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Created 22 December, 2000;
last updated: 8 February, 2002
A review of
"ICONS OF EVOLUTION - Science or Myth? Why Much of What We Teach About Evolution is Wrong", by Jonathan Wells, (Regnery Publishing, Washington, D.C., 2000).
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The purpose of Icons of Evolution, Jonathan Wells claims, is to encourage people to ask questions about evolution, and to document that "students and the public are being systematically misinformed about the evidence for evolution". He claims to be objectively looking at the issue, and from reading the preface, one gets the feeling that Wells just stumbled onto his discovery that the textbooks were trying to trick poor unsuspecting students into believing in Darwinian evolution. After reading the book, I am convinced that Wells does a quite good job of summarising some of the Creationist's criticisms of evolution, but he fails miserably in his task of documenting his claim of fraud and conspiracy amongst scientists to purposefully and systematically misinform the public. I shall try in this review to explain why I am not convinced by his arguments, and why I feel that this book is nothing more than yet another attempt for the Creationists to try and sneak their agenda into the public schools, under the guise of science.
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"Those who wish to succeed must ask the right preliminary questions."
-Aristotle
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People ask questions all the time, and in fact I often use questions to try to encourage students to think for themselves, rather than telling them they are about to do (or have done) something dangerous or wrong. For example, I recently discovered that a person was about to pour buffer into an electrophoresis box, sitting on top of a 2000 V power supply. "Will the buffer conduct electricity?", I asked. "Yes", was the reply. Then I continued - "Now let's think about this for a minute. What would happen if you were to spill some of the buffer, and it were to flow into the power supply sitting underneath the gel box? Do you think this is a good place to put the gel box?" The answer was obvious - there could be an electrical short, or perhaps even an explosion. The gel box was moved to a different location. The point I want to make is that there are different types of questions, and some are more likely to yield fruitful answers than others. When doing an experiment, it is very important to sit down and plan out what is the goal - that is, one must ask the right questions, so to speak, if they want a clear answer.
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Wells has a set of questions he would like students to ask their teachers of evolution. I think there are good answers to his questions, and of course the teachers should be prepared to answer them, although the answers I have in mind are probably a bit different than what Wells anticipates.
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I readily agree with the idea that the textbooks used in public schools often contain poor coverage of science topics. In a limited sense, I can understand Wells' criticism of the coverage of biology in textbooks. I think the problem is not only just biology, though - and furthermore, I don't think that eliminating "evolution" from the books will solve the larger issue of lack of responsible editing of the textbooks. A recent review of science text books commonly used in Middle schools found that many textbooks were "deplorable". This review was done by physics instructors, and they were mainly looking at factual errors, such as labelling figures incorrectly, confusing "force" with "acceleration", or simply explaining things that obviously could not be true. However, I was a bit surprised to read that virtually ALL of the biology textbooks got a failing grade, according to Wells. I would invite the interested reader to compare the reviews of textbooks in The Textbook Letter with the reviews given in the appendix of "Icons of Evolution". For example, The Textbook Letter rates Niel Campbell's BIOLOGY very high - "This Impressive Textbook Is Strongly Recommended" is the title for their review. Having used the textbook myself in teaching undergraduate biology, I tend to agree with this - it is one of the best biology textbooks I've seen. However, Wells gives it a grade of "D+", which incidently is the highest grade of the 10 textbooks he's reviewed. Why does even the very best textbook fail? Because it presents [some of] the "false icons" of evolution.
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I actually have no problem at all with the idea presented by Jonathan Wells that one should be free to ask questions about evolution. From my perspective, as a molecular biologist working with an interdisciplinary bioinformatics group of physicists, computer programmers, medical doctors, and chemists, I know what it is like to try and explain results to other scientists outside one's discipline, and I am more than willing to accept the premise that there are some commonly used examples of evolution which are more complicated in real life than is often portrayed. However, contrary to what is claimed in the introduction, this book is not about simply asking "hard questions" to scientists - it is part of a systematic attempt to discredit evolution in order to replace it with an alternative (namely belief in special Creation by a Divine Intelligent Designer Something - but of course Wells implies that this is a scientific explanation, and has nothing to do with Creationism). What kind of evidence can I present to build my case? Perhaps it is merely a coincidence that Wells' claims are essentially the same as the Creationists, or alternatively, maybe he really does have a valid point here - what's wrong with asking questions?
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Suppose that someone really did not like statistical mechanics, since it clearly assumes an element of randomness in the world around us, and that this person's religious belief was in a Creator who would not allow such randomness. Now it is possible to derive the ideal gas law (PV=nRT, where P=Pressure, V=Volume, n=number of molecules, R is the ideal gas constant, and T=Temperature), which is experimentally observed, using statistical mechanics. But this turns out to be an approximation, and depending on the circumstances, you can have deviations from the ideal gas law. To argue that since there is a "controversy" about whether PV really does equal nRT, and therefore it should not be taught in school, (or worse yet to argue that it is a "fraud" to teach the ideal law or other aspects of chemistry as being "true"), is not very different, in my opinion, from saying that because there is a "controversy" in evolution, it must logically follow that the whole theory is completely wrong (and, it just so happens, their hopes go, that the only alternative left on the table is belief in some sort of Intelligent Designer Supernatural Creator Something, who operates outside the realm of nature, but we won't mention any Names).
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Wells is a Senior Fellow in the Center for Renewal of Science and Culture, and has said that he has committed his life to "destroying Darwinism", and this was his motivation for getting his second Ph.D. (His first Ph.D. was in theology, from Yale University, and his undergraduate training was in theology from Rev. Moon of the Unification church.) Thus, when Wells states in the preface that he first realised that textbooks were not being honest about presenting evidence for evolution, one has to consider that this is after he has spent many years determined to fight and destroy evolution. Perhaps he might not have been as objective as it sounds in the preface, when he states "During my years as a physical science undergraduate and biology graduate student at the University of California, Berkeley, I believed almost everything I read in my textbooks".
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A cynic might suggest that the REAL purpose of the book is not to actually provide scientific documentation, but instead to instill a "reasonable doubt" amongst those in the general population who are ignorant of the subject area; if this were his goal, then I think he is likely to be successful. Needless to say, this book is selling quite well amongst the fundamentalist Creationist circles in the U.S.
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However, in all fairness, it is certainly possible for even a devoted critic to be right in his criticism. Is Wells right in his claims presented in the book? I think not, but before I respond to them, I want to examine his case a bit further. Suppose, for the sake of the argument, that he is correct, and that all of the "Icons" of evolution are false. What sort of alternative explanation is offered to explain HOW life has changed with time? In Chapter 3, Wells readily accepts 3 billion year old bacteria fossils. So the question is, how does one explain the transition from the first single bacterial cells of more than 3,500,000,000 years ago to the abundance of life we see around us today? At least the Creationists offer some sort of Biblical creation scenario, in which the world was created 10,000 years ago, and claim that much of what we see in the fossil record is the result of a global Genesis flood. But all that is offered in "Icons of Evolution" is an attack on evolution, with no alternative explicitly mentioned, although the idea of humans being "Created with a purpose" [by an Intelligent Designer Someone] is brought up in the conclusion.
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Reading between the lines, it is evident that Wells believes in some sort of Intelligent Designer theory. "Icons of Evolution" is in a sense the third book in what could be called the "wedge triology" of books. The first was "Darwin's Black Box", published in 1996, by Michael J. Behe; this was followed by "THE DESIGN INFERENCE: Eliminating Chance through Small Probabilities", in 1998, by William Debenski; and now "Icons of Evolution", published at the end of 2000, by Jonathan Wells. All of these books have been encouraged by Phil Johnson and the Discovery Institute. The "wedge strategy" is a well-organised attempt to bring back the Biblical view of the purposeful creation of life by an Intelligent Designer, into the U.S. public schools. (For more on this, see the article by Keith Langford). This is essentially the teaching of creationism, under the guise of science. This is why I say that the Intelligent Design theory is a form of "Stealth Creationism". Thus, this book is part of a larger strategy, aimed at convincing the general public within the U.S. that evolution should not be taught in the U.S. schools.
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All three of these books have a common theme: Biochemistry cannot account for the origins of complex biochemical systems (Behe), Information theory cannot account for the origins of biological information (Dembski), and now we are told that Evolutionary theory cannot account for the origins of life (Wells). All three also depend on two pieces of logic which are perhaps good in convincing people of a political argument, but not really something that one would want to use as part of a scientific argument. First, all three of these books make certain presuppositions which need careful examination. Is it REALLY true that there are ONLY two choices, current science or Divine Intervention? The reasoning goes like this: IF the current science is wrong, THEN it is a perfectly reasonable and logical alternative to invoke SUPERnatural explanations (e.g., intelligent designer somethings, spirits, magic, and/or gods). I have written an article about alternative, SCIENTIFIC explanations for the origins of Behe's complex biochemical systems (J. Theor. Biol., 202:111-116, 2000), and Dembski's work has been discussed elsewhere. The second fault in their argument is that they use the creationist strategy of an appeal to the ignorance of the reader - MOST people won't know about evolutionary theory, so we can just make up items that don't really exist, say things that really are not true, and quote scientists out of context, and they'll probably never know the difference. Like I said, this will certainly work if you are wanting to convince a large uneducated group of a political point, but I don't think it qualifies as science.
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The claims in this book deserve an examination - not only because of their scientific merit, but also in light of the larger political ambitions of this book. Let's look at the facts - are the claims of fraud that Wells makes true? Obviously, a complete response to all of the Icons would require a book, and certainly would take more space than is available in this review. I will briefly examine some of the different "Icons" here.
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The first "Icon of Evolution" actually isn't really about evolution at all. It is about the origins of biochemicals necessary for life, or the field of science known as abiogenesis. The question of how the first biomolecules were formed and where they came from, is of course important in terms of explaining the origins of the first cell. But this is not the same subject as the question of evolution of living organisms. But since Wells later associates evolution with "materialism", and the subject of the book is to attack this materialistic belief, then it seems reasonable to start with a look at the origins of biological molecules. This also creates a common thread with the two other "wedge books", Darwin's Black Box, and The Design Inference, which claim that the origins of biological molecules and information is simply too unlikely and complicated to be explained without the invocation of some sort of miracle.
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Wells' argument is the same complaint made by creationists: Stanley Miller's experiments which produced amino acids from a "primitive earth atmosphere" are invalid, because the initial experiments done in 1953 used a strongly reducing environment, and it is likely that the early atmosphere was only weakly reducing. Yes, it is true that the yields are not as good in a more realistic atmosphere, but this is simply not the same as saying that there are no yields at all. There are several chapters dealing with this very subject in the book "The Molecular Origins of Life", edited by Andre Brack. After a long discussion of the amount of various gases in the early atmosphere, the conclusion of a chapter on "The early atmosphere as a source of biogenic compounds", is that "a weakly reduced atmosphere supplied with methane from a highly reduced mantel, could have produced a large, endogenous source of organic molecules on the early earth." In this same book is also a chapter by Stanley Miller, and he has repeated his experiments under the conditions now believed to be that of the primitive atmosphere, and finds he can still generate many organic compounds. He gives an open and honest account of the present status in the field. This, combined with the other 17 chapters in the book give a very good and current overview of abiogenesis. I would gladly recommend reading of "The Molecular Origins of Life" for anyone interested in further exploring this area. I think it is unfortunate that Wells does not include this book in his chapter references.
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A. The Fossil Record
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Contrary to what Wells would have you believe, there IS indeed a large body of evidence supporting evolution, not only of animals, but of life before the Cambrian period. For example, have a look at the fossil record - not what the creationists say, based on the fossil record 150 years ago, but recent comments the scientists themselves have to say about it (for example, see "The Triumph of Evolution" by Niles Eldredge). We can see a gradual change in the fossil record, from the earliest bacteria fossils of 3.8 billion years ago, to the simple single-celled bacteria which formed ecosystems 3.5 billion years ago, to Archaebacteria fossils 2.9 billion years ago, to multi-cellular eukaryotes fossils of 1.7 billion years ago to fossils of higher algae 1.2 billion years ago, to the "Ediacaran fauna" (the first fossils of large organisms) 650 million years ago, to the Cambrian fossils of about 500 million years ago. Wells is willing to accept much of the fossil record, including bacteria more than 3 billion years ago. His only problem is with "Darwinian evolution". I have outlined some of the major events in the fossil record on the timeline in the figure below. The dates in this figure are mainly from three sources: "The Triumph of Evolution and The Failure of Creationism", by Niles Eldredge; "Evolution" by M. Strickberger; and "The Molecular Origins of Life" by Andre Brack (see references below for the full details).
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This figure shows that there is in fact a progression from relatively simple, single-celled bacteria, to single-celled eukaryotic cells, to muli-cellular eukaryotic cells, to the first plants and animals. I am somewhat surprised to see that Wells seems happy with accepting 3 billion year old bacteria, but not any implication of evidence for "descent with modification". For example, consider his description of the "Cambrian explosion".
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I know some people would define "long history" differently, but my own personal feelings are that 160,000,000 years of fossil history should be considered "long". According to Niles Eldredge, who has studied extensively the fossil record, the "geologically instantaneous" appearance of animals in the fossil record that Wells discusses happened over a long time span.
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Furthermore, the animals of the Cambrian period really are quite a bit different from the modern animals, and there is an ADDITIONAL 500,000,000 years of evolutionary history within the fossil record, of these changes. The fossil record also includes five major extinctions, where at least 70% of the species became extinct. Wells doesn't talk much about extinction, although the species today represent only a tiny fraction of the total number that have lived and become extinct in the three billion year history of life on this planet.
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B. Molecular phylogeny
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On the accuracy of dates using amino acid "clocks". Wells is surprised at a difference of 600 million years between different estimates based on molecular phylogeny vs. the paleontological evidence. I'm not that surprised, because I know that the "molecular clock" dating method makes some initial assumptions that simply are not very likely to be true. I think Wells should read "Tracing the roots of the Universal Tree of Life", by William Schopf, (from the book "The Molecular Origins of Life"). In this chapter, there is a table comparing geological evidence vs. the "amino acid clock". For three of the bacteria listed in the table, the difference is about 2.0 billion years!. Schopf concludes that the geological evidence is more compelling, and as a molecular biologist, I tend to agree with him.
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Horizontal gene tranfer. Wells is certainly right in that the exchange of genes from one organism to another complicates the phylogenetic picture. It is possible to construct different phylogenetic trees for each individual protein in the entire genome of an organism, and sometimes many different proteins (in the same organism) will have different phylogenetic trees. (see, for example, the paper by Thomas Sicheritz-Pontén and Siv Andersson, Nucleic Acids Research, 29:545-552, 2001). Sometimes larger fractions of the genome can come from other sources. For example, we recently published a paper showing that roughly one-fourth of the DNA from the genome of the bacteria Thermotoga maritima came from an Archaebacteria, possibly of the genus Pyrococcus. Many of the genes in bacteria have come from other organisms. This is also true in yeast and other fungi, although I think it happens less often in animals. (Plants are a bit strange anyway, in that sometimes they are so variable in chromosome number, that it is difficult to figure out how many chromosomes a species has.) In terms of the phlogenetic trees that Wells is interested in (e.g., plants and animals), horizontal gene transfer is much more rare - in part because it is simply much more difficult (and less likely) for the transferred DNA to find its way into the germ cells (sperm and eggs). Bacteria are single cells, and if the DNA gets in, then it will be passed on to the next generation. But in order to have horizontal gene transfer in a frog, for example, the DNA would have to do more than enter a frog cell - it would have to specifically incorporate into a sperm or egg cell, and if it was very much DNA at all, it would not form fertile offspring. But doesn't horizontal gene transfer sound like evidence for changes in the DNA sequences of organisms, and a possible mechanism for evolution? I am not sure whether it is really fair to say on the one hand that horizontal gene transfer happens, and then turn around later and say that there's no evidence for evolution.
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Does the discovery of the "Three SuperKingdoms" of Archae, Bacteria, and Eukaryotes turn upside down the idea of descent with modification? Aristotle divided living things into plants and animals. This classification was used for more than two thousand years, until, with the advent of the microscope and the discovery of microscopic organisms, a third category of "Protista" was added last century, by Ernst Haeckel (of embryo fame in this book!). Then in 1959, Robert Whittaker proposed the "five kingdom" system, which is the one still in use today. The discovery of the Archae "SuperKingdom" does not in any way diminish the evidence for the 5 Kingdom classification - it merely adds a description of life that we had previously neglected. Wells is correct that many biologists were surprised when Carl Woese first proposed the idea that there two very different forms of "bacteria" and they are more different from each other than plants and animals. However, what is very clear from the phylogenetic trees is that there is a common relationship between ALL living organisms, and the best scientific theory which can explain this is descent with modification. For more on this, I would encourage the interested reader to have a look at the "Five Kingdoms" book, by Lynn Margulis, and additional references cited at the end of this review.
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The bottom line. The point of this chapter is to show that comparison of sequences between organisms does not support the idea of descent with modification. Although Wells has presented some interesting problems, he has not shown that descent with modification rarely happens (or can NEVER happen), but that sometimes at the level of individual genes, molecular phylogeny is difficult to interpret. It is certainly a good thing to question how valid the assumption that all the genes in an organism will share the same lineage. However, it has proven to be a general rule that very often one can indeed find a good relationship between the similarity of a given gene between two organisms, and their phylogenetic similarity. Of course there are exceptions, and they should be studied. Life is very complicated, but exceptions do not mean that we cannot see any general trends. And it is quite clear from molecular studies that descent with modification occurs. To deny this is to be dishonest.
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In the last chapter, Wells makes his case for trying to stop funding for the "Darwinians". He says that scientists are knowingly faking evidence for evolution, and are guilty of fraud. For example, consider what he has to say about Stephen Jay Gould:
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This sounds pretty serious indeed. Is it really true that Stephen Jay Gould has known about this for decades? Yes, it's true. How does Wells know this? Here's the rub - because Gould has published a best-selling book on the subject, in 1977 [see ref#16 below]- more than 20 years ago, and the book can still be found readily in many used book shops today (as Wells even mentions in his book). Gould has also criticised Haeckel's fake drawings in several of his articles and books published since then. So just to make sure this is clear: Gould is guilty of fraud because he "sat by with his lips sealed" (preface) - even though he wrote a best-selling book about it 20 years ago and has often talked about the subject passionately, given the opportunity? I don't think Wells' case of fraud against Gould would hold up in a court of law - let alone even hold up to basic logic.
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I am willing to accept the premise that there are some commonly used examples of evolution which are more complicated in real life than is often portrayed. The case of the Four-winged fruit fly mutation is a good example. Although it has sometimes been held up by some as an example of a mutation which results in a gain of function, when one takes a larger perspective (compared to other insects) this mutation can be seen as a reversion. The reason for the additional wings is a mutation in the ubx gene. Drosophila belongs to the Diptera order of insects, which have two wings, whilst most other insects have four wings. From an evolutionary perspective, the reason fruit flies have two wings (instead of four) is due to a LOSS of function present in its ancestors. Thus, if this were used as an example of a beneficial mutation, then great care must be taken to explain this in its proper context. I had anticipated that Wells was onto this, and would try and set the record straight, and then go on to talk about the importance of the hox genes (and the homeobox genes in general) in terms of developmental biology and the evolution of different types of body plans. The reasoning in the chapter goes like this:
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Preamble:
- Nearly all mutations are bad, and neutral mutations are rare.
No one has ever documented a "good mutation" in Drosophila.
- Biochemical mutations in bacteria aren't really MUTATIONS after all.
Main "Icon": Four winged fruit flies
- The Four-winged fruit fly could never happen in the wild.
- Four-winged fruit flies are reflections of an earlier ground state.
- "Four-winged fruit flies are no better than a two-headed calf" in terms of providing evidence for evolution.
Bizarre conclusion:
- Mutations aren't REALLY the raw material of evolution
- The idea that DNA makes mRNA makes proteins and that genetics plays an important role in development are part of a "Darwinist conspiracy" to try and cook up false evidence for evolution.
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I think that Wells stops a bit short in his history of variations - he only brings the reader up to the 1970's - imagine someone giving a history of computers and stopping 30 years ago! A lot has happened in the field of molecular biology in the past 30 years. There has been an explosion in the amount of sequence information. The "variations" talked about here are ultimately the result of variations in DNA sequences. The growth rate of biological sequences is breath-taking. For example, in 1970 we could only sequence very short pieces of DNA, and this took an enormous amount of time and effort. Even dreaming of sequencing the human genome was difficult. By 1980, it was possible to sequence tiny bacteriophages, and it would take more than a MILLION years to sequence the human genome, and perhaps a thousand years to even sequence a bacteria! By 1990, sequencing had improved (in large part by a very large investment of the human genome project - funded at $200,000,000 a year for 20 years!, and it would take a "mere" THOUSAND years to sequence the human genome. This month (January, 2001), a "draft" of the human genome will be published. We can now sequence the DNA from an entire bacterial genome in just a few hours! Of course, the problem comes in analysing all this amount of data.
 The point is, if Wells wants to talk about variations - which of course is variations in the DNA sequence - then he should take into account the explosion of information that is presently happening.
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Wells wants to claim that the mutation which results in flies having four wings instead of two is not quite what it's cracked up to be. Fine, let's see the evidence for what he says, and evaluate it accordingly. My friend told me this was a book written by a "noted developmental biologist", and Wells says in the introduction that this chapter was reviewed by none other than Edward B. Lewis, who won the Nobel prize for his work described here, so I was looking forward to hearing a brief introduction into the molecular biology of the subject, followed by an outline of his arguments, and then a summary of the case. Instead I found a strange (in my opinion) useless collection of misinformation about Drosophila genetics, which taken as a whole left me quite bewildered as to what on earth Jonathan Wells is trying to say. Wells also conveniently "forgets" to mention that there are more than 300 different mutations in this gene that have been characterised. But what is worse (in my opinion) is that Wells never talks about the larger picture of the Ubx gene in terms of homeobox genes and their role in evolution of morphology. He seems to totally miss the point of the significance of the four-winged fly, which is in terms of a family of genes (known as hox genes) found not only in fruit flies, but in every other animal (and plant and fungi) examined, and how changes in these genes result in morphlological changes in all the various organisms. I still remember the wonder and amazement the first time I read that the genes are oriented "head to tail", so that the genes at one end would affect structures in the head, and the other end, genes expressed in the tail. There are several well-known mutants of Drosophila in these genes, in addition to the four-winged fly. For example, a fly with an antenna replaced with a leg. Wells dismisses these as "freaks", and says they say nothing about evolution.
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Mutations in these genes results in different body plans - or so goes the prediction. Is there any evidence to confirm this? I think so - for example, the Hox gene cluster has undergone a gene duplication between invertebrates and vertebrates (this is a common occurrence in evolution - gene duplication which allows experimentation with the second copy). The evolution of the Hox genes in vertebrates has been detailed in a recent article in Nature magazine, entitled "Conservation and elaboration of Hox gene regulation during evolution of the vertebrate head" (Nature, 408:854-857, (2000)). In the abstract, the authors state "Here we present evidence for the conservation of cis-regulatory mechanisms controlling gene expression in the neural tube for half a billion years of evolution, including dependence of retinoic acid signaling." So the four-winged fly is an interesting side show - an example pointing to the hox genes, but the evolutionary significance lies in tracing the history of the genes themselves. To put this in perspective, Walter Gehring spends a single paragraph (out of more than 200 pages) describing the four-winged flies in his book on the homeobox genes (see Gehring, 1998).
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Apparently Wells hasn't done his homework on this mutation. It looks as though he doesn't understand the significance of the hox genes (or the homeodomain genes in general). This fact could certainly be used to build a more credible case, had he grasped it. There are several good entry points into the literature for those interested in learning more about the hox genes. For example, see "Insect evolution: Redesigning the fruitfly", (Current Biology, 9:R86-R89, 1999), for a good overview of the subject. But let's try and put this in perspective here. I've just done a search on PubMed, a good database of references, with more than 11 million articles. Here is the result of two different searches:
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"Four winged fruit fly" - 5 articles
"homeobox evolution" - 572 articles
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Based on these results, does it sound like the four-winged fly is really THE "Icon" of evolution here? With more than ONE HUNDRED times as many articles about homeobox and evolution, I'd say perhaps there's more to the story about evolution than merely the four-winged fly.
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In short, Wells has not done his homework, and is relying on an appeal to ignorance of the readers, rather than trying to build up a logical, rational compelling argument based on what is known about the subject. This was particularly evident in the bizarre tangent he takes towards the end of the chapter, where he seems to claim that the idea that genes play a role in development (or even that DNA makes RNA makes protein) is some sort of conspiracy amongst "Darwiniains". Does Wells really think that it is not true that DNA makes RNA makes protein? I am left quite puzzled as to the real intentions of why Wells wrote this chapter. In my opinion, it was certainly not to inform the reader, but more to try and pull the wool over the eyes of those who are not familiar with the recent developments in developmental biology, his alleged area of expertise. Exactly WHY Wells would want to write such a deceptive chapter is not quite so clear to me, although I suspect it is due to his religious opposition to the "meaningless" of Darwinian evolution. This is evident when he refers back to this chapter at the end of the book, as saying that he has shown that the four-winged fruit fly is an example of how mutations could never produce the raw material for evolution. But he totally misses the point that this is a remarkable example of how a single gene can affect major morphology in an animal - mutations in a single gene can result in four wings, instead of two.
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Wells tries to hide the evidence for evolution of humans, by saying that it is all subjective, so we really cannot believe what the paleontologists tell us. There are three books I would recommend reading for more information about human evolution. The first is "The Triumph of Evolution" by Niles Eldredge. Compared to the 3.5 BILLION year history of the fossil record, humans have just come on the scene in the last blink of an eye. Here is how Eldredge explains the fossil evidence for human ancestors:
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I would also recommend reading Jared Diamond's book, The Third Chimpanzee, where he discusses human evolution. Diamond says that 20,000 years ago, a space alien visiting the planet earth would have put humans as merely a third species of chimpanzee - that it is only recently with the development of culture that we have managed to change the face of the planet (and have exploded in our population). Finally, I would recommend reading GENOME: The Autobiography of a Species in 23 Chapters, by Matt Ridley. From a genetics point of view, we are only a tiny bit different from chimpanzees - less than 1% at the level of DNA. The difference is mainly in the timing and expression of genes. We are a "distinct" species as humans in that we have one LESS chromosome than the chimpanzees and other "great apes" - this is because two of their smaller chromosomes have fused together to form a larger chromosome. This would mean that humans could no longer produce fertile offspring with other members of chimpanzee family, thus creating reproductive isolation. This is exactly the type of thing predicted and expected from evolution.
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People in the fields of medicine or agriculture don't really need to know anything about evolution, according to Wells. A medical doctor doesn't need to know about evolution - he just prescribes antibiotics to a patient, and the patient is cured.
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Just this past week I read an article in the newspaper about the dangers of antibiotic resistant bacteria, and one of the main causes is that doctors don't seem to appreciate that by over-using the antibiotics, they are effectively causing a major problem by selecting for bacteria with antibiotic resistance. Even the newest antibiotics are proving to be of no avail to some resistant strains. Ignorance of evolution can be very costly in terms of disease. As another example of the relationship between evolution and medicine, I would recommend reading "At War Within", by William R. Clark, in which he describes our immune system as a type of Darwinian selection in "real time".
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And does Wells really think that the "green revolution" had nothing at all to do with our understanding of the molecular basis for evolution in plants?
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(I should add that the "greatest defeat" didn't last for long - the Kansas farmers chose not to re-elect the members of the school board that removed evolutionary biology from the state exams.) Domestic breeding has been around long before Darwin, but I don't think we had quite the same high yields back then as we do today, using crops that have been engineered using an understanding of evolutionary biology.
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It is true that Gregor Mendel, (who was a contemporary of Darwin), might not have heard of evolution, but certainly "Darwinian evolution" was well known by the time that the word "gene" was coined in 1909 (by the Danish scientist Wilhelm Johannsen). It is also true that early on it looked as though genetics was at odds with evolution, but as most every biology student knows, this controversy was settled in the 1930s and 1940s, and by the time of the discovery of the structure of DNA in 1953, the scientific community could see for the first time that evolution happens by a change in DNA sequence. I certainly have no problem teaching my students that understanding evolutionary mechanisms is a necessary and vital component of genetics and molecular biology. Nor do I think Dobzhansky's claim that "nothing makes sense except in the light of evolution" is an understatement.
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Appendix I contains an evaluation of several popular biology textbooks. (This list is similar to a previous report by Jonathan Wells.) Most of them receive a grade of an "F". Using the same type of criteria from the Appendix in "Icons of Evolution", I would give Wells' book a grade of an "F", because he distorts and mis-quotes scientists and does not write to encourage people to build upon a logical foundation, but rather to blindly accept his "proofs" that evolution is wrong. Wells offers no alternative scientific theory to explain the fossil record. If not by Darwinian evolution, then HOW did life gradually change from single-celled simple bacteria 3.5 billion years ago (which Wells says he accepts), to the present explosion of life in all of its complexity all around us? In short he fails to convincingly demonstrate to me, as a fellow molecular biologist, that most of the "Icons" are really the essential foundations of evolution he claims, and he offers no compelling evidence to me that these are indeed 'frauds'. However, I am seriously concerned that Wells claims himself to be a "molecular biologist", and yet questions the very foundations of molecular biology (DNA makes RNA makes protein) as some sort of Darwinist conspiracy. Since Wells is interested in "origins", perhaps he should read The Eighth Day of Creation by Horace Freeland Judson, for a refresher on the origins of molecular biology.
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"The Wedge Triology"
- Darwin's Black Box: The Biochemical Challenge to Evolution, by Michael J. Behe, (The Free Press, New York, 1996). My review of the book Amazon.com Barnes&Noble
- THE DESIGN INFERENCE: Eliminating Chance through Small Probabilities, by William A. Dembski, (Cambridge University Press, Cambridge, England, 1998). Amazon.com Barnes&Noble A few of my own comments about this book.
- Icons of Evolution: Science or Myth?, by Jonathan Wells, (Regnery Publishing, New York, 2000). Amazon.com Barnes&Noble
Other Books
- Vertebrate Palaeontology, by Michael J. Benton, (Blackwell Science, Oxford, 2000). Amazon.com Barnes&Noble
- AT WAR WITHIN: The Double-Edged Sword of Immunity, by William R. Clark, (Oxford University Press, Oxford, 1995). Amazon.com Barnes&Noble
- The Triumph of Evolution... And the Failure of Creationism, by Niles Eldredge, (W.H. Freeman Company, New York, 2000). My reveiw of this book. Amazon.com Barnes&Noble
- THE THIRD CHIMPANZEE: The Evolution and Future of the Human Animal, by Jared Diamond, (Harperperennial Library, New York, 1993). Amazon.com Barnes&Noble
- THE EIGHTH DAY OF CREATION: Makers of the Revolution in Biology, by Horace Freeland Judson, expanded edition, (Cold Spring Harbor Laboratory Press, New York 1996). Amazon.com Barnes&Noble
- Discovering the first complex life - The GARDEN of EDIACARA, by Mark A.S. McMenamin, (Columbia University Press, New York, 1998). Amazon.com Barnes&Noble
- The Five Kingdoms: An Illustrated Guide to the Phyla of Life on Earth, by Lynn Margulis, (W.H. Freeman Company, New York, 1998). Amazon.com Barnes&Noble
- Molecular Evolution: A Phylogenetic Approach, by Roderic D.M. Page and Edward C. Holmes, (Blackwell Science, Oxford, 1998). Amazon.com Barnes&Noble
- GENOME: The Autobiography of a Species in 23 Chapters, by Matt Ridley, (HarperCollins Publishers, New York, 2000). Amazon.com Barnes&Noble
- EVOLUTION, by Monroe W. Strickberger, 3rd edition, (Jones and Bartlett Publishers, Sudbury, Massachusetts, 2000). Amazon.com Barnes&Noble
- Ontogeny and phylogeny, by Stephen Jay Gould, (Cambridge, Mass. : Belknap Press of Harvard University Press, 1977)
- The Beak of the Finch, by Jonathan Weiner, (Vintage Books, A Division of Random House, Inc., New York, 1995). Amazon.com Barnes&Noble I would encourage the interested reader to read this Pulitzer Prize winning book and decide for themselves the validity of the comments Wells makes about it in chapter 8 of "Icons of Evolution".
- At the water's edge - macroevolution and the transformation of life, by Carl Zimmer, (The FreePress, New York, 1998). Amazon.com Barnes&Noble
- Lankford, Keith,
"The Wedge: A Christian Plan to Overthrow Modern Science?"
Doubting Thomas, Feature story number 6, April/May, 1999.
Accessed on-line from the following URL: http://www.freethought-web.org/ctrl/archive/thomas_wedge.html
- Thomas Sicheritz-Pontén and Siv G. E. Andersson,
"A phylogenomic approach to microbial evolution"
Nucleic Acids Research, 29:545-552, (2001).
Link to other reviews of Icons of Evolution
Link to recent papers I've written about DNA structures
Last modified on: 8 February, 2002 by Dave Ussery