy of "interactive engagement" over traditional lecture/laboratory. Three large "stars" represent experimental course from present study. Two large solid circles represent the TWO BEST sections of traditional control courses.

The results of this study are comparable to similar results in physics, which demonstrate that students taught by interactive engagement consistently outperform students taught by traditional lecture and laboratory (Hake 2002). Hake’s report summarized results from 62 physics courses enrolling more than 6500 students and different grade levels and from around the country. I have plotted data from the present study on top of Hake’s physics data (Figure 4). The three large stars represent the interactive/investigative sections from the present study and the two large circles represent the two highest performing sections of traditional lecture/investigative laboratory from this study.

Conclusion

It is well recognized that students bring to class many misconceptions concerning the nature of science and the nature of evolution. These beliefs, which often seem common sense and are reinforced by the media, are particularly resistant to modification — regardless of the pedagogy employed. This study provides some evidence to support the claim that student-active learning, where students are actively engaged in problem-solving, is more effective than traditional instruction in overcoming this barrier. Although with only one exception the data reported are not statistically significant, the consistency of the trends suggest that the observed differences are due to more than sampling error or chance.

References

Gonick L, Wheelis M. The Cartoon Guide to Genetics. New York: HarperCollins, 1991.
Gould SJ. Ever Since Darwin: Reflections in Natural History. New York: WW Norton, 1977.
Hake R. Lessons from the physics education reform effort. Conservation Ecology 2000; 52 (2). Available on-line at , last accessed May 28, 2003.
Halloun I, Hestenes D. Interpreting VASS dimensions and profiles. Science & Education 1998; 6: 553–7.
Lamarck JB de. 1809. Philosophie Zoologique. In: Ames R, Siegelman P, editors. The Idea of Evolution. Minneapolis: Dillon Press, 1966. p 28–9.
Miller J, van Loon B. Darwin for Beginners. New York: Pantheon Books,1982.
Mintzes JJ, Wandersee JH, Novak JD. Teaching Science for Understanding: A Human Constructivist View. New York: Academic Press, 1998.
Novak JD, Gowin DB. Learning How to Learn. New York: Cambridge University Press, 1984.
Odom E. Ecological Vignettes: Ecological Approaches to Dealing with Human Predicaments. Amsterdam: Haywood Academic Publishers, 1998.
Sundberg MD. Assessing the effectiveness of an investigative laboratory to confront common misconceptions in life sciences. In: McNeal A, D’Avanzo C, editors, Student-active Science: Models of Innovation in College Science Teaching. Saunders College Publishing, Philadelphia, 1997. p 141–61.
Sundberg MD, Dini ML. Science majors vs nonmajors: Is there a difference? Journal of College Science Teaching 1993 Mar/Apr; 299–304.
Sundberg MD, Dini ML, Lee E. Decreasing course content improves student comprehension of science and attitudes towards science in freshman biology. Journal of Research in Science Teaching 1994; 31 (6): 679–93.
Sundberg MD, Moncada G. Creating effective investigative laboratories for undergraduates. BioScience 1994; 44 (10): 698–704.
Thomas L. Lives of a Cell: Notes of a Biology Watcher. New York, The Viking Press, 1974.
Udovic D, Morris D, Dickman A, Postlethwait P, Wetherwax P. Workshop biology: Demonstrating the effectiveness of active learning in an introductory biology course. BioScience 2002; 52 (3): 272–81.

About the Author(s): 
Marshall D Sundberg
Department of Biological Sciences
Emporia State University
Emporia KS 66801
sundberm@esumail.emporia.edu

RNCSE 23 (3-4)

Reports of the National Center for Science Education
Volume: 
23
Issue: 
3–4
Year: 
2003
Date: 
May–August
Articles available online are listed below.

Astrobiology and the Search for Alien Life

Reports of the National Center for Science Education
Title: 
Astrobiology and the Search for Alien Life
Author(s): 
David Morrison
Senior Scientist, NASA Astrobiology Institute
Volume: 
23
Issue: 
3–4
Year: 
2003
Date: 
May–August
This version might differ slightly from the print publication.
In another paper in this issue (p 15), I described astrobiology and discussed the ways this field relates to the study of the origin of life on earth. In this paper, I touch on other aspects of astrobiology: studying life in extreme conditions on earth and the initial efforts to search for evidence of life beyond our planet.

In the previous paper, I noted the difficulty of understanding the origin of life, since there is almost no direct evidence from either geological or genetic studies on the first half-billion years of terrestrial history. Here we pick up the story after the emergence of simple cells that already have DNA and RNA and thus are subject to selection as they reproduce and evolve.

Evolution on earth: The highlights

Astrobiology brings a multidisciplinary perspective to biology, as well as to comparing our planet with other potential abodes of life. Someone looking at the history of life from this perspective quickly focuses on microbes. Most of life’s history took place before the first multicellular organisms appeared. Most life today (whether measured by biomass or diversity or chemical interaction with the atmosphere) is still microbial. It is probably microbes, not “little green men”, that we will find when we encounter life on other planets.

Remarkably, the vast majority of microbial life on earth is unknown — recent experiments in molecular taxonomy suggest that fewer than 1% of the microbes in any random sample belong to previously identified or cultured species.

Many popular texts still refer to the microbes as “primitive” and comment on the sluggish pace of evolution prior to the Cambrian explosion. Evolution is sometimes treated as if it did not really begin until the most recent billion years of earth history, and there is an understandable emphasis in museums and popular-level books on evolution of the larger creatures, such as the dinosaurs, or the “smarter” ones, such as dolphins and apes.

When we look at the molecular phylogenetic tree, however, we see hints of a rich evolutionary history spanning the 3 billion years between the emergence of earliest living things and the Cambrian explosion. On the modern tree of life, the metazoans — from mollusks to mammoths — are banished to just a few twigs. From a functional point of view, also, it can be argued that the development of metazoans was just the most recent of several critical milestones in evolutionary history.

The earliest major innovation was the invention of photosynthesis. This may have happened as long as 3.5 billion years before the present (BP). Before that time, living cells had to extract energy (as many still do today) from chemical disequilibria in their surroundings, such as those produced when superheated water dissolved chemicals from the crust in regions of hydrothermal activity. Such strategies are much less efficient than photosynthesis. Once living things developed the complex sequence of chemical reactions that allowed chemical energy to be extracted directly from sunlight, a grand new world of possibilities opened. One of the most important questions in the search for life elsewhere involves our expectations concerning the emergence of photosynthesis on other worlds.

The second great leap, which may have happened at about the same time as photosynthesis, was the emergence of the Eukarya — cells larger and more complex than the prokaryotes (Bacteria and Archaea). Eukaryotic cells contain functionally distinct subunits: a nucleus enclosing genetic information, plus various mitochondria and (for plants) chloroplasts. These microbes are among life’s most successful groups, especially the ubiquitous protists (including amoebae, diatoms, paramecia, and foraminifera). Almost certainly the Eukarya originated in the merging or envelopment of various bacteria; for example, the chloroplasts in many ways resemble cyanobacteria. There is a crucial difference, however, because in the Eukarya the genetic information for each of the subunits as well as for the cell as a whole is combined in the nucleus. Their origin marks a fundamental change in the functionality of the genome.

The third milestone was the invention of sexual reproduction, which happened roughly 2 billion years BP. Certain eukaryotes developed double strands of genes (providing redundant information storage). The next step was to find a way of combining genes from two parents, rather than simply cloning the cell. Sexual reproduction allowed greater genomic diversity, since offspring are not genetically identical. This diversity of populations enhanced the opportunities for selection to favor some genetic combinations over others and accelerate the pace of evolution.

The fourth and final great innovation was multicellular or pluricellular organisms. Sometime before 0.7 billion years BP, life evolved the capability to store and use the genetic information for multiple types of cells within its germ cell. Now a variety of cells types could be manufactured from a single source of genetic information through sophisticated control of gene expression. Once this capability existed, it was relatively simple for these different cell types to form tissues and to link up within a single organism. Thus metazoans — multicellular organisms with cells organized into tissues — became possible.

The preceding is a crude, macroscopic perspective on evolution. When we consider the possibility of life on other worlds, even life that is chemically similar to our own, we must ask ourselves which of these key steps — photosynthesis, multicomponent cells, sexual reproduction, and multicellular organisms — might have taken place there. Our ability to detect and recognize alien life depends on these or similar evolutionary events.

Habitable environments on earth and beyond

To understand the role of life in the universe, we must explore the range of environments that might support living things. Astrobiologists approach this problem in two ways. In this section, I discuss habitability from the perspective of the basic properties of carbon-based life. In the next section, I look at the diversity of environmental conditions on earth where life is found.

Most astrobiologists limit their consideration to carbon chemistry because carbon is abundant and more capable than any other element of forming a wide variety of complex chemical bonds. Besides, carbon-based life is the only sort we could confidently recognize.

Much of organic chemistry is enabled by the presence of liquid water. Water is the best solvent, which is why we use it for washing. The range of temperatures in which water is a liquid (from 0° to 100°C) is precisely the range in which much of carbon-based chemistry is active. At temperatures above 100°C the larger carbon molecules start to come apart, which is why boiling water kills most microbes.

While water molecules are abundant in the universe, liquid water is much less so. Most places are either too hot or too cold. In addition, liquid water requires an ambient pressure greater than 0.006 bars (4.5 mm of mercury); at lower pressures, water can have only two states: solid and gas. The requirement for liquid water directs our attention toward planetary surfaces with temperatures between 0° and 100°C.

In addition to liquid water and organic chemicals, life requires an energy source. Early life on earth extracted energy from dissolved chemicals through fermentation and other reactions. Photosynthesis, however, enables life to tap the much greater energy of sunlight itself. Photosynthesis yields carbohydrates and oxygen gas as byproducts, and these can be used as an energy source by other organisms, such as animals.

A habitable environment, then, seems to require the presence of 3 things: abundant raw material in the form of carbon compounds, liquid water (which points us toward planets), and an exploitable energy source.

Life in extreme conditions

On earth, life has evolved to fill many ecological niches, some of them quite different from our everyday experience. Organisms that live and flourish in such environments are called extremophiles — meaning that their environments seem extreme to us. Most extremophiles are microbes, but these are not necessarily simple or primitive — in fact, a great deal of evolutionary adaptation was required for them to function in these environments.

Most life works best at temperatures between about 15°C and 60°C. Microbes that prefer lower temperature are called psychrophiles, and those that prefer heat are called thermophiles. At the low end, life can often survive at temperatures even below 0°C, although metabolism slows down or stops. Microbes that were frozen and dormant for tens of thousands of years in the Antarctic ice have been revived in our laboratories.

At high temperatures, thermophiles have developed mechanisms to make the chemical repairs that are needed as carbon-based compounds begin to come apart. Unlike the dormant state at low temperatures, adaptation to high temperatures requires active chemical intervention. For example, many microbes flourish in the Yellowstone hot springs at temperatures up to 100°C. The record for a thermophile is 113°C at deep-sea vents. (Note that the pressure of the water above the vent is so great that 113°C is still below the boiling point of water there.)

Other environmental extremes involve moisture, salt, and acid. Many microbes tolerate desiccation in much the way they survive low temperatures, by going into a dormant state and waiting for better conditions to return. Some microbes are so tolerant of high salinity that they can live even in the waters of the Dead Sea. The range of acidity in which life has been found goes from pH less than 0 to greater than 9. One example of an acid environment is the Rio Tinto of southern Spain, which originates in a region of extensive mineral deposits and maintains a steady pH of 2.5 all the way to its mouth (by comparison, lemon juice has a pH of 2). A rich microbial community inhabits this river, with some of the microbes helping to maintain the acidity, because that is the environment they like.

One of the most surprising cases of tolerance to extremes is exhibited by an “atomophile”: the bacterium Deinococcus radiodurans, which is found (among other places) in the cooling water of nuclear reactors. With its highly developed chemical repair mechanisms, D radiodurans can survive ultraviolet or particle radiation up to 6000 rads per hour, a thousand times more than a human can tolerate. It is also resistant to many unpleasant industrial chemicals and is commonly found in toxic waste dumps.

Life has evolved to survive on earth in a remarkable range of environments. Nearly every ecological niche seems to be filled, although in many cases the rate of metabolism is very low. But there are some exceptions. No organism has learned to extract the water it needs directly from ice: the ice sheets of Greenland are not green, in spite of ample sunlight. There are also no organisms that carry out their life cycles entirely in the air. Life (as we know it) requires liquid water and something substantial such as land or an ocean to make a home.

Life on Mars

Within our solar system, Mars is probably the other planet most likely to harbor life. This conclusion has nothing to do with the “canals” of Percival Lowell; the life we are discussing is microbial, not metazoan. Nor today do most scientists support the initial hypothesis put forward in 1996 that the Martian meteorite ALH 84001 contains fossil microbes (although the point is still debated). Rather, optimism about Mars derives from the fact that several billion years BP its climate was different. There is abundant geological evidence from spacecraft exploration that Mars once had a thicker atmosphere and liquid water on its surface.

The 1976 Viking landers carried instruments designed specifically to detect microbial life in the soil, but the results were negative. Although Mars has the most earthlike environment of any other planet in the solar system, the surface is too dry and too cold and too affected by solar ultraviolet radiation to meet the requirements for habitability. However, there is no reason to think that life could not have begun on Mars about 4 billion years BP, since earth and Mars apparently had similar surface conditions then. Future missions will include the return of samples, selected from sedimentary rocks at sites (such as ancient lake beds or hot springs) that once held water. The most powerful searches for Martian life (past or present) will thus be carried out in our laboratories here on earth.

Finding fossil life in ancient rocks would motivate an accelerated search for survivors. We will look for life that evolved to deal with the deteriorating climate of Mars, perhaps by finding some refuge that is warmer and wetter than most of the Martian surface. NASA’s theme in searching for life is “follow the water”. The most likely source of liquid water on Mars today is deep below the surface, where extensive aquifers may exist. Perhaps someday astronauts on Mars will drill deep wells down to this layer of liquid water and finally encounter living alien life.

One interesting twist on the search for life is derived from the presence of ALH 84001 and nearly 30 other Mars rocks that have been identified on earth. These are rocks blasted off the surface by meteorite impacts. Mars and earth are close enough together that they have exchanged material in this way throughout their history (although most of the traffic has been from Mars to earth, as a consequence of the lower surface gravity on Mars). It is possible that some of these rocks may have contained viable microorganisms. Mars might have seeded earth, or the two planets could have exchanged biological material. It is therefore conceivable that if we eventually find living things on Mars, they will be genetically similar to terrestrial life, for the good reason that they are our distant cousins. If so, it will be fascinating to study life that has evolved independently for close to 4 billion years, but we will be no closer to answering the fundamental question of how life began. The “holy grail” of astrobiology is not just to find life elsewhere, but to find and study life that had an independent origin from that on earth.

Life elsewhere in the solar system

Are there other locations in the solar system where there is liquid water? Recent studies of the satellites of the outer planets suggest positive answers, in spite of the cold surfaces of these worlds. In most cases, the putative liquid water is deep beneath the crust. The most tantalizing site, however, is Jupiter’s satellite Europa. Data from the Galileo spacecraft (in orbit about Jupiter 1995–2003) on this Moon-sized world indicate the presence of a global ocean of liquid water beneath an ice crust only a few kilometers thick.

Life requires an energy source, and sunlight does not penetrate below the frozen crust of Europa. Life is therefore unlikely to have evolved photosynthesis there. But internal energy sources may be present in the Europan seas. To remain liquid, Europa’s global ocean must be warmed by heat generated by tides and now escaping from the interior of Europa. Hot (or at least warm) springs might be active, analogous to those we have discovered in the deep oceans of the earth. Europa might therefore support life that derives its energy from the mineral-laden water in such springs.

Although some scientists think that Europa is the most likely place beyond the earth to find life in the solar system, others question whether life could originate in a dark ocean heated only by hot springs. Since we do not know exactly how life formed on earth, it is impossible to evaluate this possibility for Europa. One thing is clear, however: if there is life in the Europan oceans, it is likely to be unrelated to terrestrial life. There is no exchange of rocks between earth and Europa to provide the possibility of cross-contamination, as is the case for Mars. Thus Europa holds out the tantalizing prospect of a second genesis — an independent origin of life. If so, we can hardly guess what that life might be like. Will it be carbon-based? Will it utilize protein chemistry? Will it possesses a genetic material something like DNA or RNA? Or will it be more exotic than we can now imagine?

Habitable planets orbiting other stars

One of the most important recent developments in astronomy has been the detection of planets circling distant solar-type stars — with more than 100 such planets discovered by the end of 2002. These planets cannot be seen directly; they are detected by the “wobble” of their parent stars in response to the gravitational tug of the planets. So far, we can detect only giant planets (like Jupiter and Saturn), and such large planets (without solid surfaces) seem unlikely as the home of life. Further, many of the newly discovered giant planets are on eccentric orbits or cluster close to their parent stars, where temperatures are far too high for liquid water. Still, their existence holds out the prospect of smaller worlds (either earth-like planets or satellites orbiting the giants) that might support liquid water and the other conditions necessary for biology.

In evaluating the prospect for life in distant planetary systems, astrobiologists have developed the idea of a habitable zone — a region around a star where suitable conditions might exist for life. Since the focus is on the presence of liquid water, the usual definition of a habitable zone is the range of distance from the star where water will be liquid on the surface of a terrestrial-type planet (that is, a planet with roughly the mass of the earth).

Obviously the earth is in the habitable zone for the solar system. Note, however, that earth’s surface is above the freezing temperature of water only because the greenhouse effect in our atmosphere raises the average temperature by about 25°C. In the past, when the Sun was fainter, we were even more dependent on a greenhouse effect to maintain clement conditions. Thus, we must consider the nature of any atmosphere as well as the distance from the star in evaluating the range of habitability.

Our neighbor worlds provide some insight into the habitable zone within the solar system. Venus, the next planet closer to the Sun, has evolved through a runaway greenhouse effect into an oven where life is impossible, but it was once probably inside the habitable zone. Mars today is too cold and dry for surface life, but in the past it had a thicker atmosphere and apparently supported surface water (although perhaps its lakes and seas were ice-covered). Today Mars seems to be outside the habitable zone, but if the earth (with its greater ability to retain an atmosphere) were in the orbit of Mars, it might still be relatively warm. The current inhospitable nature of Mars is as much a consequence of its small mass as its distance from the Sun.

This is all very complicated, and scientists still differ in what they consider to be a habitable zone. Roughly speaking, however, the habitable zone in our solar system is limited to the terrestrial planets earth and Mars, and (perhaps early on) Venus.

Biomarkers

From the discussion above, our prime candidate worlds in the search for life beyond the solar system are terrestrial-type planets within the habitable zones of their stars. Astronomers are unable to detect such planets with current technology, but within a decade or so, space missions should allow us to determine how common such habitable planets are and to identify nearby candidate systems for further study. The NASA mission called Kepler, which is to be launched in 2007, is designed to determine the frequency of occurrence of terrestrial planets within the habitable zone of solar-type stars.

The fact that a planet is within the habitable zone does not ensure, of course, that it is actually inhabited. Indeed, one of the most important questions in astrobiology is just that: will life arise naturally when the environmental conditions are correct? It is thus important to consider how we might recognize the signature of life on a distant planet.

Even with the largest space-based telescope we can contemplate, we will never be able to obtain images of distant planets, as we do the worlds in our own solar system, let alone visit them with robot spacecraft. Astrobiologists therefore need a global biomarker — something distinctive to separate a live world from a dead one. To be detectable, these biomarkers should involve changes in atmospheric or surface chemistry that can only be the result of life.

If we observed earth from a great distance, and took sensitive visible-light and infrared spectra, we might just see such biomarkers. The most easily detectable evidence is the presence of abundant free oxygen in the atmosphere, which produces distinctive features in near-infrared spectra. On earth, oxygen is the byproduct of photosynthesis; if life on earth should cease, the oxygen in the atmosphere would disappear within a few thousand years. The oxygen, therefore, is a biomarker. A similar atmospheric gas is methane, produced by microbes. Without the presence of life, methane would be quickly oxidized and disappear from the atmosphere. Probably the most distinctive biomarker for earth is the simultaneous presence of these two gases: oxygen and methane.

Unfortunately, for two billion years the earth was a living planet without the oxygen/methane biomarker in its atmosphere. Astrobiologists are therefore looking in more detail at the possible interactions between ancient microbial life and the atmosphere. One of the themes of astrobiology is to study the co-evolution of life and the planet. Our ability to detect the presence of life someday on an extrasolar planet depends on a better understanding of the complex interactions that could reveal the presence of a biosphere to our spectrometers.

Conclusions

The search for life is just beginning. It may require decades for a thorough exploration of Mars, and Europa is even less accessible. To search for biomarkers on distant earthlike planets requires not only that we discover such planets, but also that we construct enormous telescopes in orbit to measure the composition of their atmospheres in the search for biomarkers. A third possibility, of course, is that a successful SETI program will detect signals broadcast by a technical civilization somewhere in the galaxy. While this seems like a long shot, the rewards of success are certainly sufficient to motivate the search for such signals.

Astrobiology is a science that broadens our perspective on biology to include other worlds. It includes the study of evolutionary adaptations to extreme environments on earth, as well as the potential for life to develop on other planets. Because of its fusion of astronomy and biology (plus generous contributions from geology and chemistry), astrobiology has great public appeal. Dozens of books have been published in the past few years, and more recently astrobiology has found its way into college curricula, especially as a general education introduction to science. Two new textbooks have been published for such “Astrobiology 101” courses (Life in the Universe by Jeffrey Bennett, Seth Shostak, and Bruce Jakosky [San Francisco: Addison Wesley, 2003], and The Search for Life in the Universe, 3rd edition, by Donald Goldsmith and Tobias C Owen [Sausalito (CA): University Science Books, 2001]), and more than 100 college courses are currently offered (see http://nai.arc.nasa.gov/institute/college_courses/). Evolution, of course, lies at the heart of these studies — taken in the wide context of an evolving universe and of the coupled co-evolution of life with its host planet.

Astrobiologists are asking the big questions about the origin, evolution, and distribution of life in the universe. While it may be a long time before we get definitive answers to such questions, the quest for this knowledge is fascinating to educators and the public as well as the research community.

About the Author(s): 
David Morrison
NASA Ames MS 240-1
Mountain View CA 94035-1000
dmorrison@arc.nasa.gov

Faith, the Environment, and Evolution

Reports of the National Center for Science Education
Title: 
Faith, the Environment, and Evolution: An Interview with John F Haught
Author(s): 
Phina Borgeson
Volume: 
23
Issue: 
3–4
Year: 
2003
Date: 
May-August
This version might differ slightly from the print publication.
John F "Jack" Haught is Landegger Distinguished Professor of Theology at Georgetown University in Washington DC and director of the Georgetown Center for the Study of Science and Religion. His area of specialization is systematic theology, with a particular interest in issues pertaining to science, cosmology, ecology, and religion. He is the author of several books, including Science and Religion: From Conflict to Conversation, God After Darwin: A Theology of Evolution, and Responses to 101 Questions on God and Evolution (reviewed by Phina Borgeson on p 52); his newest book, Deeper Than Darwin: Evolution and the Question of God, was published in 2003 by Westview Press.

Haught visited the University of California, Davis, on March 18 and 19, 2002, to deliver the annual St Augustine Chair Lecture of The Belfry campus ministry, which was concomitantly was the keynote address of a conference on Care for God’s Creation: Spirituality and Environmental Stewardship. NCSE Faith Network Project Director Phina Borgeson attended and interviewed Haught afterward.


RNCSE: The organizers of the Care for God’s Creation event wisely, in my opinion, asked you to speak on evolution as an important foundation for any faith-based environmental activism. It has seemed to me that there are similarities between people who deny evolution because of their beliefs and those who disparage environmentalism out of faith. What would you say is the theological common ground between those two groups?

Haught: Well, first, they are both dualistic in their thinking; it is their view of reality that we humans are essentially spiritual beings only accidentally imprisoned in a material universe. Second, and perhaps most important, it is their view of ultimate destiny that militates against their taking the environment seriously. I grew up in the country, on a family farm in rural Virginia. There is a radio program I listen to on Sunday afternoons that plays the kind of music common in that area, "Stained Glass Bluegrass". I still have an affection for the music, but not for the theology, which says that our ultimate home is elsewhere: earth is like a school for souls, and when it is all over, we will be harvested away from earth to heaven. To such a mindset, taking care of this planet seems pointless. And even if those who espouse these beliefs accept evolution, they are not interested in doing anything with it theologically. The environment is not important when the destiny of the individual is deemed significant and the destiny of all of creation is not. Those of us doing theology after Darwin, though, can speak with even more certainty about the inseparability of cosmic and human destiny.

RNCSE: What about parallels between the two in activism and methods?

Haught: The detractors project onto both evolution and environmentalism their own sense of what they have been taught is evil. Basically, evolution is seen as evil and the avenue by which modernity has allowed in all kinds of ills. For many who would deny it, the word "evolution" is so symbolically charged that of itself, it arouses a moral impulse toward activism.

Evolution, of course, is change over time. Evolution’s detractors have a concept of God and a concept of order according to which change is considered demonic or even satanic. And they have a lot of conservative money to fight change.

They do not want perfection in Whitehead’s sense, which includes both novelty and order. they want it in a trivial form devoid of novelty. For Whitehead, perfection is not attainable, but a goal, the highest possible integration of novelty and order (which he also called beauty). Too much novelty is chaos; too much order is banality.

Creationists and those who reject environmentalism also cannot distinguish between a sacramental outlook, in which nature is symbolic or revelatory of God, and pantheism, in which nature is equated with God. There does seem to be less creationism in sacramental churches, but there is a growing "intelligent design" movement in Catholicism.

RNCSE: Of course — Michael Behe is a Roman Catholic, and the University of San Francisco, a Jesuit institution, hosted the 2002 IDEA conference.

In your lecture, you talked about how any Christian theology must be related to the revelation of God in the person of Jesus. You identified three key attributes of Jesus: humility, self-gift, and opening up of the future, or promise. It seemed to me that each of these runs counter to the theology implicit in "intelligent design".

For example, when talking about God’s self-gift, you said, "Revelation is not the passing of information from heaven to earth, but the infinite entering the finite world." This seemed to allude to the theological uses, or misuses, of information in the work of Phillip Johnson and William A Dembski. Would you care to comment?

Haught: Well, that view is based on Karl Rahner’s theology, especially his thinking that revelation is at root the mystery of God pouring itself without reservation into the creation. I have an intuition that if you look upon nature simply as design, it tends to freeze out the novelty that brings life. Dawkins said that design is "brittle". But there are always new forms of order pouring in from the infinite. Because the fullness of divine infinity cannot be received all at once by the finite cosmos, something new is always coming into the universe. The rigidity of design is a barrier to the self-gift of the divine. Good evidence for this is that we see no perfect adaptations.

RNCSE: Of opening up the future, you said, "The universe is seeded with promise rather than design." Your comments?

Haught: Theologically, promise is a field of endless possibilities. Jürgen Moltmann (a contemporary German theologian, influential, among other things, in the renewal of interest in eschatology among liberal Protestants and in propounding a theology of hope) has developed some interesting ideas here. He reminded us that in the biblical view of things, the word "God" means "Future". Possibilities are more powerful than actualities. Possibilities can become actual, but the actual can no longer become possible. The conception of God as the Designer is just too hard and dead to capture the rich way God relates to nature, drawing us into the future in a Teilhardian way.

RNCSE: What about humility? Is there a way you would contrast your understanding of that with the theology of the "intelligent design" crowd?

Haught: It seems to me that fear drives people toward design: fear of change, of novelty, of the infinite. "Intelligent design" puts a sacred canopy over their lives. But design does not truly conquer fear. Design is about a God of power and might rather than a God who shares in our sufferings. Like most natural theology, "intelligent design" fails to make room for the cross. Yet it is a trust in the self-emptying Jesus in passion and crucifixion that drives out fear.

RNCSE: I know that you are aware of the efforts to insert "intelligent design" into the science education standards in Ohio. What would you say to clergy and other religious leaders there who want to oppose "intelligent design" from a theological perspective?

Haught: Well, before I say anything about theology, let me say that from the point of view of science, it is just plain inappropriate. Appeals to "intelligent design", for example Michael Behe’s "irreducible complexity", are theological diversions, not scientifically fruitful suppositions.

Theologically, "intelligent design" trivializes both science and the scriptures by bringing in God at the level of science. It has religion moonlit in an explanatory slot that belongs to science.

Proponents of "intelligent design" and of evolutionary materialism agree that there is one explanatory slot — so we need to fit God into the slot or he will not be present at all. If there is only one slot, there is going to be conflict. In contrast, in my new book Deeper than Darwin, I argue for explanatory pluralism, on which such a conflict need not arise.

The proponents of "intelligent design" seem unable to separate evolution from evolutionary materialism. They throw the baby out with bath water, discarding good science, and at the same time turning God into a tinkerer rather than a creator.

RNCSE: How did you get into this anyway?

Haught: Well, when I was in Catholic seminary, I got into reading Teilhard de Chardin, whose work struck a chord with my cosmic romantic sense. I have also delighted in Whitehead and his romantic reaction to the dominant philosophy of his place and time. I find that Science and the Modern World is still the most influential book I have read, and the best critique of scientism. I think Whitehead was the first postmodernist.

When I left the seminary, I worked in systematic theology, with no idea of going into science and religion as a field. But when I arrived at Georgetown more than thirty years ago, I realized that there was no course to help students to integrate what they were learning in science with what they were learning in the humanities. I like to think that my present work on evolution and theology is helping people — not just my students — undertake a religious voyage of discovery that respects both classical spirituality and the evolutionary discoveries of modern science.

The Astrobiological Perspective on Life's Origin

Reports of the National Center for Science Education
Author(s): 
David Morrison
Senior Scientist, NASA Astrobiology Institute
Volume: 
23
Issue: 
3–4
Year: 
2008
Date: 
May-August
This version might differ slightly from the print publication.
Astrobiology is a new term for the study of the origin, evolution, distribution, and destiny of life in the universe. It uses multiple scientific disciplines and space technologies to address some of the most profound questions of humankind: How did life begin? Are there other planets like earth? What is our future as terrestrial life expands beyond the home planet? For the first time in human history, advances in the biological sciences, informatics, and space technology make it possible for us to provide some answers.

In this paper, I discuss contributions that the new field of astrobiology can make to questions of life’s origins. I am an astronomer and space scientist, not a biologist or biochemist. My perspective is therefore that of an interested outsider. But as an astrobiologist, I look at the state of knowledge in the field and try to make some judgment about directions in which current research seems to be taking us.

The paper has 3 parts. First is a discussion of the nature of astrobiology, using the NASA Astrobiology Roadmap as a way of organizing the subject. Second is a review of the conditions on earth when life began. Third is a perspective on current origins research.

The nature of astrobiology

The United States National Aeronautics and Space Administration (NASA) has encouraged the new discipline of astrobiology by organizing workshops and technical meetings, establishing a NASA Astrobiology Institute, providing research funds to individual investigators, ensuring that astrobiology goals are incorporated in NASA flight missions, and initiating a program of public outreach and education. NASA’s role comes from its history of studying the origin of life and searching for evidence of life on Mars and elsewhere in our solar system. These studies have traditionally been called “exobiology”. Under the broader umbrella of astrobiology, however, research has expanded to include the search for life within other planetary systems, as well as investigation of the response of terrestrial life to global changes on the earth and to exposure to conditions in space and on other worlds. Astrobiology addresses not only our origins, but also our aspirations to become a space-faring civilization.

One description of astrobiology is provided by the NASA Astrobiology Roadmap (available at http://astrobiology.arc.nasa.gov/roadmap/). This Roadmap, completed in 1999, defines the content of astrobiology as perceived by scientists at its birth. It is a starting point only, and astrobiology is maturing as new information is obtained and diverse scientists bring their own perspectives to this discipline.

Astrobiology addresses 3 basic questions, which have been asked in some form for generations.

  • How does life begin and evolve? (Where did we come from?)
  • Does life exists elsewhere in the universe? (Are we alone?)
  • What is life’s future on earth and beyond? (Where are we going in space?)
These very general questions are then explored by means of 10 scientific goals:

1. Understand how life arose on the earth.

Terrestrial life is the only form of life that we know, and it appears to have arisen from a common ancestor. How and where did this remarkable event occur? We can now perform historical, observational, and experimental investigations to understand the origin of life on our planet. We should determine the source of the raw materials of life, either produced on this planet or arriving from space. We should seek to understand in what environments the components may have assembled and what forces led to the development of systems capable of deriving energy from their surroundings and manufacturing copies of themselves.

2. Determine the general principles governing the organization of matter into living systems.

To understand the full potential of life in the universe, we must establish the general physical and chemical principles that lead to the emergence of systems capable of energy extraction and growth (catalysis and metabolism), generating offspring (reproduction), and changing as conditions warrant (evolution). Must all life be based on something similar to terrestrial biochemistry and molecular biology? How can laboratory experiments and computational simulations help us to understand life as a more general phenomenon?

3. Explore how life evolves on the molecular, organism, and ecosystem levels.

Life is a dynamic process of changes in energy and composition that occurs at all levels of assemblage, from the molecular level to ecosystem interactions. Much of traditional research on evolution has focused on organisms and their lineages as preserved in the fossil record. However, processes such as the exchange of genetic information between organisms and changes within DNA and RNA are key drivers of evolutionary innovation. Modern genetic analysis, using novel laboratory and computational methods, allows new insights into the diversity of life and evolution at all levels.

4. Determine how the terrestrial biosphere has co-evolved with the earth.

Just as life evolves in response to changing environments, changing ecosystems alter the environment of earth. Scientists can trace the co-evolution of life and the planet by integrating evidence acquired from studies of current and historical molecular biology (genomics) with studies of present and historical environments and organismal biology. We seek to understand the diversity and distribution of our ancient ancestors, to identify specific chemical interactions between the living components of the earth (its biosphere) and other planetary subsystems, and to trace the history of earth’s changing environment in response to external driving forces.

5. Establish limits for life in environments that provide analogs for conditions on other worlds.

Life is found on the earth anywhere liquid water is present, including such extreme environments as the interior of nuclear reactors, ice-covered Antarctic lakes, suboceanic hydrothermal vents, and deep subsurface rocks. To understand the possible environments for life on other worlds, we must investigate the full range of habitable environments on our own planet, both today and in the past.

6. Determine what makes a planet habitable and how common such worlds are in the universe.

Where should we look for extraterrestrial life? Based on our only example (life on earth), liquid water is a requirement. We must therefore determine what sort of planets are likely to have liquid water and how common they might be. Studying the processes of planet formation and surveying a representative sample of planetary systems will determine what planets are present and how they are distributed, essential knowledge for judging the frequency of habitable planets.

7. Determine how to recognize the signature of life on other worlds.

We are poised on the brink of searching for life, past or present, on a variety of worlds. This search requires that we be able to recognize extraterrestrial biospheres and to detect the signatures of extraterrestrial life. We must learn to recognize structural fossils or chemical traces of extinct life that may be found in extraterrestrial rocks or other samples. And we must develop a catalog of possible signatures of life that can be identified astronomically in planets circling other stars.

8. Determine whether there is (or once was) life elsewhere in our solar system, particularly on Mars and Europa.

Exciting data have presented us with the possibility that at least two other worlds in our solar system have (or have had) liquid water present: Mars and Europa. Extensive exploration of the Martian surface will be required to evaluate the total potential for life on that planet, both past and present. Furthermore, exploration of the subsurface probably offers the only credible opportunity to find extant life on either Mars or Europa.

9. Determine how ecosystems respond to environmental change on time scales relevant to human life on earth.

Research at the level of the whole biosphere is needed to examine the habitability of our planet over time in the face of both natural and human-induced environmental changes. To help to ensure the continuing health of this planet and to understand the potential long-term habitability of other planets, we need predictive models of environment–ecosystem interaction.

10. Understand the response of terrestrial life to conditions in space or on other planets.

What happens when terrestrial life is moved off its home planet and into space or to the moon or Mars, where the environment is very different from that of earth? Can organisms and ecosystems adapt to a completely novel environment and live successfully over multiple generations? Are alternative strategies practical, such as bioengineering organisms for specific environments? The results from attempting to answer such questions will determine whether earth’s life can expand its evolutionary trajectory beyond its place of origin.

Although it is defined in terms of a research agenda, astrobiology also lends itself to education and outreach. The three theme questions strike a chord of interest among both students and the public. Courses built around these questions offer a powerful platform to discuss issues such as deep time, astronomical and biological evolution, and our place in the universe. On a slightly more sophisticated level, this multidisciplinary field illustrates different styles of approaching science such as contrasting the historical versus experimental research and exploratory versus hypothesis-driven research. A new NSF-supported upper-school curriculum, “Voyages Through Time”, provides a highly appealing introduction to evolution on multiple levels: evolution of the universe, planets, life, and intelligence. At the college level, many astronomers (in particular) have begun to offer general-education courses on “astrobiology” or “life in the universe”. Two new college-level textbooks have been published, and the popularity of such courses is rapidly growing.

The origin of life on earth: Context

The first goal of astrobiology discussed above is to understand the origin of life on earth. Such a study requires that we look at the astronomical and planetary evidence concerning the early environment of earth, as well as the likely chemical pathways that led to life. This study overlaps with the two goals that deal with the general conditions for the origin of life in the universe and with understanding the evolution of life on earth, especially in the microbial world.

Let us be clear at the beginning that we do not understand the origin of life on earth in any detail. Indeed, we are not even sure that life began here. There are some arguments that Mars might have been a more suitable environment for the origin of life 4 billion years ago. Since Mars and Earth have exchanged materials throughout their history, it is possible that life has migrated from one planet to another. This modern form of panspermia has its advocates, but the simplest hypothesis is that life formed on earth. If it began on Mars instead, the processes are probably similar to those that we hypothesize for our own planet.

The solar system formed 4.5 billion years ago from a collapsing cloud of gas and dust that already contained a rich complement of organic material. Astronomical investigations of similar “molecular clouds” that exist today have revealed more than 120 molecules, including such complex substances as ethyl alcohol. The so-called biogenic elements (oxygen, carbon, nitrogen, sulfur, and phosphorus) are among the most common interstellar constituents, once we get beyond hydrogen and helium, which make up 99% of the visible universe. Given the abundance of hydrogen and oxygen, water is one of the main molecules. The simple building blocks for life were thus readily available even before the formation of the planets.

The planets themselves condensed from a disk of gas and dust spinning around the protosun. Some of the pre-existing organic chemicals probably survived this formation process, but most may have been destroyed and then reconstituted within the cooling disk, and perhaps destroyed a second time as the planets coalesced. We know from the study of the oldest meteorites that organics were abundant in the disk; the common carbonaceous meteorites are composed of a few percent carbon by weight, partly elemental and partly in the form of organic compounds. One of these, the Murchison meteorite, yielded 74 separate amino acids. Most of these included equal amounts of right- and left-handed molecules, indicating their non-biological origin. The earth and other rocky planets accreted a veneer of volatiles (including water) and organics from the rain of comets and meteorites that continued for the first half-billion years after the surface cooled. These external sources may have been a more important source of organics than Miller-Urey–type synthesis in the atmosphere and ocean, especially as the initial atmosphere of earth is now thought to have consisted largely of carbon dioxide and been neither strongly reducing nor strongly oxidizing.

What were conditions like on the early earth? Since no rocks have survived from that era, we do not know for sure, but some generalizations seem robust. Although initially hot, the surface layers cooled quickly, and oceans formed. The hot interior undoubtedly contributed to a high rate of volcanism, but surface conditions were then, as now, dominated by solar heating, not volcanism. From their study of stellar evolution, astronomers are confident that the early sun was about 35% less luminous than today (a condition called the “faint young sun paradox” by those who note the contradictory evidence for a relatively constant surface temperature over the history of the earth). Therefore either the earth had a large atmospheric greenhouse effect to maintain surface temperatures above freezing or else the primitive oceans froze. We can imagine an initial carbon dioxide greenhouse effect that partly compensated for the faintness of the sun but left frozen oceans like the Arctic Ocean today. The marine environment thus paradoxically included both a relatively cold surface and an abundance of volcanically-driven hydrothermal systems in the depths. However, there probably were not any of Darwin’s “warm little ponds” on the surface, and the surface might have been bathed in ultraviolet light, depending on the mass and composition of the early atmosphere.

Other external agents in addition to the faint sun influenced the environment of the early earth. The lunar cratering history, among several lines of evidence, shows that the rate of asteroid and comet impacts on the earth was much higher before 3.9 billion years ago. Although it is unclear whether there was a short-lived burst of impacts (a “late heavy bombardment”) or a steadily declining impact rate dating all the way back to the accretionary period, the impacts were sufficient to influence the surface environment. Then as now, the greatest effects are from the rarest, largest impacts, happening at intervals of millions of years. It is likely that the earth was struck several times with sufficient energy to boil away most or all of the oceans. Although the surface would cool and the oceans recondense within a few thousand years of such an impact, the effects on any nascent life would have been catastrophic. This bombardment by a few projectiles hundreds of kilometers in diameter has been termed the “impact frustration” of the formation of life. It suggests that life might have formed several times and then been wiped out in such a sterilizing catastrophe. It also suggests the presence of one or more thermal bottlenecks in the early evolution of life, a topic I will return to below.

The origin of life on earth: Evidence

There is very little surviving geological evidence from the first 500 million years. What we know of impact history, for example, is derived from studies of the moon, not directly of the earth itself. The earliest fossils date from sometime after the end of the heavy bombardment.

Study of the early geological record of life dates back half a century, when Stanley Tyler, Elso Barghoorn, and William Schopf identified fossil microbes in the 2.1 billion–year-old Gunflint chert. By 1993, Schopf had found what appeared to be the oldest fossils in the Apex chert of Western Australia at 3.46 billion years. Schopf also suggested on the basis of morphological evidence that these fossil microbes were probably photosynthetic cyanobacteria. However, this work has recently come under attack, and at this writing the situation remains unresolved. In particular, the crucial conclusion that photosynthesis was operative on earth 3.5 billion years ago is in dispute. In any case, there seems to be no question that microbial fossils can be dated to at least 3.0 billion years. Macroscopic fossils in the form of stromatolites — layered constructs built up by generations of microbial mats — have also been found with similar ages.

A complementary approach is to look for an isotopic signature that indicates the presence of life in sufficient quantities to influence the global chemistry of the planet, even if individual fossils have not survived. Stephen Mojzsis and others argue on this basis for the presence of diverse bacteria on earth before 3.85 billion years. If these interpretations are correct, the interval between the end of the late heavy bombardment and the development of a robust global biota is remarkably short.

The major alternative way to study early life is to examine genomic evidence. Similarities and differences in DNA and RNA sequences illustrate relationships related to their lineage. In the case of the metazoans whose fossil remains dominate natural history collections, genomic analysis is a powerful supplement to more traditional studies of evolution. In the microbial world, such studies provide us with almost our only access to the lineages of life. Given that life on earth was exclusively microbial for the first 85% of its history, and that microbes still dominate in terms of biomass and range of habitats, these tools are invaluable for the astrobiologist. Much of astrobiology research is focused on the smallest but most numerous of life’s creatures.

Carl Woese pioneered the comparison of 16s mitochondrial RNA, a highly conserved sequence that can be found in almost every living thing. By the late 1980s, he had established the division of life into 3 domains, Bacteria, Archaea, and Eukarya. The molecular phylogenetic “tree of life” based on mitochondrial RNA provides us with an entirely new way to look at the diversity of earth’s biota. This diversity, and by implication its evolutionary history, is dominated by microbes within all three domains; the metazoans that have evolved since the Cambrian explosion are banished to a few outlying twigs. Although we do not know the rate of change for mitochondrial RNA in any absolute sense, the conclusion is clear that natural selection has been at work throughout the development and diversification of the microbial world. Today’s microbes should not be called primitive; they are in fact highly versatile creatures that occupy a much greater range of ecological niches than do the more familiar Cambrian metazoans.

Molecular phylogeny is based on the relationships among extant biota. It cannot be used to analyze the mineralized fossils that make up most of the historical record of life on earth — we cannot, for example, use gene mapping to compare an Eohippus with a modern horse, as we can a human and a chimpanzee. Still less are we able to determine the genomic content of ancient microbes, which must have been quite different from anything that survives today. But it is possible to determine which extant microbes are probably similar to the inferred precursors of modern life. This is sometimes ambiguous, especially when we consider that there has been a history of gene transfers among different lineages that can shuffle the deck in ways that make reconstruction nearly impossible. With these caveats, however, a number of suggestions have been made that the most “primitive” organisms today are anaerobic thermophiles — that is, microbes that are happy in oxygen-free environments at high temperatures. Many are also methanogens, microbes that generate methane. These studies suggest, even if they do not prove, that our earliest common ancestors had similar properties.

Even if the common ancestor or ancestors of today’s life were high-temperature, methane-producing microbes, this does not mean that these are representative of the first life. Almost certainly there were many precursors that existed and evolved before the invention of DNA. In addition, however, the last common ancestor is likely to have been the survivor of a “bottleneck” resulting from a catastrophe that wiped out its predecessors. One such possibility is the largest impacts of the heavy bombardment. If the surface and upper layers of ocean were sterilized by an impact, the most likely survivors would be thermophiles from the ocean depths, and it is these survivors who could have repopulated the planet.

The origin of life on earth: Theory

Putting the pieces together to form the first life is a daunting problem. Many scientists who look at the great progress that has been made in understanding the chemical steps along the road toward life are justifiably pleased and optimistic. Others look at the huge gaps that remain and are more cautious. The following is the briefest overview of many complex issues. In preparing this summary, I have been influenced by Belgian Nobel laureate Christian de Duve (Vital Dust: Life as a Cosmic Imperative [New York: Basic Books, 1995]; Life Evolving: Molecules, Mind and Meaning [New York: Oxford University Press, 2002]) and by Australian physicist Paul Davies (The Fifth Miracle: The Search for the Origin and Meaning of Life [New York: Simon & Schuster, 1999]).

The earliest life needed to acquire several basic capabilities. These include assembly of the necessary raw materials within a structure, metabolism (extracting useable chemical energy from the environment), and reproduction, which ultimately involved information-storing molecules such as RNA and DNA that were themselves capable of replication. Each of these is a challenge, and they can hardly have appeared simultaneously.

The first step was surely the chemical factory that extracts energy and uses it to assemble complex molecules. Many such chemical reactions were possible, especially in a rich organic “soup” of amino acids and other organic chemicals. The key was to be able to select and control the rate of these reactions using the biological catalysts called enzymes. The energy sources could have included the conversion of sugars to alcohol or lactic acid by fermentation, or the formation of methane from carbon dioxide and hydrogen by oxidation, depending on available raw materials.

As chemical synthesis became more important, it was necessary to segregate different materials physically. Such segregation can be accomplished by membranes composed in part of lipids, which react with water to form nearly impenetrable barriers. A number of recent experiments and computer simulations have studied simple membranes and the ways they can incorporate proteins to permit partial permeability. A successful cell (or protocell) must eventually develop the ability to admit food and expel waste. Such simple membranes can readily form closed quasi-spherical chambers. In one interesting experiment, organic materials extracted from a meteorite spontaneously formed such closed systems when exposed to water.

Today, DNA is life’s primary information storage and retrieval system, but we also use a simpler system based on RNA, which has the property of participating in protein synthesis as well as storing information. Most workers now think that an RNA world must have preceded the development of DNA. Gerald Joyce of the University of California, San Diego, among others, has carried out extensive experimental studies of the RNA world, demonstrating the ability of RNA to evolve in the test tube. DNA could later have been developed as a more stable information storage system by something akin to the reverse transcription process that can still be observed today.

What processes brought these components together? De Duve makes the case that it cannot have been chance — the probabilities are far too small for self-assemblage of even the simplest such systems in the lifetime of the universe. To paraphrase de Duve, the process must have involved many chemical steps that had a high probability of taking place under prevailing conditions. This progression must have led from prebiotic organic chemistry to biochemistry, and selection effects must have been important in favoring certain chemical pathways. If this is correct, the process could have been rapid, and life should have been able to start in the few million years of stable conditions that separated major impact catastrophes.

The product of this sequence of events — the first protocells — may have been quite different from life that survives on earth today. Even the oldest common ancestor of today’s life probably represents a much more sophisticated system than the first recognizable life. But once natural selection came into play, the means existed for life to evolve. The key challenge, it seems to me, is to understand the selection processes that acted before the formation of the first protocell. It is these processes that must have guided the complex sequence of chemical changes that gave birth to life on the early earth, and, if life exists there, in the rest of the universe, too.

About the Author(s): 
David Morrison
NASA Ames MS 200-7
Mountain View CA 94035-1000
dmorrison@arc.nasa.gov

The Scary Story

Reports of the National Center for Science Education
Title: 
The Scary Story: Cartoon commentary
Author(s): 
Jay Hosler
Volume: 
23
Issue: 
3–4
Year: 
2003
Date: 
May-August
This version might differ slightly from the print publication.

RNCSE 23 (5-6)

Reports of the National Center for Science Education
Volume: 
23
Issue: 
5–6
Year: 
2003
Date: 
September–December
Articles available online are listed below.

The Textbook Choosers' Guide

Reports of the National Center for Science Education
Title: 
The Textbook Choosers' Guide
Author(s): 
James P Barufaldi and William V Mayer
Volume: 
23
Issue: 
5–6
Year: 
2003
Date: 
September–December
Page(s): 
7–8
This version might differ slightly from the print publication.

[Science instruction in K–12 schools frequently depends strongly on textbooks that the school or district has approved for use in its curriculum. In this article we excerpt the main points from one of the brochures on the NCSE web site to help our readers to ask questions and be involved in the process of textbook selection in their own communities.]

Textbooks are frequently chosen or rejected for trivial reasons. Appearance often takes precedence over modernity, accuracy, and explication of the discipline. Textbooks frequently look better than they read. One must be concerned with what a textbook says and how it says it. Illustrations and other materials that accompany the text should be coordinated with the narrative and included to clarify a concept or a process.

Here are 10 points to consider when evaluating a science textbook.

Pedagogical points

  • Beware the encyclopedic text — the one that purports to “cover” every conceivable aspect of the discipline. No textbook can do so, and no student should be asked to memorize such a wealth of detail. Instead, consider whether the text fairly presents the major concepts of the discipline and provides examples to illuminate them. The adequate development of selected major principles is more beneficial to the student than are reams of details.
  • Beware of any text that emphasizes memorization of vocabulary. Students should learn new words as they become involved with a new discipline; selected useful and and meaningful vocabulary can be an inestimable aid in broadening understanding. However, avoid any book that substitutes concentrating on words for their own sake rather than as a support for a narrative of inquiry.
  • Beware of the text that does not read well — one written in short choppy sentences that develop detail but not a cohesive narrative. The text should provide a narrative of inquiry rather than a rhetoric of conclusions. It should build on previous information and serve to develop a basis for intellectual growth as the student proceeds through the book. A text should not be merely a passive reading experience, but should be designed to be interactive — eliciting responses from the student by requiring activity related to the subject under consideration.
  • Beware of the dogmatic textbook. Science is an ever-growing body of data constantly refined on the basis of new evidence. Texts that present the corpus of science as a fixed and unchanging mass of evidence do not prepare students to live in a world where change may be the only constant. However, texts should also present the settled areas of science as just that — they should not give students the impression that science is a body of untested hypotheses, guesses and ever- changing data.
  • Beware of the text as the sole source of scientific information. The textbook must be regarded as an introduction to science that provides a foundation for future learning. Activities should be included that will expand the student’s horizons and send students to other sources of information on the topic. The text should be teaching the student how to learn and should include activities for independent information gathering.

Content points

  • Beware of the text that does not explain the nature of science. One of the major reasons students take science courses is to become acquainted with science as a way of knowing. The processes of science should permeate the textbook and not be confined to an isolated section on what is erroneously referred to as the “scientific method”. Also avoid textbooks that present science as a process of uncertainty or include phrases such as “some scientists believe” or “many scientists agree”. Texts should make it clear that scientists reach their conclusions on the basis of currently available data, not based on personal belief or by vote.
  • Beware the text that does not clearly explain the role of controlled experiment, hypothesis formulation, and theory in science. These are basic research tools of the scientist, and their proper use has led science to its great contributions.
  • Beware of the bland textbook — the one written in such a way as to eliminate controversial or contentious issues and the one that presents the sciences simply as a fixed body of facts unrelated to contemporary issues. The nature of scientific controversy should be presented. Scientific problems currently unresolved should be discussed. Students should be encouraged to analyze, synthesize, and evaluate data collected in support of various hypotheses.
  • Beware the textbook that emphasizes only one aspect of the discipline — for example, a biology text that presents biology only in terms of morphology and systematics — and ignores other aspects of the discipline. No text can present all aspects of the subject, but acceptable texts should present some of the different approaches within the discipline — for example, in biology, topics such as ecology, genetics, growth and development, evolution, and behavior. Further, the interrelationships of science with social and technological issues should permeate the text.
  • Beware the classical textbook — the one that gives the student an impression that science is a historical study, not a vital, ongoing exercise. A textbook must deal in some measure with current areas of research and contemporary problems to prepare students for the issues they will face in the future as individuals or as voting citizens. It should emphasize how scientists are currently approaching and trying to solve contemporary problems in health, the environment, and so on.
About the Author(s): 
James P Barufaldi
The University of Texas at Austin
Center for Science and Mathematics Education
1 University Station D 5500
Austin TX 78712

James P Barufaldi is Ruben E Hinojosa Regents Professor of Education at the University of Texas, Austin. The late William V Mayer was Professor Emeritus in the Department of Biology at the University of Colorado, Boulder.

Darwinism and Intelligent Design: The New Anti-Evolutionism Spreads in Europe

Reports of the National Center for Science Education
Title: 
Darwinism and Intelligent Design: The New Anti-Evolutionism Spreads in Europe
Author(s): 
Ulrich Kutschera
Institut für Biologie, Universität Kassel
Volume: 
23
Issue: 
5–6
Year: 
2003
Date: 
September–December
This version might differ slightly from the print publication.
According to a 2002 poll of adult Europeans conducted by a professional institute (IHA-GfK, Hergiswil, Switzerland), only 40% of the respondents agreed with the statement that the universe, the earth, and all organisms of the biosphere are entirely the product of a natural evolutionary process. Twenty-one percent were adherents of theistic evolution, 20% believed that God created all organisms at one time within the last 10 000 years, and 19% answered “don’t know/ other opinion” (http://www.factum-magazin.ch/whats_new/news.cgi?v=news&c=Schoepfung&id=04073104514.shtml). Among the 20% who believed in a recent creation — mostly fundamentalist Christians who are biblical literalists — the highest percentage was in Switzerland (21.8%), followed by Austria (20.4%) and Germany (18.1%). Compared with the situation in the United States, where almost half of all adults deny evolution as a fact of nature (see for example Futuyma 1995; Gross 2002), the creationists in German-speaking European countries (Kutschera 2003) are still a minority that accounts for just one fifth of the population. Who are the conservative Christian anti-evolutionists in Europe and how are they organized? What role does the “intelligent design” (ID) argument play in the anti-evolution propaganda in European countries?

Creationism and ID in Europe

In March 2002, British newspapers revealed that Emmanuel College in Gateshead, a prestigious Christian-run secondary school that has been praised by Prime Minister Tony Blair, presented the creationist view as a “scientific” alternative to evolution (Gross 2002). After leading scientists, including Richard Dawkins, wrote to the Office for Standards in Education, and the bishop of Oxford intervened (“Evolution is a theory of great explanatory power … and not a faith position as the college in Gateshead alleges”), the teaching of creationism as a scientific alternative was suspended (Gross 2002).

In Switzerland and Germany, two societies, pro Genesis (http://www.progenesis.ch) and the Studiengemeinschaft Wort und Wissen (http://www.wort-und-wissen.de) are the dominant anti-evolutionist associations. They publish newsletters, distribute videotapes, and promote their viewpoint via two professional journals, factum and Studium Integrale Journal (Kutschera 2003). The most important production of the European anti-evolutionists is a book edited by the Wort und Wissen employee Reinhard Junker and the microbiologist Siegfried Scherer (a fellow of the Discovery Institute) entitled Evolution: Ein kritisches Lehrbuch [Evolution: A Critical Textbook] (2001). In the preface, the authors elucidate their aim: to present an alternative to the “concept of macroevolution”, which is, in their view, not supported by convincing data. Interestingly, microevolution (the origin of new species that display the same basic body plan) is accepted, but the occurrence of novel “types” in the fossil record is disputed and described as an unsupported claim of the Darwinists.

Junker and Scherer revitalized the Bible-based pre-Darwinian “theory of creation” as a theistic alternative to evolution. In order to circumvent logical problems concerning the documented continuum between micro- and macroevolution, the authors introduced a new “species concept”, the so-called Basic Types of life. Since, according to chapter 1 of Genesis, God created animals and plants after their own kind (microorganisms, fungi, and protoctista are not mentioned), these kinds must represent higher taxonomic groups. As examples, Junker and Scherer discuss the following Basic Types: Anatidae (ducks, geese, and swans), Canidae (dogs, wolves, and foxes), Triticeae (wheat, barley, and oats) and humans (one species, Homo sapiens). This novel “Bible-based theory” postulates that God created an in-built capacity for variation within a kind, but not between different Basic Types. Hence, what the Darwinists label as macroevolution is replaced by supernatural acts of the Creator, but microevolution (that is, the diversification of the Basic Types, with the exception of humans) is theistic–naturalistic evolution. This concept was introduced by Scherer several years ago at the Third International Conference on Creationism and at the European Creationist Congress (http://www.pages.org/bsc).

In the last chapter of their book, Junker and Scherer discuss the possibility that the Creator may communicate with the biologist via “design-signals”, which are expressed in the beauty of flowers, butterflies, and other creatures. On these pages, the designer is equated with the biblical Creator-God. This European version of modern “theobiology” has been classified as ID-creationism (Kutschera 2003).

The impact of the Junker and Scherer textbook is difficult to assess. Due its low price and its attractive design, many more copies have been sold than of academic textbooks on evolution. It has been translated into several European languages (Russian, Serbian, Finnish, and Portuguese), was awarded with a German textbook prize (sponsored by private conservative Christian associations), and is used in some public schools. However, the textbook is not accepted by the German Ministry of Education and Cultural Affairs as an official schoolbook, in spite of several lobbying attempts by German creationists. Positive book reviews are largely restricted to periodicals published by Bible-educated Christians. However, the international journal Flora, which is edited by a team of respected plant scientists, published a positive review of this book (Weberling 2002). This fact documents that anti-evolutionism in German-speaking countries has already infiltrated some academic circles.

Darwin’s answer

The discussion concerning the argument from design is as old as evolutionary biology itself. In his autobiography, Darwin treated this issue as follows: “The old argument of design in nature, as given by Paley, which formerly seemed to me so conclusive, fails, now that the law of natural selection has been discovered. We can no longer argue that, for instance, the beautiful hinge of a bivalve shell must have been made by an intelligent being, like the hinge of a door by man” (Barlow 1958). Indeed, modern scientists successfully explain the real world without reference to miracles, “intelligent designers”, or other products of human imagination. If we were to admit “intelligent designers”, “vital forces”, and other spiritual entities, modern science would soon cease to exist (Futuyma 1995; Mahner and Bunge 1997).This is the main reason that scientists reject the modern version of Bible-based creationism under the cover of the currently popular ID rubric.

Charles Darwin provided an appropriate answer to the claims of the creationists of his time when he wrote: “It should be well to bear in mind that by the word ‘creation’ the zoologist means ‘a process he knows not what’” (Darwin 1872). Likewise, the currently popular statement “the designer did it” is no answer, but a synonym for “we believe, but have no evidence”. For those who believe no proof is necessary, discussions between scientists and the dogmatic proponents of ID are difficult and usually do not lead to a consensus.

References

Barlow N, editor. The Autobiography of Charles Darwin. London: Collins, 1958.
Darwin CR. On the Origin of Species, 6th ed. London: John Murray, 1872.
Futuyma DJ. Science on Trial, 2nd ed. Sunderland (MA): Sinauer Associates, 1995.
Gross M. Red head: US-style creationism spreads to Europe. Current Biology 2002; 12 (8): R265–6.
Junker R, Scherer S. Evolution: Ein kritisches Lehrbuch, 5th ed. Giessen (Germany): Weyel Verlag, 2001.
Kutschera U. Designer scientific literature [letter]. Nature 2003 May 8: 423:116.
Mahner M, Bunge M. Foundations of Biophilosophy Berlin: Springer, 1997.
Weberling F. Buchbesprechung [review of Junker and Scherer 2001]. Flora 2002; 197 [4]: 490–1.

About the Author(s): 
Ulrich Kutschera
Institut für Biologie
Universität Kassel
Heinrich-Plett-Strasse 40
34109 Kassel
Germany
kut@uni-kassel.de

Eight Challenges for Intelligent Design Advocates

Reports of the National Center for Science Education
Title: 
Eight Challenges for Intelligent Design Advocates
Author(s): 
Wesley Elsberry, Texas A&M University, and Jeffrey Shallit, University of Waterloo
Volume: 
23
Issue: 
5–6
Year: 
2003
Date: 
September–December
This version might differ slightly from the print publication.
Thus far, "intelligent design" advocates have produced many popular books, but essentially no scientific research. (See, for example, Gilchrist 1997; Forrest 2001.) Future success for the movement depends critically on some genuine achievements. In this article, we provide some challenges for intelligent design advocates, particularly William Dembski.

1 Publish a mathematically rigorous definition of CSI

We challenge Dembski to publish a mathematically rigorous definition of "complex specified information" (CSI) and a proof of the Law of Conservation of Information in a peer-reviewed journal devoted to information theory or statistical inference, taking into account the criticisms in Elsberry and Shallit (2003) and elsewhere.

2 Provide real evidence for CSI claims

Here is a brief catalog of some of the things Dembski has claimed exhibit CSI or "specified complexity":
  1. 16-digit numbers on VISA cards (Dembski 1999: 159);
  2. Phone numbers (Dembski 1999: 159);
  3. "All the numbers on our bills, credit slips and purchase orders" (Dembski 1999: 160);
  4. The "sequence corresponding to a Shakespearean sonnet" (Dembski 2002: xiii);
  5. Arthur Rubinstein's performance of Liszt's "Hungarian Rhapsody" (Dembski 2002: 95);
  6. "Most human artifacts, from Shakespearean sonnets to Durer woodcuts to Cray supercomputers" (Dembski 2002: 207);
  7. Scrabble pieces spelling words (Dembski 2002: 172-3);
  8. DNA (Dembski 2002: 151);
  9. Error-counting function in an evolution simulation (Dembski 2002: 217);
  10. A fitness measure that gauges degree of catalytic function (Dembski 2002: 221);
  11. The "fitness function that prescribes optimal antenna performance" (Dembski 2002: 221);
  12. "Coordination of local fitness functions" (Dembski 2002: 222);
  13. What "anthropic principles" explain in fine-tuning arguments (Dembski 2002: 144);
  14. "Fine-tuning of cosmological constants" (Dembski 2002: xiii);
  15. What David Bohm's "quantum potentials" extract in the way of "active information" (Dembski 2002: 144); and
  16. "The key feature of life that needs to be explained" (Dembski 2002: 180).
We challenge Dembski either to provide a complete, detailed, and rigorous argument in support of his claim that each of the items #1-16 has CSI, or explicitly retract each unsupported claim. Any supporting argument should describe which of the two methods (causal-history-based or uniform probability; see Elsberry and Shallit 2003: 17-21 for further discussion) is used to estimate probabilities, and provide a detailed description of the appropriate probability space, the relevant background knowledge, the rejection region, and the rejection function.

3 Apply CSI to identify human agency where it is currently not known

Thus far CSI has only been used to assert design in two classes of phenomena: those for which human intervention is known through other means, and those for which a precise step-by-step causal history is lacking. We challenge Dembski or other intelligent design advocates to identify, through CSI, some physical artifact - currently not known to be the product of human design - as an artifact constructed by humans. After this prediction through CSI, provide confirming evidence for this conclusion, independent of Dembskian principles.

Along similar lines, apply CSI to identify a suspicious death, currently thought to be from natural causes, as foul play. Furthermore, also provide confirming evidence for this conclusion, independent of Dembskian principles.

We note that Dembski himself has stressed the importance of independent evidence (Dembski 2002: 91).

4 Distinguish between chance and design in archaeoastronomy

The Anasazi, or ancestral Puebloans, occupied what is now the southwestern United States from about 600 to 1300 ce. Several of their buildings - including those at Chaco Canyon, Hovenweep National Monument, and Chimney Rock - have been interpreted as astronomical observatories, with alignments correlated to solstices, equinoxes, lunar standstills and other astronomical events (Malville and Putnam 1989). Using the techniques of The Design Inference, provide a rigorous mathematical analysis of the evidence, determining whether these alignments are due to chance or human design.

Similar challenges exist for the claimed astronomical alignments at Stonehenge (Hawkins 1965; North 1996) and Nabta (Malville and others 1998), and the enigmatic drawings at Nazca in southern Peru. Which of the proposed alignments were designed, and which are pure coincidence?

5 Apply CSI to archaeology

Another interesting question about the Anasazi is the presence of large numbers of pottery shards at certain ruins. Some archeologists have interpreted the number of these shards as exceeding the amount that could be expected through accidents. Use CSI to determine if the pots were broken through accident, or human intent (possibly in support of some religious ritual).

Archeologists have developed methods for determining whether broken flints cracked due to human intervention or not (Cole and others 1978). Attempt to re-derive this classification, or prove it wrong, using the methods of CSI.

Provide a useful means of applying CSI to distinguish early stone tools from rocks with random impact marks.

6 Provide a more detailed account of CSI in biology

Produce a workbook of examples using the explanatory filter, applied to a progressive series of biological phenomena, including allelic substitution of a point mutation. There are two issues to be addressed by this exercise. The first is that a series of fully worked-out examples will demonstrate the feasibility of applying CSI to biological problems. The second is to show that assigning small-scale changes to "chance" and "design" only is indicated for much larger-scale changes or systems already noted as having the attribute of "irreducible complexity". It is our expectation that application of the "explanatory filter" to a wide range of biological examples will, in fact, demonstrate that "design" will be invoked for all but a small fraction of phenomena, and that most biologists would find that many of these classifications are "false positive" attributions of "design".

7 Use CSI to classify the complexity of animal communication

As mentioned in Elsberry and Shallit (2003: 9), many birds exhibit complex songs. We challenge Dembski or other design advocates to produce a rigorous account of the CSI in a variety of bird songs, producing explicit numerical estimates for the number of bits of CSI.

Similar challenges can be issued for dolphin vocalizations, as in providing a definitive test of the "signature whistle" hypothesis (Caldwell and others 1990), and estimation of information of a dolphin biosonar click (to be compared to the information measure suggested by Kamminga [1998]).

8 Animal cognition

Apply CSI to resolve issues in animal cognition and language use by non-human animals. Some of these outstanding issues include studies of mirror self-recognition (Gallup 1970, 1982) and artificial language understanding in chimpanzees (Savage-Rumbaugh 1993), dolphins (Herman and others 1993), and parrots (Pepperberg 1993). We note the use of examples in Dembski's work involving a laboratory rat traversing a maze as an indication of the applicability of CSI to animal cognition (Dembski 1998, 1999, 2002).

These, we feel, are reasonable challenges that Dembski, or others who wish to pursue "intelligent design" as a scientific research paradigm, ought to be eager to meet.

Acknowledgments

We are grateful to Anna Lubiw, Ian Musgrave, John Wilkins, Erik Tellgren, and Paul Vitányi, who read a preliminary version of the longer paper from which this article is derived (Elsberry and Shallit 2003) and gave us many useful comments. We owe a large debt to Richard Wein, whose original ideas have had significant impact on our thinking.

[Adapted with permission from section 12 of Wesley Elsberry and Jeffrey Shallit, "Information theory, evolutionary computation, and Dembski's 'complex specified information'". Available on-line at http://www.talkreason.org/articles/eandsdembski.pdf.]

References

Caldwell MC, Caldwell DK, Tyack TL. Review of the signature-whistle hypothesis for the Atlantic Bottlenose Dolphin. In: Leatherwood S, Reeves RR, editors. The Bottlenose Dolphin. San Diego (CA): Academic Press, 1990. p 199-234.

Cole JR, Funk RE, Godfrey LR, Starna W. On criticisms of "Some Paleolithic tools from northeast North America": rejoinder. Current Anthropology 1978; 19: 665-9.

Dembski WA. The Design Inference: Eliminating Chance Through Small Probabilities. Cambridge: Cambridge University Press, 1998.

Dembski WA. Intelligent Design: The Bridge Between Science & Theology. Downers Grove (IL): InterVarsity Press, 1999.

Dembski WA. No Free Lunch: Why Specified Complexity Cannot Be Purchased Without Intelligence. Lanham (MD): Rowman & Littlefield, 2002.

Elsberry W, Shallit J. Information theory, evolutionary computation, and Dembski's "complex specified information. 2003. Available on-line at http://www.talkreason.org/articles/eandsdembski.pdf.

Forrest B. The wedge at work: How intelligent design creationism is wedging its way into the cultural and academic mainstream. In: Pennock RT, editor. Intelligent Design Creationism and Its Critics. Cambridge (MA): MIT Press, 2001. p 5-53.

Gallup Jr GG. Chimpanzees: self-recognition. Science 1970; 167: 86-7.

Gallup Jr GG. Self-awareness and the emergence of mind in primates. American Journal of Primatology 1982; 2: 237-48.

Gilchrist GW. The elusive scientific basis of intelligent design theory. Reports of the National Center for Science Education 1997 May/Jun; 17 (3): 14-5.

Hawkins GS. Stonehenge Decoded. New York: Doubleday, 1965.

Herman LM, Kuczaj SA, Holder MD. Responses to anomalous gestural sequences by a language-trained dolphin: evidence for processing of semantic relations and syntactic information. Journal of Experimental Psychology 1993; 122: 184-94.

Kamminga C, Cohen Stuart AB, de Bruin MG. A time-frequency entropy measure of uncertainty applied to dolphin echolocation signals. Acoustics Letters 1998; 21 (8): 155-60.

Malville JM, Putnam C. Prehistoric Astronomy in the Southwest. Boulder (CO): Johnson Books, 1989.

Malville JM, Wendorf F, Mazar AA, Schild R. Megaliths and Neolithic astronomy in southern Egypt. Nature 1998; 392: 488-91.

North JD. Stonehenge: Neolithic Man and the Cosmos. New York: HarperCollins, 1996.

Pepperberg IM. Cognition and communication in an African Grey Parrot (Psittacus erithacus): Studies on a nonhuman, nonprimate, nonmammalian subject. In Roitblat HL, Herman LM, Nachtigall PE, editors. Language and Communication: Comparative Perspectives. Mahwah (NJ): Lawrence Erlbaum, 1993. p 221-48.

Savage-Rumbaugh ES. Language learnability in man, ape, and dolphin. In Roitblat HL, Herman LM, Nachtigall PE, editors. Language and Communication: Comparative Perspectives. Mahwah (NJ): Lawrence Erlbaum, 1993. p 457-73.

About the Author(s): 
Wesley Elsberry
c/o NCSE
PO Box 9477
Berkeley CA 94709-0477

Jeffrey Shallit
Department of Computer Science
University of Waterloo
Waterloo, Ontario N2L 3G1
Canada

Evolution: Still Deep in the Heart of Textbooks

Reports of the National Center for Science Education
Title: 
Evolution: Still Deep in the Heart of Textbooks
Author(s): 
Skip Evans
Volume: 
23
Issue: 
5–6
Year: 
2003
Date: 
September–December
This version might differ slightly from the print publication.
To watchers of the creationism/evolution controversy, the textbook adoption process in Texas is not only familiar but also important. Evolution is historically among the most contentious areas in the process. Moreover, decisions on textbooks in Texas affect far more students than just those in the Lone Star State. Because Texas is the second largest textbook market in the country, behind only California, textbooks adopted there will also be offered in states around the country. The stakes are high for the publishers, too: the state is expected to spend 570 million dollars on new textbooks, of which 30 million dollars is for biology textbooks.

As the adoption process for biology textbooks began in early 2003, the ranks of those vocally opposed to evolution education swelled. For decades, Mel and Norma Gabler’s Educational Research Analysts — “a conservative Christian organization that reviews public school textbooks submitted for adoption in Texas” which places “scientific flaws in arguments for evolution” at the top of its list of concerns (http://members.aol.com/TxtbkRevws/about.htm) — has urged the Texas Board of Education to minimize evolution and even to include creationism in the textbooks adopted for use in the state (see, for example, RNCSE 1999 Jan/Feb; 19 [1]: 10). In 2003, the Gablers were joined by a host of homegrown creationists as well as by the Discovery Institute, the institutional home of “intelligent design”, in seeking to undermine the treatment of evolution in the biology textbooks under consideration.

Anti-evolutionists faced an uphill battle from the start

First, the state science standards, adopted by the Texas Education Agency (TEA) in 1997, require students to learn about evolution. There is no mention of creationism or “intelligent design” in the standards. The state standards form the basis of the Texas Assessment of Knowledge and Skills test, which students must pass in order to graduate from high school. Consequently, teachers could compellingly argue that it would be counterproductive to minimize evolution, or to introduce creationism, in the biology textbooks.

Second, whereas in the past the board was allowed to edit textbooks for content, in 1995 the state legislature limited the board’s power. With regard to textbooks, the board is now allowed only to enforce three requirements:

  • they must satisfy each element of the Texas Essential Knowledge and Skills (TEKS) standards;
  • they must have good bindings;
  • they must be free of factual errors.
There were no complaints about the bindings. Anti-evolutionists were keen, however, not only to allege that the textbooks were laden with factual errors, but also to claim that the books failed to satisfy the TEKS standards — in particular TEKS requirement 112.43c(3)A, which states that students should “analyze, review, and critique scientific explanations, including hypotheses and theories, as their strengths and weaknesses using scientific evidence and information.” The language of “3(A)” (as it became known) lent itself to anti-evolutionist calls to “teach the controversy”.

Such claims contradicted the assessment of a 12-member review panel commissioned by the Texas Education Agency, which in June decided that the textbooks were both scientifically accurate and in conformity with the TEKS standards. Anti-evolutionists, including board members David Bradley, Terri Leo, and Don McLeroy, were later to allege that the TEA incorrectly instructed the panel — perhaps intentionally, Bradley speculated (see, for example, the Galveston County Daily News 2003 Jul 20, available on-line at http://www.galvnews.com/print.lasso?ewcd=97dd2da2a536a818). Of course, the final decision on whether to approve the textbooks rested with the board.

Throughout the process, news stories as well as letters to the editor, op-ed pieces, and press releases from all sides of the controversy filled Texas newspapers; for reasons of space they are not discussed here (although Alfred Gilman’s op-ed, signed by seventeen members of the National Academy of Science and/or the Institute of Medicine, including four Nobel laureates, is reprinted on p 8). Many of these pieces are archived on the web site of Texas Citizens for Science: http://www.txscience.org.

The July hearing

On July 9, 2003, at the first of two scheduled public hearings, nearly three dozen speakers addressed the board, almost all of them speaking in defense of the 11 biology textbooks submitted. (NCSE executive director Eugenie C Scott and postdoctoral scholar Alan Gishlick attended as observers.) “I’m here to keep outside forces from removing science from science books”, said David Hillis, Professor of Biology at the University of Texas at Austin, and president of the Society for the Study of Evolution (San Antonio Express News 2003 Jul 10; available on-line at http://news.mysanantonio.com/story.cfm?xla=saen&xlb=180&xlc=1023426).

Many of the speakers were reacting to a critique of the textbooks submitted by the Discovery Institute (http://www.discovery.org/articleFiles/PDFs/TexasPrelim.pdf). The critique, based largely on Jonathan Wells’s Icons of Evolution (Washington [DC]: Regnery, 2000), graded the textbooks on their discussion of 4 “icons”: the Miller-Urey experiment, the Cambrian explosion, Haeckel’s drawings of vertebrate embryos, and industrial melanism in peppered moths. Only one textbook passed, with a grade of C–.

Two fellows of the Discovery Institute’s Center for Science and Culture testified at the June hearing: Raymond Bohlin, executive director of Probe Ministries, and Francis J Beckwith, newly appointed as Associate Professor of Church–State Studies at Baylor University. Consistent with the Discovery Institute’s recent tactics, Bohlin insisted that he was not calling for “intelligent design” to be added to the textbooks or for evolution to be removed. Instead, he told CNN, “Every theory has its weaknesses, has its problems, and evolution seems to be the one theory in the textbooks that just isn’t treated that way” (2003 Jul 9). Steven Schafersman, president of the pro-evolution education grassroots group Texas Citizens for Science (see RNCSE 2003 May–Aug; 23 [3–4]: 9), was unimpressed: “They’re trying to get in anti-evolution material by calling it a weakness” (Houston Chronicle 2003 Jun 10).

A complete transcript of the July hearing is available on-line at http://www.tea.state.tx.us/textbooks/adoptprocess/july03transcript.pdf.

Between the July hearing and the September hearing, the BOE received reams of written comments on the textbooks, to which the publishers were required to respond. For example, in his critique of Biology, published by Holt, Rinehart & Winston, Mark Ramsey of the newly formed anti-evolutionist group Texans for Better Science Education asserted that a recent article in a popular journal (RO Prum and AH Bush, “Which came first, the feather or the bird?” Scientific American 2003 Mar; 288: 84–93) “fully discredits the dino-to-bird idea.” The publisher replied that “[t]he hypothesis that birds evolved from dinosaurs continues to have strong support in the scientific community and has been strengthened recently by new fossil finds in China”, and noted that Prum and Bush accept the evolution of birds from dinosaurs, quoting the same article’s acknowledgment that “birds are a group of feathered therapod dinosaurs that evolved the capacity of flight” (http://www.tea.state.tx.us/textbooks/adoptprocess/2003pubresponses.pdf). In the end, the publishers held the line, agreeing to no changes that would materially weaken the treatment of evolution in their textbooks.

The September hearing

On September 10, at the second public hearing, a standing-room-only crowd was in attendance. More than 160 people signed up to speak before the board, and the testimony continued into the wee hours. Supporters of quality science education, including members of NCSE, Texas Citizens for Science, and the Texas Freedom Network, which led the statewide organizing effort; scientists from the University of Texas at Austin and around the state; educators, including many members of the Texas Association of Biology Teachers; and concerned parents, clergy, and citizens in general were out in force — many wearing their “Don’t mess with textbooks” T-shirts. (The clever variation on the “Don’t mess with Texas” anti-litter slogan, which became the pro-evolution education movement’s unofficial motto, was due to NCSE’s Archives Project Director, David Leitner; see p 22.)

Samantha Smoot, the executive director of the Texas Freedom Network, told the board, “The weaknesses of evolution alleged here today are founded on ideology, not science. ... There’s really no debate about any of this in the scientific community.” Her view was confirmed by the testimony of research biologists such as Andrew Ellington and Matthew Levy of the University of Texas at Austin, whose testimony was a devastating critique of the Discovery Institute’s assessment of the biology textbooks’ treatment of scientific research into the origin of life.

Steven Weinberg, Professor of Physics at the University of Texas at Austin, addressed the common criticism that evolution is “just a theory” by remarking that his theory of the unified weak and electromagnetic interaction between elementary particles won him the 1979 Nobel Prize for Physics. He added that the existence of phenomena unexplained by a given theory is not, in his view, a “weakness”. He also reminded the BOE:

[Y]ou’re not doing your job if you let a question like the validity of evolution through natural selection go to the students, any more than a judge is doing his job or her job if he or she allows the question of witchcraft to go to the jury. ... I think it’s clear that the reason why the issue was raised with regard to evolution is because of an attempt to preserve religious beliefs against the possible impact of the Theory of Evolution.
The Reverend Roger Paynter of Austin’s First Baptist Church testified, “It is my deep conviction that creation flows from the hand of a creator God. But that is a statement of faith and not something that I or anyone else can prove in a scientific experiment. To lead children to believe otherwise is a disservice to them.”

Creationists, for their part, were vocal, too. Mark Ramsey, of Texans for Better Science Education — who is also the secretary and a board member of the Greater Houston Creation Association — said, “I was indoctrinated, some would say brainwashed, to believe that evolution was as proven as gravity. ... Today, over two decades later, many of us now know better.”

Out-of-state witnesses, including several associated with the Discovery Institute, were not allowed to testify during the hearing; they were, however, permitted to make presentations to board members after the hearing adjourned and to submit written testimony. NCSE’s Alan Gishlick and Eugenie C Scott and NCSE member Robert T Pennock stressed the importance of a sound presentation of evolution in textbooks.

A complete transcript of the September hearing is available on-line at http://www.tea.state.tx.us/textbooks/adoptprocess/sept03transcript.pdf; the passages of testimony above are quoted from it.

Following the hearing, in October the Discovery Institute sent the textbook publishers and members of the board a document intended to support, reiterate, and extend its criticism of the textbooks under consideration. Literally hundreds of pages long, the document contained excerpts from scientific publications as well as the Discovery Institute’s interpretation of them. Evidently attempting to pre-empt criticism of the sort received by its “Bibliography of supplementary resources for Ohio science instruction” (see RNCSE 2002 Aug/Sep; 22 [4]: 12–18, 23–24), the document warned of the likelihood of critics “falsely accus[ing] Discovery Institute of misrepresenting the scientific literature by misquoting or quoting out of context.”

A less lofty appeal to the board came from Columbine Redemption, a nonprofit organization founded by Darrell Scott, whose daughter was murdered in 1999 at Columbine High School in Littleton, Colorado. In a press release with the headline “Bad science produces bad consequences” (2003 Oct 13; available on-line at http://www.strengthsandweaknesses.com/D.Scott.Oct.13.PR.2.pdf), Columbine Redemption alleged that evolution education was responsible for the Columbine massacre and urged the board to “reject proposed Texas biology books that do not teach weaknesses of evolution as required by Texas law.”

The November vote

As the November vote approached, the publishers held firm, making only minor editorial changes, but none of the overhauls requested by anti-evolutionists. “In keeping with their commitment to provide students with the best possible science education, biology textbook publishers have stood up to political pressure,” said the Texas Freedom Network’s Samantha Smoot. The Discovery Institute, however, claimed that the changes were in response to its critique and vowed to continue to pressure the publishers. “We will be seeking more changes in the textbooks,” said John West, associate director of the Discovery Institute’s Center for Science and Culture (Dallas Morning News 2003 Oct 30; available on-line at http://www.dallasnews.com/sharedcontent/dallas/politics/state/stories/103103dntextextbooks.10ff7.html).

Two public letters to the board that appeared in early November are of particular interest.

On November 1, the American Institute of Physics released a statement signed by more than 550 Texas scientists and educators denouncing attempts to undermine the treatment of evolution in the textbooks: “Any dilution in textbooks of the overwhelming scientific evidence for evolution should sound an alarm to every parent and teacher.” In addition to the AIP, the American Geological Institute, the American Astronomical Society, and the American Institute of Biological Sciences and several of its member societies, also encouraged their members in Texas to sign the statement. The statement and a list of signatories are available on-line at http://www.txscience.org/files/texas-scientists.pdf.

On November 4, David Hillis and Martin Poenie, like Hillis a biologist at the University of Texas at Austin, sent a letter to the board urging that all 11 textbooks be adopted without changes. Poenie’s co-authorship was noteworthy because his name appeared on the Discovery Institute’s “A scientific dissent from Darwinism” (see RNCSE 2001 Sep–Dec; 21 [5–6]: 22–3) and again, without Poenie’s authorization, on a similar statement entitled “40 Texas scientists skeptical of Darwin” and because he previously wrote a letter to the board arguing that “Darwinian (hyperdarwinian) mechanisms are not the only ones molding the evolutionary history of life and that we should be free to consider alternative non-darwinian mechanisms of change”. In his November letter, however, Poenie explained, “that letter was not intended to oppose basic evolutionary biology or to support poor teaching or coverage of that topic.” Hillis and Poenie went on to say, “We believe that all of the books conform to the TEKS standards and should be approved and placed on the conforming list of textbooks” (their letter is available on-line at http://www.txscience.org/files/ut-austin-profs2.htm).

On November 6, at the first day of a 2-day meeting, a motion to vote on the books individually was defeated 11–4, thwarting the plans of anti-evolutionist members of the board to approve only the textbooks that, in their judgment, presented evolution undogmatically (Fort Worth Star-Telegram 2003 Nov 6; available on-line at http://www.dfw.com/mld/dfw/7198627.htm). A majority of the board was evidently ready to end the discussion, the Los Angeles Times reported (2003 Nov 7):

The chairwoman of the board, Geraldine Miller of Dallas, was twice reduced to slamming her fist down as a conservative wing of the panel tried repeatedly to reject most of the books.

After tense arguments, a board member voting with the majority, Joe Bernal of San Antonio, urged Miller to simply stop recognizing people who were holding up their hands to speak. That way, he said, she wouldn’t “prolong this agony.”

Eventually, in a preliminary vote conducted on the same day, the board voted 11–4 to approve the books. In both votes, David Bradley, Terri Leo, Gail Lowe, and Don McLeroy were in the minority.

On November 7, the board conducted its final vote, approving all 11 textbooks for use in Texas’s public schools. (At the time of writing, the minutes of the meeting are not available, and it is unclear from the news reports what the exact tally was.) The vote, David Hillis said, “means we will be able to provide good quality biology textbooks to the students of Texas” (UPI wire, 2003 Nov 7). “This is great news for the children of Texas,” said Samantha Smoot. “The board sent a clear message that educational and scientific standards come first for Texas schools, not the ideological preferences of a few people” (Austin Chronicle 2003 Nov 14; available on-line at http://www.austinchronicle.com/issues/dispatch/2003-11-14/pols_feature8.html).

The Discovery Institute, for its part, declared victory, in a press release with the headline “Textbook reformers see last-minute victory in Texas decision” (2003 Nov 7; http://www.discovery.org/scripts/viewDB/index.php?command=view&id=1634&program=News-CSC). Noting that TEA Chief Deputy Commissioner Robert Scott promised to address any remaining factual errors in the books before they arrive in Texas schools, the Discovery Institute implied that its criticisms of the book were still in play, and later a spokesperson was explicit: “[W]e were happy to hear ... Scott publicly pledge that publishers must address the errors that Discovery had previously identified” (Science & Theology News 2003 Dec; 4 [4]: 10). However, a TEA spokesperson explained that the sorts of errors that are corrected after a book is accepted are usually minor, involving such minutiae as dates, pagination, and punctuation (UPI wire, 2003 Nov 7).

Students in Texas’s public schools will learn their biology from textbooks in which the treatment of evolution is uncompromised. NCSE is proud to have worked closely with the dedicated Texans who helped to ensure victory, including not only NCSE members but also the members and staff of the Texas Freedom Network, Texas Citizens for Science, and the Texas Association of Biology Teachers. Thanks and congratulations.

About the Author(s): 
Skip Evans
NCSE
PO Box 9477
Berkeley CA 94709-0477
evans@ncseweb.org

What Design Looks Like

Reports of the National Center for Science Education
Title: 
What Design Looks Like
Author(s): 
Mark Isaak
Volume: 
23
Issue: 
5–6
Year: 
2003
Date: 
September–December
This version might differ slightly from the print publication.
You know, people think it must all be very easy, creating.
They think you just have to move on the face of the waters and
wave your hands a bit. It’s not like that at all. —Terry Pratchett, Eric


"Life looks designed" is a common refrain among a variety of creationists. The claim is intuitively appealing because we have experience with design. For most people, that is the only way they know for making a functional machine. Since design is the only explanation they can imagine, they naturally consider it the best explanation. To this extent, "looks designed" is just an argument from ignorance. But many creationists further claim that this appearance of design is objective, can be (and, some say, has been) demonstrated scientifically, and therefore is suitable for teaching in public schools (for example, Dembski 2001a). The little evidence they present, though, is maddeningly vague. In most cases, the supposed evidence for design consists simply of pointing to various examples from natural history and saying, "Look, can’t you see it?" Typically, this is accompanied by the usual creationist attacks on evolution and the claim, implicit or explicit, that design is the only alternative. Often there are vague analogies with human artifacts such as watches or writing, but never with objective standards of comparison. In design theory, "looks designed" has been left to the imagination of the believer.

When done properly, though, the "looks designed" method, or the method of analogy, is an effective method for detecting design. In fact, it is almost always how we recognize design in our daily lives. We learn through direct experience that some things are designed — by seeing the things made — or through testimony of the designers themselves. Most artifacts, though, we recognize as designed because they look like things that we already know are designed.

Analogy is used in science, especially in fields such as archaeology and forensics, to distinguish design from non-design. For example, archaeologists can tell whether a flint was broken deliberately or naturally because flints known to be worked by humans differ from naturally broken flints in features such as fracture angle (Cole and others 1978). SETI researchers, in searching for non-human design, use analogy by assuming human-like properties of extraterrestrials — namely, an interest in communicating and a desire to do so efficiently. And analogy is explicitly accepted, even promoted, by some creationists as a valid method of determining design (Moreland 1994; Thaxton 2001). Analogy to known design should be one way to detect design that evolutionists and creationists can agree upon.

Of course, the analogy method can only provide comparisons with designs produced by humans, since those are the only designs with which we have significant experience. Other design arguments suffer a fatal weakness: Without knowing anything about a designer, we cannot say anything about what to expect from one (Hume 1779; Sober 2003). Detecting a certain pattern does not indicate a designer until it can be demonstrated that the designer produces such a pattern, and this task would seem to be impossible when dealing with potentially supernatural designers. By assuming at least some commonality between humans and the unknown designer, we can avoid that problem. The analogy argument, despite the weakness of its assumption of human-like designs, is one design argument which leads somewhere other than in circles. To use this method, though, we must first say what design looks like.

Determining what design looks like is no trivial matter. A communications satellite, a drainage ditch, OPEC, a mathematical proof, a jelly bean, false teeth, a limerick, the controlled burn of a forest, and shampoo have little in common, but all are designed. Probably no single criterion can ever describe them all. Still, design does have some properties that are fairly general. I examine some of these properties below and consider how they compare with what we see in life. I also consider other properties that creationists claim as indications of design. There are some similarities and some differences between life and design, but as we shall see, even the similarities argue against design as a scientific theory.

Structure

Probably the most obvious aspect of designed things is an intermediate level of structural order. Unfortunately, this sort of structure is difficult to characterize quantitatively, but its quality is apparent. Almost all designs have an arrangement that is neither very regular nor very random, but instead is between those extremes. There are exceptions, of course; a brick wall is highly ordered, and a stew is very disordered. Most designs, however, are neither uniform nor random, neither regular nor chaotic. Such an intermediate level of structure arises as a consequence of design. Objects that are too highly ordered are limited in their applications by their simplicity. Objects that are too chaotic are generally more expensive to produce, or their disorder keeps them from fitting and functioning well with other designs.

An intermediate level of structure plainly exists also in life. It is probably the most important characteristic people have in mind when they say that life looks designed. It is related to concepts of information, so it may have inspired some creationist arguments about information theory. Since there is no commonly accepted word for this property, and since it is hard to characterize, it is not surprising that creationist claims about design are vague and ill-formed. Despite the lack of rigorous description, though, we can be fairly confident that having an intermediate level of structure is an important quality shared by both design and life.

This is not enough to conclude that life looks designed, though, because an intermediate level of structure can arise naturally, too. Such structure can be found in molecules, cave formations, the Northern Lights, and Jupiter’s atmosphere, to give just a few examples. Structure arises spontaneously from a variety of processes; in fact, it takes only a couple of seconds for structure to appear in a candle flame. With regard to life, there is evidence that structure not only can arise naturally from ordinary processes, but perhaps should be expected from it (Kauffman 1993; Adami and others 2000).

Simplicity

An underappreciated aspect of design is simplicity. Although many people associate design with complexity, almost all designs aim for maximum simplicity. (Complexity is another concept whose exact meaning is hard to pin down. As I use it here, greater complexity indicates that something is generally harder to understand; simplicity, of course, is the opposite.) Simplicity is important in design because simple designs are easier to invent, easier to implement, easier to modify, and usually easier to use. A good design is a simple design.

Of course, most designs require a certain amount of complexity. A home computer, for example, would not be able to do much if it consisted of nothing more than a solid block of silicon. (Although an advanced civilization could reputedly do a lot with a rectangular black obelisk.) It is in such seemingly complex designs, though, that the principle of simplicity is most important. A computer is actually a fairly simple arrangement of components — CPU, memory, various peripherals, and wires connecting them — with fairly simple interfaces among the components. Each of the components, in turn, is a simple arrangement of sub-components, which may themselves consist of smaller sub-components, and so on until the simplest level is reached. In this way, each component, at whatever level, can be treated as a separate, almost independent unit, making it relatively easy to understand. Without such a simply-connected modular structure, each piece would have the potential to affect any other piece, and considering all the possible interactions would be impractical to say the least.

Simplicity is not what we see in life. Although most life has modular structure — that is, organisms made up of organs made up of cells made up of organelles — the complexity of life is far greater than we see in design. The individual parts are still very complex, the interfaces between parts are very complex, and individual parts can usually directly affect a large number of other parts. This complexity is compounded by the fact that organisms change a great deal over their lifetimes. After decades of work, biologists have scarcely begun to understand how a human body works, much less how all the various organisms in an ecosystem work and interact. A good illustration of the complexity of life is the difficulty of designing a drug with no unwanted side-effects. But I need not elaborate; creationists themselves cite complexity as one of the hallmarks of life. Nothwithstanding disagreement over its source and significance, the complexity of life is another things that evolutionists and creationists can agree upon.

Although simplicity is a goal, complexity can still enter into design in some ways. One way that complexity enters into design is through the process of modification. If a change is made that renders part of a system obsolete, it is often easier to leave in some or all of the old parts, which then add unnecessary complexity to the design. Modification also adds complexity when changes are jury-rigged onto the existing structure rather than incorporated into the fundamental design. For example, some fixes to the Y2K bug involved checking the 2-digit year and trying to determine which century was intended, rather than the simpler and more correct, but much harder to do retroactively, fix of using 4-digit years. Such complexity is not necessarily bad design, either, since a frequent requirement of design is to get a working product out quickly, even if it is not as elegant as possible. Such complexity seems to appear in life, too, in the form of vestigial and jury-rigged features such as the appendix and the panda’s thumb. Evolutionists cite these as examples of poor design, which they may be from the standpoint of an omnipotent creator, but they are traits that life shares in common with our experience of design.

In summary, although creationists frequently cite complexity as evidence of design, simplicity would be the real evidence. Complexity can enter design through careless modification, but again such complexity can often be recognized as such, as with jury-rigged or vestigial parts. Besides, such complexity is what we expect from evolution.

Finally, design can become complex through evolutionary algorithms, which use repeated cycles of reproduction of initially random designs, selection from among them, and slight modifications and recombinations of the results (Davidson 1997). Such a design procedure does not need to minimize complexity because it always treats the design as a whole. The final design is extremely difficult to understand, but there is no need to understand it. The use of such a design method by humans is still in its infancy, but if it becomes widespread, we may then be justified in saying that life’s complexity looks designed. Of course, at that point "designed" and "evolved" become synonyms.

Reproduction

One of the defining features of life is that life reproduces itself. This is very different from designed things, which, with very few exceptions, are designed so that their production is separate from their other functions. A separate manufacturing process offers extreme benefits of efficiency for the simple reason that a manufacturing plant does not need to be built into each artifact. The few designed things that do reproduce themselves, such as computer viruses, can do so only because the production process and necessary resources are trivially cheap. And even the self-replicating human designs differ from life in that they do not go through the growth and development that living things experience before they can reproduce.

Let us suppose, along with Paley (1802, ch 2), that someone on a heath found a watch that "possessed the unexpected property of producing, in the course of its movement, another watch like itself." Paley said, "The first effect would be to increase his admiration of the contrivance, and his conviction of the consummate skill of the contriver." But would it? Such a watch, even with today’s technology, would be far too large to wear. Even if it were small enough, it would still be far larger than necessary. What’s more, the watch would need some way of obtaining raw materials, which would mean either the watch leaves its owner from time to time, or it manipulates its owner to bring it and the materials together. We could certainly admire the consummate skill of the contriver, but our admiration of the contrivance would be severely mitigated by the unnecessary impositions that reproduction would require. Reproduction may find some uses in design; for example, a self-reproducing factory for ordinary watches could conceivably produce an endless supply of useful watches with little requirement for labor. However, there is also a demand for non-reproductive manufacturing of designed items. Almost all designs that people are familiar with today would be useless if they had to include the capability of reproduction.

Repair of designed objects also has to come from the outside. The same economies that keep reproduction out of design also prohibit self-repair. Life forms, in contrast, include the ability to repair minor and in some cases extreme damage. This difference between life and design is so familiar that I need not go into further detail.

Form and Function

Another aspect of design is that form tends to follow function. A designer looking for a component to perform a particular function will, when possible, use an existing design rather than inventing a new one. When a useful innovation is introduced, it quickly gets applied to a wide variety of uses. This leads to the property that similar parts fulfill a common function even on very different products. For example, zippers of essentially the same design are found on clothing, tents, luggage, and other things. The same basic engine design can be found on motorcycles, motor boats, and lawnmowers. Some parts, such as screws, resistors, and software libraries, are even standardized so as to make it easy to use them in a wide variety of applications.

Life, in contrast, shows much less connection between form and function. Different taxa achieve similar functions with very different forms. For example, bats, birds, insects, and pterosaurs all have quite different wing anatomies. In different groups of insects, various forms of hearing organs are found in at least 11 different places on the body (Yack and Fullard 1993; Hoy and Robert 1996). And similar forms in life do not imply similar function. A human hand, a bat’s wing, a mole’s paw, a dog’s paw, and a whale’s flipper all have the same basic bone structure, despite their different functions of grasping, flying, digging, running, and swimming.

This difference between life and design is most apparent in the fact that life arranges naturally into a nested hierarchy, but design does not. With life forms, taxa defined by major features fall either entirely inside or entirely outside other taxa. This property led to the familiar hierarchical classification begun by Linnaeus. The hierarchy is not perfect, but it is a natural hierarchy in that there are enough common traits to make most of the groupings obvious. With designed things, on the other hand, overlap is the norm. Although it is possible to form a nested hierarchy of designed things (indeed, it is possible to arrange any set of different objects in a nested hierarchy), there is no natural nested hierarchy. Consider sports, for example. There are lots of different features one could consider in classifying various sports: team sports, sports played on a rectangular field, sports played with a ball, and so on. However one classifies them, though, the groups overlap. The category of sports itself overlaps with other categories such as combat, art, and fitness. No obvious classification scheme presents itself. In fact, the only classification scheme that is commonly used with designed things generally is alphabetical order.

Trial and Error

Creationists seem to think of design as a single event that is done quickly and is over with. Even those creationists who see creation spread over time seem to envision many individual creation events. Real design, however, is a process. Designs are rarely completed in one attempt. They must be tested and modified to account for unforeseen consequences. Testing is done at many stages, from the first conception to field tests of the final product. Entire industries are devoted to the testing of structures, vehicles, computer systems, and other designs. All of these tests (if they are effective) result in information that guides the subsequent design. Furthermore, designers draw upon the experience of previous designers. When an architect designs a simple bridge or building, the process may seem straightforward, but that design is based on an education that comes from literally centuries of trial and error by earlier architects and builders (Petroski 1982).

This last point raises another observable property of design. Because designs are so often built upon previous designs, designs evolve over time, with new designs appearing as modifications of previous ones. This, of course, is also a property of life, as the fossil record shows. However, because people can intelligently combine a wide variety of innovations and other features, designs can change rapidly over time. Very few human designs have been around for more than a few thousand years, and most do not last nearly that long. Furthermore, the more complex designs are generally the shorter-lived. Although life changes over time, it does not do so nearly as fast as we see in human-driven modifications in design.

Purpose and Function

Creationists often claim that purpose indicates design. But purpose is hard to specify without knowing the designer, and it is often conflated with function. Purpose, as I use it here, is what someone intends a thing to be used for; function is what the thing actually does. The intent is useless for determining design, because it can be whatever anyone proposes, and the same object can, and often does, have different purposes for different people. Purposes often conflict. For example, a lynx’s purpose for a rabbit is likely quite different from that of the rabbit itself. Undesigned things often have purpose. For example, a stone need not be designed for people to give it a purpose as a pounding stone. The designer of an object can design a purpose into it, but others can find their own uses, as any MacGyver rerun shows.

Function also fails to indicate design for many of the same reasons. People can find functions other than what the designer intended. And functions can change in a heartbeat, as when the muscles of the fleeing rabbit become food for the lynx. Most importantly, undesigned things can have function — in fact, we expect function to evolve (see below). In short, purpose and function are too variable and subjective, and do not discriminate designed items from undesigned items.

Complexity-Specification

Dembski proposes to recognize some design through a property he calls complexity-specification. If a pattern is highly improbable and yet matches a specification that was given beforehand, then that pattern has complexity-specification and, he says, must have been designed (Dembski 1999). For example, if I deal a hand of 13 cards that exactly matches an example bridge hand you saw in the newspaper that morning, you can be confident the deal was designed to come out that way. To detect this sort of design, Dembski proposes an "explanatory filter" which, if it rules out regularity (natural law) and chance, finds design as the only alternative (Dembski 1998). But because complexity-specification is defined simply as the lack of known causes, it is nothing more than an argument from ignorance given formal mathematical form. It does not say a thing about the properties of design.

However, it is instructive to consider complexity-specification at greater length anyway. Specification means matching something that was given elsewhere. Complexity (in Dembski’s unorthodox usage) simply means unlikelihood of occurring by chance in its observed configuration. By these definitions, patterns of complex specification can be produced naturally, too, with chance providing complexity and regularity acting selectively to reduce it. Evolution proceeds in large part by random mutations causing variation and natural selection winnowing that variation according to constraints of the environment. The mutations produce a form of complexity, and natural selection acts as a specifier. Since evolution includes complexity (mutations) plus specification (selection), it is only to be expected that evolution would produce complexity-specification in evolved life.

It is because Dembski’s filter fails to consider this combination of regularity and chance acting together that it will inevitably group together the products of evolution with design. Dembski claims that natural selection cannot create complexity-specification, but he only argues against the straw-man of creating it de novo. Even he admits that natural selection can bring the specification in from the environment (Dembski 2001b). And this, after all, is what natural selection is all about.

Actually detecting the results of specification, though, can be a tricky business. Ideally, we conclude specification when an observation matches a complex pattern that was given earlier. This does not work, though, when the observation comes before we know what we are supposed to match it with. In such cases, the "specification" comes from finding a pattern in part of the object and seeing the same pattern carry through the rest of the object. (This is the general procedure that Dembski suggests. To the best of my knowledge, he has never provided a way of detecting complexity-specification in life that is objective and practical enough for two people to get the same results.) In other words, complexity-specification implies, in practice, some amount of regularity, but not so much that the word "complex" no longer applies. This just describes the intermediate level of structure discussed in a previous section. And since this property originates via both natural processes and design, it cannot be used to distinguish between them.

Functional Integration

Another property that has been taken to indicate design is functional integration, or multiple parts working together to produce a particular function or end (Lumsden, quoted in Alters 1995). This property seems intuitively appealing because much design consists of assembling parts to create a particular function. But functional integration may be claimed even when origins are known to be natural. For example, the climate of the Mississippi Basin is determined by the Rocky Mountains, the Gulf of Mexico, trade winds, and other factors. Since the climate is a functional end (it allows an ecology suitable for certain organisms) produced by multiple factors, it fits the definition of functional integration. And in fact this example was used as an argument for design by the 19th-century creationist George Taylor (Morton 2001). Obviously, though, any arrangement of physical factors, whether designed or not, is going to create some kind of climate. Since functional integration arises from non-design, it cannot reliably indicate design.

It may still be argued that functional integration that arises naturally is not necessarily very functional (the inland Antarctic climate is not terribly hospitable) or very integrated (we do not often think of trade winds, mountains, and a gulf as a single unit). Again, however, functional integration is a quality of evolution as well as of design. Evolution cannot proceed without units to reproduce. "Unit" already implies some integration, and reproduction is itself a function. Furthermore, survival entails many additional functions such as finding food and escaping predators. Natural selection would ensure that such functionality and integration are maintained. So functional integration indicates evolution at least as much as it indicates design.

Fine Tuning

Although it applies not to life but to the universe around it, the fine-tuning argument for design deserves some consideration here. This argument claims that many physical constants and other features of the universe fall in the only narrow range that would allow life to be possible — so many features, in fact, that the combination could not be explained by chance and must be designed (Barrow and Tipler 1986; Ross 1994). Others have shown the problems with this argument (Le Poidevin 1996; Stenger 1997). Of interest here is a prior question, namely whether fine-tuning indicates design in the first place.

Fine-tuning is an aspect of design, of course; the term even comes from engineering. Designing components to mesh well with other components or with the outside environment is a common necessity. However, designers are not entirely stupid. When they fine-tune, they tune the parts that are easy to change. If parts are added later that have not been built yet, they fit the new parts to the existing design, making the fine-tuning of the new parts part of designing them. Fine-tuning is done to malleable parts and parts that come later.

This is very different from the fine-tuning argument from "intelligent design theorists". The physical constants of the universe, to all appearances, are not easily changeable, if they are changeable at all. Life, on the other hand, is extremely adaptable. Furthermore, life appeared much later than the universe and exists in only a minuscule fraction of it. The universe we see is compatible with a universe designed in fine detail to support life as we know it (design theory is compatible with anything), but an argument based on analogy to design would claim that life is fine-tuned to the universe, not vice versa. The claim that the universe was fine-tuned for life is the very opposite of a design argument.

Conclusions

Table 1 ( p 34) shows a summary of the similarities and differences between life and design. Although there are a number of similarities, the differences are large and important. In particular, life’s growth and reproduction alone are enough, it seems to me, to place life and design in quite separate categories. Life’s complexity and its nested hierarchy of traits are also highly significant differences. The overall conclusion is clear: life looks undesigned.

Table 1. Similarities and Differences Between Life and Design
Similarities
DesignLife
Intermediate level of structural complexityIntermediate level of structural complexity
Modular structureModular structure
Evidence of careless modification (jury-rigging, vestigial parts)Evidence of careless modification (jury-rigging, vestigial parts)
Change over time; new forms are modifications of previous formsChange over time; new forms are modifications of previous forms
Functional integrationFunctional integration
Differences
Blueprints, tools, and other evidence of the design processNo evidence of design process
Simple organizationComplex organization; intermodular interdependence
ManufactureReproduction, growth, and development
Generally repaired from outsideSelf-healing, at least in part
Form follows functionForms follows nested hierarchy
Rapid changeSlow change
It bears repeating that the properties of design that I have considered are properties of human design, and they do not necessarily apply to a supernatural designer. However, human design is the only model of design we have by which to tell what design looks like, to the extent that design can be said to look like anything. If it does not look like this, it does not look designed.

The reader has probably realized by now that most of the aspects of life that look designed are also evidence of its evolution. In the cases of evidence of careless modification and change over time, the connection is explicit. An intermediate level of structural complexity probably arises from the selection and recombination inherent in evolution. Functional integration is not necessarily evidence for evolution but is an essential aspect of it. Modular structure is the only other aspect that design has in common with life that is not also evidence for evolution, but it is at least consistent with evolution. Even fine-tuning argues for life’s changing to fit the environment.

To the extent that life looks designed, life looks evolved. This should not come as a great surprise, because the process of design and the process of evolution share some important commonalities (see also Shanks and Joplin 2000). Both processes build upon what has gone before, and both processes select the "good" features and discard what does not work. There are also important differences, to be sure, but the similarities in process should not be overlooked.

Creationists have been criticized for their misrepresentations of biology and other sciences. Their representation of design is no less faulty. They consider complexity to be a hallmark of design, while simplicity is typically the designer’s aim. They believe that design and chance are mutually exclusive, whereas trial and error is sometimes used in design and, in the long run, is an inevitable and invaluable part of it. Finally, they treat design as an event, when in fact it is a process — a process that itself can be designed. Such misconceptions not only make for flawed theology, they cannot be good for engineering practices, either.

In fact, it would not be an exaggeration to say that "intelligent design theory" is not about design at all. Since most of the people who espouse it seem to view the design as a sudden all-at-once event, their model (not surprisingly) seems to be that of the fiat creation described in the Bible and Koran, not the extended process that familiar design entails. If creationists want to describe a different mechanism than design, they should use a different label for it. I suggest "decree", which has the advantage of fitting the theological position that underlies their ideas.

In both science and engineering, precise specifications are important. Two hundred years have passed since Paley popularized "intelligent design theory" (Paley 1802), and creationists have not yet satisfactorily clarified what they mean by "design", much less suggested useful tests for detecting it. At best, "intelligent design theory" is undefined and thus wholly useless. At worst, taking the phrase "looks designed" at face value as indicating analogy to human design, "intelligent design theory" is contradicted by the evidence.

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About the Author(s): 
Mark Isaak
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