To those of us who pursue it on the wing, evolutionary developmental biology provides the liveliest expression of evolutionary processes in action and offers us experimental access to the machinery underlying the evolutionary change of form. Workers in the field may be unpleasantly surprised to find that a recent manifestation of creationism has settled upon evo-devo as something altogether different -- a major platform for creationism. Such is the case presented in the writings of Jonathan Wells (2000), author of Icons of Evolution (2000), who asserts that embryology is the Achilles' heel of Darwinism.

[[Here follows a synopsis of young earth creationism]]

Until recently, young earth creationists have dominated the political arena. However, the rise of another species of creationism, intelligent design, marks a new phase in creationist activity. So-called intelligent design creationism constitutes a sort of intellectual upper crust of the movement.

[[Here follows a description of ID as a politically and religiously motivated movement]]

Let us return to Wells and his abuse of evo-devo. 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 attacks what he sees as major developmental icons. He avers that the concept of homology is in dire crisis .... Wells and Nelson (1997) took a detailed look at this issue [that homologous structures can arise from different developmental paths] in a paper. There I found my own work on direct and indirect development presented as one of the examples of the failure of development to connect with homology. I was surprised to note that what I thought was an exciting research problem of how developmental pathways evolve was being taken as evidence against evolution. ... So far, the naturalistic mechanisms proposed to explain homology do not fit the evidence. What logical gymnastics! If it's unexplained, it must be unexplainable by evolutionary biology. If it's unexplainable by evolutionary biology, it must require an intelligent designer. ...

A second developmental icon taken on by Wells is the case of Haeckel's embryos. ... Richardson et al. (1997) showed that Haeckel falsified the degree of external appearance of these embryos to exaggerate similarity of phylotypic stage. To Wells this means that scientists have long known that drawings showing similarities between fish and human embryos were faked, yet continue to use them as evidence of evolution. ... Clearly Haeckel did a dishonest thing with his drawing. Does this mean that the concept of a phylotypic resemblance among vertebrate classes is a lie? The answer is a resounding no, and the great indignation raised by Wells is largely a pious smoke screen. The crucial point is not the superficial external appearance of embryos, but the sharing of major structural elements and their topological relationships. The phylotypic stage includes a dorsal nerve cord, somites, notochord, paired appendage buds, pharyngeal pouches, and sensory placodes. These are the elements that define the vertebrate developmental body plan. Are all vertebrates exactly the same at the phylotypic stage? No, of course not; development evolves, and so do features of the phylotypic stage--a point strongly made by Coyne
(2001).

[[Here follows a warning that although ID is in Raff's view bad science, it can prove potent politically. In particular, Jonathan Wells's book has "has already generated at least one state legislative bill."]]

Wells misuses the science he learned at Berkeley in a deceptive way to advance his single-minded goal. In discussing Darwinism on his web page, he says that his own work with a student showed him that DNA does not program the development of the embryo. This statement is supported by a disingenuous distortion of what is known about gene regulation in embryos. Despite some pictures of suitably iconic four-winged Drosophila, the discussion of genes and development in Icons of Evolution is even more shabby and misleading. All that matters is that the answer comes out right, so that Darwin's theory is incompatible not only with the evidence from embryology, but also with the evidence from the fossil record (Wells 2001). ...

[The article closes with a further warning about the danger of ID proponents derailing evo-devo.]

Coyne, J. A.2001. Creationism by stealth. Nature 410: 745-746.

Hughes, N. C.2000. The rocky road to Mendel's play. Evo. Dev. 2: 63-66.

Richardson, M. K., Hanken, J., Gooneratne, M. L., et al.1997. There is no highly conserved embryonic stage in the vertebrates: implications for current theories of evolution and development. Anat. Embryol. (Berl.) 196: 91-106.

Wells, J.2000. Icons of Evolution . Science or Myth? Why So Much of What We Teach about Evolution Is Wrong. Regnery Publ., Washington, D.C.

Wells, J.&Nelson, P.1997. Homology: a concept in crisis. Origins & Design Fall: 12-19.

[ 21 January 2002: Message edited by: Moderator ]

Haekel's drawings are a fake, early embryonic stages are not similar, and there are examples where development fails to connect with homology. Raff simply waves his hands, does a little dance, and proclaims that what evolution cannot explain today, may be explainable tomorrow. Well, thanks Raff for that pedantic, useless, and obvious point. But this argument does not establish that Wells is practicing bad science. No intelligent design proponent has ever stated that what may be true today, will still be true with new research. That may not be the case since science is tentative. What Wells and Paul are proposing is some alternative ideas that would be able to fit the evidence and explain what we observe. In my opinion, although their paper and Wells book does not imply this, what they are proposing is that certain genes and proteins were designed for orderly development in organisms. And this is what Raff is truly addressing, not whether the textbooks need editing, nor whether evolution does have some problems. But that Wells and Paul are IDists.

Yes, to a naturalist, Wells and Paul are religiously motivated. But there are several points people need to keep in mind.

This theory is falsifiable and testable unlike almost every other evolutionary theory out there. If, for example, histone H1 is not essential for development, then a hypothesis that states h1 was designed for development is falsified. On the other hand, a hypothesis where bicoid is designed for orderly development can be tested through viability analysis.

Don't dismiss it because it didn't appear in a scientific journal. It is very likely reviewers would confront Wells and Paul's paper with philosophical arguments rather than scientific evidence. The reason for this is it is so different from conventional science that it's easy to dismiss it as being metaphysical. But Wells has a serious hypothesis, and he's also conveniently provided us with a way to falsify it. Don't write him off as a religious crank just because he's an IDist, first show that he is in fact practicing bad science, and then write him off as a crackpot.

It is not true that Wells does not know a thing about evo-devo, just because he takes a unique view of the implications of development. His theory, as best as I can tell, shines a light on a problem in biology that goes as far back as Cuvier. I think it's about time an alternative model steps up to the plate. As the commercial goes, it is not just bold, it is also daring.

I think Wells deserves credit for comming up with a viable theory. First of all, it's crazy. But as Wolfgang Pauli is thought to have said to a fellow scientist, "We are all divided on whether or not your theory is crazy. I do not believe it is crazy enough." Secondly, it explains observed phenomena. Thirdly, it can make predictions. Fourthly, it's empirically testable. So who is practicing the bad science here?

[ 24 January 2002: Message edited by: Nelson Alonso ]