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Jonathan Wells's book Icons of Evolution
and why most of what it teaches about evolution is wrong

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[Last Modified: January 23, 2004]

Contents

Also see the Icons of Evolution FAQs for more articles and links on this subject.

A chapter-by-chapter critique of Icons of Evolution:

Introduction

Jonathan Wells's book Icons of Evolution: Science or Myth? Why Much of What We Teach About Evolution Is Wrong (henceforth Icons) makes a travesty of the notion of honest scholarship. Purporting to document that "students and the public are being systematically misinformed about the evidence for evolution," (p. XII) via common textbook topics such as peppered moths, embryo similarities, and fossil hominids [2], Icons in fact contains a bevy of its own errors. This is not original -- creationists have been making mistakes about evolution for years. Newly and more insidiously, however, Icons contains numerous instances of unfair distortions of scientific opinion, generated by the pseudoscientific tactics of selective citation of scientists and evidence, quote-mining, and "argumentative sleight-of-hand," the last meaning Wells's tactic of padding his topical discussions with incessant, biased editorializing. Wells mixes these ingredients in with a few accurate (but always incomplete) bits of science and proceeds to string together, often in a logically arbitrary fashion, a narrative that is carefully crafted to make the semblance of an honest case for Wells's central defamatory accusation: that mainstream biologists are "dogmatic Darwinists that misrepresent the truth to keep themselves in power" (pp. 242-243).

This essay will show that it is Wells's book Icons that is shot through with misrepresentations.

The central pillar of Wells's case is this:

"Some biologists are aware of difficulties with a particular icon because it distorts the evidence in their own field. When they read the scientific literature in their specialty, they can see that the icon is misleading or downright false. But they may feel that this is just an isolated problem, especially when they are assured that Darwin's theory is supported by overwhelming evidence from other fields. If they believe in the fundamental correctness of Darwinian evolution, they may set aside their misgivings about the particular icon they know something about." (Icons, pp. 7-8)

In other words, Wells argues that the specialists know about the problems in their field of expertise, but that everyone thinks that the evidence supporting evolution is somewhere else. This is just plain false, as we shall see -- the experts in each field have explicitly stated that the evidence in their field supports evolutionary theory, and further they have supported their statements with evidentiary arguments. If Wells's contention about the experts is false, then Wells's argument collapses. Wells likes asking questions; it is now time for him to answer some.


Chapter 2: Miller-Urey experiment

Prebiotic Oxygen. A key question in origin-of-life research is the oxidation state of the prebiotic atmosphere (the current best guess is that the origin of life occurred somewhere around 4.0-3.7 bya (billion years ago)). Wells wants you to think that there is good evidence for significant amounts free oxygen in the prebiotic atmosphere (significant amounts of free oxygen make the atmosphere oxidizing and make Miller-Urey-type experiments fail). He spends several pages (14-19) on a pseudo-discussion of the oxygen issue, citing sources from the 1970's and writing that (p. 17) "the controversy has never been resolved", that "Evidence from early rocks has been inconclusive," and concluding that the current geological consensus -- that oxygen was merely a trace gas before approximately 2.5 bya and only began rising after this point -- was due to "Dogma [taking] the place of empirical evidence" (p. 18). None of this is true (see e.g. Copley, 2001).

Why does Wells leave out the converging independent lines of geological evidence pointing to an anoxic early (pre ~2.5 bya) atmosphere?

Was the prebiotic atmosphere reducing? Are the Miller-Urey experiments "irrelevant"? The famous Miller-Urey experiments used a strongly reducing atmosphere to produce amino acids. It is important to realize that the original experiment is famous not so much for the exact mixture used, but for the unexpected discovery that such a simple experiment could indeed produce crucial biological compounds; this discovery instigated a huge amount of related research that continues today.

Now, current geochemical opinion is that the prebiotic atmosphere was not so strongly reducing as the original Miller-Urey atmosphere, but opinion varies widely from moderately reducing to neutral. Completely neutral atmospheres would be bad for Miller-Urey-type experiments, but even a weakly reducing atmosphere will produce lower but significant amounts of amino acids. In the approximately two pages of text where Wells actually discusses the reducing atmosphere question (p. 20-22), Wells cites some more 1970's sources and then asserts that the irrelevance of the Miller-Urey experiment has become a "near-consensus among geochemists" (p. 21).

None of this is meant to convey the impression that no controversies exist (both Cohen (1995) and the Davis and McKay (1996) article cited by the above-quoted Kral et al. (1998) are about the various competing hypotheses about the origin of life). But textbooks generally mention some of these hypotheses (briefly of course, as there is only space for a page or two on this topic in an introductory textbook), and furthermore generally mention that the original atmosphere was likely more weakly reducing than the original Miller-Urey experiment hypothesized, but that many variations with mildly reducing conditions still produce satisfactory results. This is exactly what is written in the most popular college biology textbook, Campbell et al.'s (1999) Biology, for instance. In other words, the textbooks basically summarize what the recent literature is saying. The original Miller-Urey experiment, despite its limitations, is also repeatedly cited in modern scientific literature as a landmark experiment. So why does Wells have a problem with the textbooks following the literature? Wells wants textbooks to follow the experts, and it appears that they are.

The RNA world.Wells writes (p. 22) as if the RNA world is an alternative to failed Miller-Urey-style experimentation. He cites no source for this claim, because the claim is pure obfuscation.


Chapter 3: Darwin's Tree of Life

Wells mixes up several issues in this chapter. As we saw in the previous chapter, he will give several topics each a cursory and incomplete treatment, raising doubts about each subject and connecting them together whether they are logically connected or not.

The Cambrian Explosion. Here Wells is running down a path well-worn by his creationist and Intelligent Design colleagues. As a result there is already significant literature available on the "animal phyla appeared suddenly, and without precursors, and all equally far apart from each other"-sort of contention.

Molecular Phylogeny. Wells's second argument against the Tree of Life deals with the 'molecular clock' hypothesis -- namely that DNA or protein sequence divergence is regular enough to date ancient splits between lineages. This hypothesis is indeed being questioned by scientists, as the influence of things like natural selection may well alter the rate of sequence change (e.g. cone snail venoms are a fantastic example of rapid sequence divergence under selective pressure; see Espiritu et al., 2001). And if these changes occur often enough then getting accurate clock dates, particularly for distant events, will be very hard. This is an entirely different thing from determining molecular phylogenies, however, which is what Wells is actually trying to debunk. But unfortunately for Wells, there is considerable evidence that these phylogenies are reliable and in reasonably good accord with phylogenies generated from other data. On the general subject of accuracy in molecular phylogenies see Theobald 2002b and for recent work on phyla evolution and metazoan molecular phylogenies, which are quite certainly not in crisis, see recent articles in places Evolution and Development (e.g., Collins and Valentine, 2001; Peterson and Eernisse, 2001).

The Root of the Tree of Life. The 'Tree of Life' is the idea, most famously advocated by Darwin, that all known life is descended from a common ancestor and is connected by a phylogenetic 'tree':

"The affinities of all the beings of the same class have sometimes been represented by a great tree. I believe this simile largely speaks the truth. The green and budding twigs may represent existing species; and those produced during each former year may represent the long succession of extinct species. ... As buds give rise by growth to fresh buds, and these, if vigorous, branch out and overtop on all sides many a feebler branch, so by generation I believe it has been with the great Tree of Life, which fills with its dead and broken branches the crust of the earth, and covers the surface with its ever branching and beautiful ramifications." (Darwin, Origin of Species)

This idea has recently been implemented on the web in a splendid fashion. See the Tree of Life Web Project Home Page.

In Icons, Wells has a ball with recent scientific debates over whether or not lateral gene transfer mixed up ancient genomes so much that deepest branches of the tree are mixed up. Basically, some scientists have proposed that the idea of a single "last common ancestor" should be replaced with the idea of a "last common gene pool" that the extant three domains of of life -- eukaryotes, archaea and eubacteria, in one classification scheme -- gradually emerged from. Carl Zimmer (2001) describes this as the 'Mangrove of Life' idea. Wells (of course) milks this for all it's worth, proclaiming the downfall of common descent and the 'uprooting of the tree' and whatnot, but he is distorting things.

The Chinese paleontologist story. On the last page of this chapter of Icons (p. 58), Wells recounts his story of an unnamed Chinese paleontologist who visited the U.S. in 1999 and who Wells quotes as saying, "In China we can criticize Darwin, but not the government; in America, you can criticize the government, but not Darwin." Given past experience with antievolutionist anecdotes, it is to be strongly suspected that there is more to this story than Wells is telling us.


Chapter 4: Homology in Vertebrate Limbs

Is the definition of homology circular? Wells spends this entire chapter thoroughly confused about homology, and does his best to confuse his readers as well. About five minutes of research by yours truly turned up a perfectly reasonable discussion of homology (Amundson, 2001) which nicely straightens things out: in a nutshell, homology is detailed similarity of organization that is functionally unnecessary, meaning the similarity is unnecessary (the trait in question may be, and usually is, functional).

This is not a drastically complicated idea, but Wells is able to confuse himself because post-Darwin, homology is usually defined as 'A feature in two or more taxa is homologous when it is derived from the same (or a corresponding) feature of their common ancestor.' Wells accuses scientists of making the definition circular and assuming common descent rather than providing evidence for it, but of course if you doubt common descent then you have to go back to the original definition, wherein you have peculiar similarities that are functionally unnecessary staring you in the face, begging you for an explanation. Amundson (2001) critiques the circularity charge well:

This criticism relies on a faulty view of what scientific definition amounts to. A scientific definition is not a semantic stipulation that creates an analytically true statement (i.e. a statement the denial of which is self-contradictory). Rather, a scientific definition typically states a property that is considered to be the most deeply explanatory of the phenomena that are central to the term being defined. Lankester and Mayr consider ancestry to explain patterns of homology, and stress that fact by making it the definition. The historical definition is not viciously circular as long as homologies can be recognized and picked out by criteria other than common ancestry. It is an empirical fact that homologies (as picked out by the criteria below) are arranged among organisms in a pattern that is explainable by common ancestry, and independent evidence from various fields supports common ancestry as a historical fact.

Complexities of Homology; R. A. Raff comments. On pp. 72-78, Icons cites Rudolf Raff and other scientists in an attempt to build a case that the use of homology is somehow in crisis. The reality of most of these cases is that scientists are simply discovering that different kinds of homology are found at different phylogenetic and organizational levels. Over the last few years, the growing synthesis of evolutionary biology and developmental biology has created a hot new subfield referred to as "evo-devo." For an introduction to evo-devo, see the article "The evolution of evo-devo biology," which heads up a an entire special issue on the topic that was published freely on the web by the journal Proceedings of the National Academy of Sciences (PNAS).

The evo-devo specialist Rudolph Raff recently (Nov.-Dec. 2001) wrote an editorial in the journal Evolution and Development entitled "The creationist abuse of evo-devo," specifically on Wells and his book Icons. Raff writes, in part,

Icons of Evolution presents the dark view of evolutionary biologists held by Wells. He says that we are involved in a conspiracy to consciously lie in what we teach students and present in our writings. Claims of deliberate scientific fraud and "Darwinian censorship" reaches a crescendo as the book progresses. These are strong accusations built on a shaky scaffolding of special pleading and deceptive use of quotations. [...] Wells notes correctly that there is not a necessary connection between homologous genes and homologous structures, nor must homologous structures arise from similar developmental processes. [Wells and colleagues conclude that...] "naturalistic mechanisms proposed to explain homology do not fit the evidence." What logical gymnastics! If it is unexplained, it must be unexplainable by evolutionary biology. If it's be unexplainable by evolutionary biology, it must require an intelligent designer. Unfortunately, as the influence of the intelligent designer grows in this train of thought, the relationships between phenomena and explanations becomes increasingly arbitrary. Finally one reaches a point where all biological features are "special creations" and other explanations become unnecessary. (Raff, 2001)

For a very detailed introduction to dozens of detailed homologies (none mentioned by Wells except the vague 'similarity' idea) within the chordates that have been discovered via comparative biology, see this webpage on Chordate Anatomy and Evolution ( http://www.auburn.edu/academic/classes/zy/0301/comparative_home/comparative_home.html).


Chapter 5: Haeckel's Embryos

In the interests of forthrightness, one point must be conceded straight out: Haeckel's embryo drawings have no place in textbooks except as an example of how erroneous ideas can get tacked onto important truths and perpetuated even after being debunked (Haeckel's inaccurate drawings have actually been 'exposed' multiple times since the 1800's, the Richardson et al. (1997) article that Wells cites being only the most recent example). However, Wells as usual exaggerates the implications of this for evolution.


Chapter 6: Archaeopteryx: The Missing Link

Archaeopteryx has long been something that creationists have felt the need to deal with somehow, as it is a clear fossil intermediate between two vertebrate classes. However, creationist claims have been refuted so often and so thoroughly regarding Archaeopteryx that very little remains for Wells to do except raise a smoke screen over whether or not Archaeopteryx was the actual species through which the genes of the last common ancestor of modern birds passed, or whether it was a closely related side-branch. Either way, it is clear evidence that a transition between the classes occurred.


Chapter 7: Peppered Moths

So many things are wrong with Wells's treatment of peppered moths (Biston betularia) that it is hard to list them all; but I will try. The authoritative reference on this topic is Michael Majerus' 1998 book Melanism: Evolution in Action. This book includes two long chapters on Biston. The first chapter, "The peppered moth story," recounts the basic story of melanism in Biston, and relates how this story was pieced together by Kettlewell and others. The second chapter, "The peppered moth story dissected," gives a thorough critical review of the basic story, considering aspects and details of the basic story in the light of research (by Majerus and others) post-dating Kettlewell.

Crucially, however, Majerus clearly and explicitly concludes that, in his view, Kettlewell got things basically correct. At the beginning of his second peppered moth chapter, Majerus writes,

First, it is important to emphasize that, in my view, the huge wealth of additional data obtained since Kettlewell's initial predation papers (Kettlewell 1955a, 1956) does not undermine the basic qualitative deductions from that work. Differential bird predation of the typica and carbonaria forms, in habitats affected by industrial pollution to different degrees, is the primary influence of the evolution of melanism in the peppered moth (Majerus, 1998, p. 116).

Majerus is so clear on this point that one suspects that he was anticipating that his critique would be misinterpreted by non-peppered moth researchers. It seems that there is a "too good to be true" quality about the peppered moth story that leads people to interpret any hint of criticism as a sign that the whole basic story is crashing down. Scientists are by no means immune to this tendency, and indeed they may be more prone to it given the regularity with which popular ideas have been overturned throughout the history of science. The press has an even greater tendency towards snap judgements and oversimplifications when it comes to scientific discussions. Antievolutionists, on the other hand, have always been stuck muttering "it's just microevolution within a species." While this is true, the rapidity and obvious adaptiveness of the change effected by natural selection still seemed to give antievolutionists discomfort. Therefore, it is understandable that when Wells and his fans sniffed a scientific controversy over peppered moths (in truth it was a fairly marginal kind of controversy), they blew things way out of proportion.

Summary of Wells's treatment of moth resting places. To review, Wells's primary objection to the peppered moth story was this:

Most introductory textbooks now illustrate this classical story of natural selection with photographs of the two varieties of peppered moth resting on light- and dark-colored tree trunks. (Figure 7-1) What the textbooks don't explain, however, is that biologists have known since the 1980's that the classical story has some serious flaws. The most serious is that peppered moths in the wild don't even rest on tree trunks. The textbook photographs, it turns out, have been staged. (Icons, p. 138)

[Figure 7-1 is on Icons, p. 139; these are drawings by Icons illustrator Jody F. Sjogren; the source photo, if there is one, is not cited. Confusingly, the caption for the figure is not on page 139 but overleaf on page 140. These are not encouraging signs in a book purporting to critique textbooks.]

The discussion thus far has shown that Wells's "most serious objection" to the peppered moth story is completely baseless: first, peppered moths do in fact rest on tree trunks (a significant portion of the time although not the majority of the time, according to Majerus' data). Second, textbook photos are used to show relative crypsis of moth morphs, not to prove that peppered moths always rest in one section of the trees. And third, Majerus himself has taken unstaged photos of peppered moths on matching tree trunk backgrounds, and these are not significantly different than staged photos; this eviscerates whatever vestige of a point Wells thinks that he has.

The scientific literature. Having dealt with Wells's "most serious objection," let us turn to Wells's use of the scientific literature. The primary problem is that Wells gives inordinate weight to a few scattered review papers, by biologists who are not major peppered moth researchers [4], that question the standard view (that bird predation on different colored moths on differently polluted backgrounds caused the darkening of moth populations as pollution increased, and that as pollution decreased this process worked in the opposite direction). Their criticisms have been answered by peppered moth researchers (Grant, 1999; Cook, 2000; Grant and Clarke, 2000; Majerus, 2000). And, as pointed out in the introduction, since Wells bases his argument on the idea that the experts are disowning the 'icons' in their respective fields, Wells is falsified if those experts contradict him.


Chapter 8: Darwin's Finches

"Darwin's Finches" are a group of closely-related bird species located on the Galápagos islands. The finches have been studied ever since Darwin made the first collection of these species, but the best-known recent work has been conducted by the husband-and-wife team of Peter and Rosemary Grant and their collegues and students. See Peter Grant's 1986 book Ecology and Evolution of Darwin's Finches and subsequent articles by the Grants, and especially Jonathan Weiner's 1994 book The Beak of the Finch: A Story of Evolution in Our Time for a popular introduction to their work. See also the March-April 2002 issue of American Scientist, "Adaptive Radiation of Darwin's Finches," by Peter and Rosemary Grant. The abstract and some graphics are online here: http://www.americanscientist.org/articles/02articles/Grant.html.

Finches not relevant to Darwin? Wells claims that the finches were not relevant to Darwin's development of evolutionary theory, but Wells is playing fast and loose with the facts here. Wells writes (p. 160) that the finches "are not discussed in [Darwin's] diary of the Beagle voyage except for one passing reference." Wells (p. 162) does include a quote from the two pages that Darwin spent on the finches in The Voyage of the Beagle (Wells, like Weiner, calls it Journal of Researches), but neglects the well-known fact that this quote constitutes the first publicly published hint of evolutionary theory from Darwin (Weiner, 1994). Wells also leaves out mention of the prominent figure that Darwin put in Voyage of the Beagle, showing the differently-adapted beaks of the finches. You can read the quote yourself on page 405 of the British Library's online edition of Voyage of the Beagle. The various legends that have grown up around Darwin and the finches -- similar to Galileo and the Leaning Tower of Piza -- are well addressed in Jonathan Weiner's The Beak of the Finch (pp. 35-36), minus the patronizing editorializing of Wells. Darwin made the first scientific collection of the finches, so the label "Darwin's Finches" is entirely appropriate.


Chapter 9: Four-Winged Fruit Flies

Wells must have been hard up for icons at this point, considering that in the text he cites (p. 185) exactly one textbook that uses the example, and mysteriously leaves this "Icon" out of his textbook evaluation (p. 249). Wells leaves fossil horses and fossil hominids out of this evaluation, also, although for different reasons as they are ubiquitously cited in textbooks.


Chapter 10: Fossil Horses and Directed Evolution

It is evident from the chapter title that Wells can find no particular beef with fossil horses; not only do they not make the list of criteria for textbook evaluation, they don't even make Wells's list of "10 questions to ask your biology teacher" (at: http://www.iconsofevolution.com/tools/questions.php3). There is an obvious question ("Aren't fossil horses pretty darn good evidence for microevolution adding up to macroevolution"), but it seems unlikely that it will be added to the list. For a detailed introduction to fossil horses see Hunt (1995).


Chapter 11: From Ape to Human: The Ultimate Icon

At long last, we come to The Ultimate Icon, the one on the cover of Icons of Evolution: the March From Ape to Man. However, at this point Wells seems to have completely lost track of textbooks, which you may recall were supposed to be the topic of the book (this Icon does not appear in Wells's evaluation criteria on page 249, either). The only mentions of textbooks in this chapter are listed below:


Conclusion -- Jonathan Wells's book: Science or Myth?

This concludes the tour of Jonathan Wells's Icons of Evolution. At the end of Icons, Wells includes an Appendix where he "grades" ten recent biology textbooks, giving most of them an F (Campbell et al.'s Biology -- probably the most popular college biology text, by the way -- comes out on top with a D+). Wells then includes "warning labels", which look suspiciously like cigarette warning labels, which Wells thinks should be put in textbooks.

Has Wells succeeded in making the case which would justify his harsh judgements? Let us recall what Wells's argument was supposed to be:

"Some biologists are aware of difficulties with a particular icon because it distorts the evidence in their own field. When they read the scientific literature in their specialty, they can see that the icon is misleading or downright false. But they may feel that this is just an isolated problem, especially when they are assured that Darwin's theory is supported by overwhelming evidence from other fields. If they believe in the fundamental correctness of Darwinian evolution, they may set aside their misgivings about the particular icon they know something about." (Icons, pp. 7-8)

But as we have seen, in every single case, the actual biological experts in their specific fields of expertise in fact agree that the actual evidence in their field supports modern evolutionary theory. Furthermore, many of these scientists have felt sufficiently strongly about this that they have published critiques of creationist misinterpretations of their work. Many of these scientists have felt sufficiently victimized by Wells to write specific rebuttals of him.

Wells might try to argue that he was talking about the "icons" rather than the general evidence in the field, but still his argument fails. In the cases of the Miller-Urey experiment, Darwin's tree of life, vertebrate limb homology, Archaeopteryx, peppered moths, and Darwin's finches, a fair investigation of the literature has revealed that Wells has no case, and that these "Icons" are fully deserving of inclusion in biology textbooks. In the cases of the four-winged fruit fly, fossil horses, and fossil hominids, we discover that Wells has not even included these cases in his textbook "evaluation" criteria -- perhaps inclusion of these in the criteria would have raised the textbook grades too much. In any case it is evident that Wells's problems with the four-winged fruit fly, fossil horses, and fossil hominids are not really with textbooks, but with extraneous issues -- the real issues in these cases are Wells's bizarre views about the relationship between genes and development, and his paranoia that biology textbooks are pushing the view that life is meaningless and purposeless. I will have a few final words on this subject in a moment, as it is an oft-recurring theme in antievolutionist writings.

The single "icon" where Wells has some success is with Haeckel's embryos: the fraction of textbooks that use Haeckel's drawings should replace them with photographs or more accurate drawings. But even here, the very authority that Wells cites against Haeckel's embryos, namely M.K. Richardson, has clearly stated that the actual. facts of embryology do indeed support evolutionary theory, contradicting Wells's interpretation. As Wells's argument is explicitly based on the views of the experts in their fields, then Wells, to be self-consistent, would have to concede that he has only scored a point against certain textbooks, and not against the theory of evolution.

However, let us be generous and grant Wells a full point for the Haeckel's embryos case. On the other nine "icons," though, Wells has come up empty-handed. So Wells has earned a 1 out of 10. Even a generous curve would not save Wells from a flunking grade. One would think that a guy with a Ph.D. from Berkeley would have done better.

The only thing more discouraging than Wells's grade are the rave reviews that Wells got from his peers at his current workplace, the Discovery Institute. Wells' fellows at the Discovery Institute's Center for the Renewal of Science and Culture lavished praise on Icons of Evolution, with nary a word of criticism or even mild questioning. Sure, we might expect antievolutionist demagogues to do their usual braying; for example, in his typically balanced style Phil Johnson writes of Icons, "This is one of the most important books ever written about the evolution controversy. It shows how devotion to the ideology of Darwinism has led to textbooks which are full of misinformation." But even Michael Behe, who does know some biology and really should have known better, has apparently become radicalized enough to write, "Jonathan Wells demonstrates with stunning clarity that the textbook examples Darwinists themselves chose as the pillars of their theory are all false or misleading. What does this imply about their scientific standards? Why should anyone now believe any of their other examples?" This is the same Behe, you will recall, who accepted the evidence for common descent -- i.e. the tree of life -- as recently as 1996. What is the intellectual status of a movement like Intelligent Design that cannot bring itself to question even the most outrageous of Jonathan Wells's distortions? (for the above reviews and others, see this URL: http://www.iconsofevolution.net/reviews/)

I have only had time to refute the major arguments that Wells raises in Icons; unfortunately this only scratches the surface. A truly thorough refutation would take a full book, and one rather longer than Icons at that. I fear that I have not given readers a sufficient impression of just how deceptive and devious a writer Jonathan Wells is. Through most of the book, virtually every sentence contains some sort of illegitimate slant, whether quoting a scientist out of context, or leaving out crucial pieces of information, or presenting a nonexpert opinion as an authoritative one, or simply spewing out unsupported exclamations of doubt, derision, and "dogmatic Darwinism!" Icons is an impressive bit of propaganda, and frankly, Jonathan Wells is probably the slickest operator that the antievolution movement has ever produced. His book, packed with quotes and authoritative declarations, mangling topic after topic in rapid succession, is a calculated attempt to overwhelm the reader by sheer diversity of material; even the biologically educated reader is not likely to have the necessary background to spot all of Wells's tricks. Writing this review required a substantial amount of research and help from numerous veteran creationism/ID debaters (see Acknowledgements).

But Wells's cleverest move of all was to attack textbooks rather than taking on the science directly. The all too common response, even from biologists, has been along the lines of "Well, sure, textbooks have problems, but this doesn't affect the theory of evolution." This is falling into Wells's trap. This review has shown that the topics discussed actually do belong in textbooks, and do constitute good evidence for evolution, according to the evidence and according to the experts that Wells claims for support. The book Icons of Evolution is the real scientific travesty.

What is Icons really about?

The central irony of Icons of Evolution is that, while biologists no longer accept and indeed actively debunk the "March From Ape-to-Man" image on the cover, it appears to be closer to something that Wells believes. He apparently does not deny common ancestry of humans with animals; on page 223 (in the middle of six pages of selective quoting about the subjectivity and disagreements in paleontology) Wells admits, "Obviously, the human species has a history. Many fossils have been found that appear to be genuine, and many of them have some features that are ape-like and some that are human-like." It seems like Wells's next sentence ought to be "Sorry for all the trouble, folks, I guess I got a little carried away with this book...", but of course it isn't. As far as anyone can tell, Wells has the idea that "the human species was planned before life began, and that the history of life is the record of how this plan was implemented" (see his essay "Evolution and Design," online here: http://www.tparents.org/Library/Unification/Talks/Wells/0-Toc.htm). In other words, to Wells, evolution (with some unspecified touch of ID) was marching towards a goal of humans, just like the Apes-to-Man icon on the cover of Icons of Evolution! It seems likely that the insertion of this metaphysical idea into science education, as science, is Wells's real goal.

But is it really necessary to force theology into science? As we saw in the fossil horses chapter, Wells imputes far more metaphysical significance to words such as "random" and "undirected" than they actually have scientifically. Scientifically, evolution is described as "random" and "undirected" in the same way that the weather, earthquakes, and numerous other natural processes are described as "random" and "undirected." (For that matter, evolution is also predictable in a way similar to weather and earthquakes.) Does describing the weather, or evolution, as somewhat "random" really have the offensive metaphysical implications that Wells thinks?

For an alternative model, we should investigate the central quote of Wells's last chapter. Wells is severely offended by Dobzhansky's statement "Nothing in biology makes sense except in the light of evolution" and decries all of the evil materialist-naturalist metaphysics he sees in it. But Wells, as usual, fails to give his reader crucial information: Wells fails to say anything about Dobzhansky's actual metaphysics: Dobzhansky was a life-long Russian orthodox Christian. Here are some more quotes from the very same article by Dobzhansky (1973), which is available online at http://www.2think.org/dobzhansky.shtml.

"It is wrong to hold creation and evolution as mutual exclusive alternatives. I am a creationist and an evolutionist. Evolution is God's, or Nature's, method of creation. Creation is not an event that happened in 4004 B.C.; it is a process that began some 10 billion years ago and is still under way."

"Does the evolutionary doctrine clash with religious faith? It does not. It is a blunder to mistake the Holy Scriptures for elementary textbooks of astronomy, geology, biology, and anthropology. Only if symbols are construed to mean what they are not intended to mean can there arise imaginary, insoluble conflicts. As pointed out above, the blunder leads to blasphemy; the Creator is accused of systematic deceitfulness."

(Dobzhansky T., 1973, "Nothing in biology makes sense except in the light of evolution", American Biology Teacher 35:125-9)


Acknowledgements

This article was composed with valuable help and comments from Bruce Grant, Bob Hagen, Wesley Elsberry, Michael Hopkins, Burt Humburg, Ian Musgrave, Pete Dunkelberg, Jesse, igkappa, theyeti, and several others.

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References

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Notes on the revised version

In the year and a half since this FAQ came out, numerous additions to the anti-Icons literature have become available. Most important among these is Alan Gishlick's detailed review for NCSE, with excellent figures and tables illustrating what textbooks actually say, versus Wells's characterization of them. On the other hand, the present FAQ focuses specifically on debunking Wells's argument that experts believe that each "icon is misleading or downright false". Wells is still making this argument. For example, in his short non-response to Gishlick, Wells wrote,

Unfortunately for Gishlick, the cats are already out of the bag. When I lectured to biology students on a state university campus recently, their professors were incredulous when I told them that some people still defend the Miller-Urey experiment, Haeckel's embryo drawings and the peppered myth. The NCSE's desperate attempts to defend the indefensible are not fooling biologists in the field. (Wells, December 13, 2002)

Of course in his little story Wells doesn't name the university in question, so this part remains uncheckable. But the bit about "biologists in the field" certainly is checkable, and Wells is dead wrong. Even for Wells's favorite two topics, embryos and peppered moths, Wells's originally-cited authors continue to oppose the creationist spin. Wells's primary sources for his claims about embryos and moths were Richardson et al. (1997) and Majerus (1998), respectively. But, in addition to their comments quoted in the first version of this FAQ, in 2002 each of these authors published more work undermining Wells. Richardon co-wrote an article (Richardson & Kueck 2002) indicating that even I was a bit too hard on Haeckel's embryos, saying that "Haeckel's much-criticized embryo drawings are important as phylogenetic hypotheses, teaching aids, and evidence for evolution." And Majerus published his book Moths, including a several page refutation of those who have misinterpreted his work as discrediting Kettlewell's natural-selection-by-bird-predation hypothesis for peppered moth color change. Majerus, citing the support of all his fellow peppered moth researchers, wrote, "I believe that, without exception, it is our view that the case of melanism in the Peppered moth still stands as one of the best examples of evolution, by natural selection, in action" (Majerus 2002, p. 252). Strangely, Wells thinks he can cite "biologists in the field" for support even when what they say directly contradicts Wells's arguments.

As the first version of this FAQ was already fairly long and comprehensive, not much new material has been added in the revision, except that each section now includes a box with links to the most important articles on each topic. In several cases, graphics have been improved. To improve readability, Wells's quotes have been put in green boxes, and the quotes of mainstream writers have been put in orange boxes. The spelling of the possessive form of "Wells" has been changed from "Wells'" to "Wells's." This is the correct usage according to the The Apostrophe Protection Society. However, proper nouns with three or more syllables evidently only get one "s," so "Majerus'" remains unchanged.

Endnotes

[1] Nicholas Matzke, formerly known by the pen name "Nic Tamzek."
http://www.geog.ucsb.edu/~matzke/

[2] The introduction to the book, containing the list of Wells's "icons", can be found online here: http://www.iconsofevolution.org/intro/

[3] Because "Archaeoraptor" was never formally described in a scientific journal, it is not a valid scientific name and therefore should not be italicized.

[4] It might be objected here that Sargent (of the paper Sargent, Millar, and Lambert, 1998, "The "classical" explanation of industrial melanism: assessing the evidence," in Evolutionary Biology, 30:299-322), is a moth researcher. This is true, but most of Sargent's work appears to be on moth species other than peppered moths, such as the genus Catocala. In genera such as Catocala the situation regarding industrial melanism and selection appears to be different. Majerus barely cites Sargent at all in his detailed review of peppered moths in Melanism: Evolution in Action.

Regarding the Sargent et al. paper, which is the major source for those proclaiming the downfall of the classical peppered moth story, an under-realized fact is that it is formally a review of industrial melanism in moths in general, and in many species other than the peppered moth (Biston betularia) the evidence is indeed poor that the "classical explanation" (selective predation against backgrounds changing due to pollution) applies. Peppered moths of course come up repeatedly as they are the species on which the most work has been done, and the authors do question the classical explanation for peppered moths as well. However, the peppered moth experts are unimpressed, just as they were unimpressed by a 1986 paper by some of the same authors (Lambert, Millar, and Hughes (1986), "On the classic case of natural selection", Rivista di Biologia, 79:11-49.). Here is Cook's (2000) take:

Work by H. B. D. Kettlewell suggested that selective predation was the main determining factor in B. betularia, and probably in a wide range of other examples as well. His evidence consisted of surveys which put the correlation between melanic frequencies and urbanization on a quantitative basis (Kettlewell, 1958, 1965), demonstration that wild birds would eat the moths if they found them (Kettlewell, 1955), and the now famous demonstration that birds discovered most readily the forms least like the daytime backgrounds on which they rested (Kettlewell, 1973; Rudge, 1999). Colour of resting background and heterogeneity due to epiphyte cover, appeared to affect relative visibility. Selective predation became the accepted explanation for the rise in morph frequency (Majerus, 1998).

Since then, further evidence has been collected. Over the last two decades industrial environments have become cleaner and melanic frequencies lower (Clarke et al., 1990; Mani & Majerus, 1993; Grant et al., 1998; Cook et al., 1999). There has also been some revision of interpretation. It has been shown that experiments designed to detect and measure selective predation were carried out in places where moths were not usually likely to rest if left to their own devices (Mikkola, 1979, 1984; Liebert & Brakefield, 1987; Grant & Howlett, 1988; Majerus, 1998). There is by no means a one-to-one relation between reversion of morph frequency and reversion of epiphyte pattern (Bates et al., 1990; Grant et al., 1998). These findings cause us to reexamine the story, but they do not obviously require a radical revision. Estimations of selection appear to show a correspondence between fitness and frequency. The correlation between the condition of the sites used in experimental studies and those actually used by the insects is likely to be high. Further lines of experimentation are suggested, but no previously held view has been overturned.

The general tone of commentary on Biston studies has, however, altered. From being treated as a vivid demonstration of natural selection (Luria, Gould & Singer, 1981, provide an excellent example) and good field experimentation (Hagen, 1999), the work concerned has come to be viewed with suspicion (Sermonti & Catastini, 1984; Cherfas, 1987). In a recent review by Sargent et al. (1998) almost every reference to past work is predicated by expressions of doubt, reworking ground covered by Lambert et al. (1986). When discussing predation experiments they conclude ". . . there seems to be no clear and consistent relationship between the relative survivorship of different morphs . . . and the frequencies at which the morphs naturally occur in different environments". Coyne (1998) adopts a similar tone, saying that the flaws in the work are too numerous to list. This has led to some alarming reporting, such as Matthews (1999) in the Daily Telegraph newspaper in Britain, who refers to a "series of scientific blunders" and states that the experiments are "now thought to be worthless". This article in turn was linked in its electronic web version to the Creation Science home page. Recent commentaries are quoted on more than one anti-evolution web site. A balanced account, which shows the strength of the data in the face of recent criticism, has been provided by Grant (1999). I propose here to illustrate the predation results, which Sargent et al. did not do when they criticized them, and to consider why a radical change in view should have occurred.

Cook's conclusion about the state of the evidence and the somewhat baffling criticism the peppered moth story has received:

CONCLUSION

In industrial melanism of Biston betularia, both the original increase and recent decline in frequency of melanics are striking examples of natural genetic change closely related to change in the environment. They must have a selective basis. The experiments demonstrate selective removal. There is a general correspondence of morph frequency and appearance of backgrounds likely to be adult resting sites. None of this is in doubt. The evidence is, however, limited in two ways. First, non-visual components of selection have not been investigated directly in this species. Analysis of segregating progenies suggests pre-adult survival differences (Creed et al., 1980) with carbonaria homozygotes having an advantage over other morphs. Non-visual selection is certainly indicated in studies of other melanic moths (Bishop & Cook, 1980), but we have little more idea than Leigh (1911) how it may operate.

Secondly, the experimental and observational evidence cannot on its own carry the burden of a particular view of evolution, such as found in Oxford ecological genetics. Smocovitis (1996) describes how the view of the [Neodarwinian Modern] Synthesis with which it was associated came to seem 'constricted' to many students of evolution, and to generate a reaction in favour of more complex models; the last three decades have been a period of lively debate and controversy. Distrust of the evidence of industrial melanism may sometimes arise from a wish to question how the example relates to more complex levels of evolutionary theory. Criticism on these grounds is misplaced, and can attract the attention of advocates of creationism who see an evolutionary field in apparent disarray. The Biston story continues to provide an exceptional opportunity to analyse a pattern of selection. It should be pursued, along with study of other species with related but different responses to environmental change.

It should also be pointed out that while Sargent appears skeptical of some of the evidence for the classical peppered moth story, he has no problem with the general idea of cryptic (camouflage) coloration in moths; he writes that the classical explanation is "eminently reasonable", and furthermore he has himself published on crypsis in moths. A very interesting webpage on Sargent's observation of the behavior of another moth species, Catocala relicta, is online here: http://bcrc.bio.umass.edu/kunkel/Moths/relicta_story.html. Notably, the evidence is against this kind of "find a matching background" behavior in peppered moths. Peppered moths appear to just look for shaded spots (such as beneath trunk-branch joints), whether or not the moth is dark or light colored. As Sargent et al. grudgingly acknowledge, this is actually a good thing for the classic selection-by-bird predation story for peppered moths, as picking-matching-background behavior would actually constitute negative feedback that would weaken the effects of natural selection (i.e., as tree surfaces got darker, the moths would just behaviorally move to lighter surfaces that matched their camouflage).

Regarding Jerry Coyne's (1998) review of Majerus' book Melanism: Evolution in Action in Nature ( online here), readers should not allow Coyne's excellent reputation as a nonsense debunker to dissuade them from recognizing that Coyne's review contains at least one glaring mistake: namely, Coyne writes, "Majerus notes that the most serious problem is that B. betularia probably does not rest on tree trunks -- exactly two moths have been seen in such a position in more than 40 years of intensive search. The natural resting spots are, in fact, a mystery." However, Coyne somehow fails to mention that in the very next paragraph of Majerus' book (pp. 121-122), Majerus cites his own data on the natural resting places of moths -- some 47 moths -- not a lot, but far more than two. This data, listed in Table 6.1 of Majerus' page 123, indicates that peppered moths in fact rest in diverse locations (12 on tree trunks, 20 on "trunk-branch joints", and 15 in tree branches). Similar percentages are found in Table 6.2 on a larger dataset of resting moths found near traps.

All of this serves to illustrate that Coyne's opinion on the classical peppered moth explanation is by no means definitive. Wells, of course, gives readers very little of the above complexity of the true situation, and instead quotes the juicy bits of Coyne's review. Wells's own treatment of moth resting locations appears to be deliberately deceptive. Wells refers to Clarke et al.'s (1985) reference to the two moths collected (Clarke was basis for Coyne's remark also), and goes on to selectively quote two additional papers on the topic of resting locations, as well as Majerus' book, to support the notion that moths don't rest on tree trunks. In the notes (p. 304) Wells buries a reference to Majerus' book amongst the other papers, and refers readers only to page 116 of Majerus' book, when in fact the section "The resting behaviour of peppered moths", including the tables, is found on pp. 121-123. Why does Wells not just put the numbers, which are the best anyone has, in the text for his audience to read?

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