Jonathan Wells apparently felt the sting of my rebuttal of his assertions about Hox gene structure, because he has now repeated his erroneous interpretations at Dembski’s creationist site. His strategy is to once again erect a straw man version of biologist’s claims about genetic structure, show that biologists have refuted his dummy, and claim victory. The only real question here is whether he actually believes his historical revisions of what we’ve known about Hox genes, in which case he is merely ignorant, or whether he is knowingly painting a false picture, in which case he is a malicious fraud.
…one of evo-devo’s most widely advertised claims has turned out to be false. Hox genes, which are important in embryo development, are lined up on the chromosome in the same order in which they’re expressed along the body axis, and the order is the same in the fruit fly Drosophila melanogaster as it is in vertebrates. For years, Darwinists have been claiming that this similarity in Hox gene order provides powerful evidence for the common ancestry of insects and vertebrates. But biologists have now discovered that the order of Hox genes in other species of Drosophila is different; apparently, the order in Drosophila melanogaster is a relatively recent acquisition. In the jargon of evolutionary biology, it is “derived” rather than ancestral.
No, this claim that the Hox genes are identical in order in every animal is an invention of Wells — it is most definitely not “one of evo-devo’s most widely advertised claims” — and it is false. “Creationist wrong again” is not something newsworthy, though.
As I pointed out in the earlier article and will reiterate now, we’ve known for a long, long time that the Hox genes (even before they were called Hox genes!) in Drosophila are not contiguous, but are broken into two complexes, the antennapedia complex and the bithorax complex. Seriously—read Ed Lewis’s brilliant Nobel lecture to see what I mean; for Wells to claim that we “have now discovered” that the Hox genes aren’t arrayed in precisely the same linear order in every animal when we knew this from work in classical genetics, when Lewis had figured this out back when I was in grade school, is disingenuous and profoundly ignorant for someone who claims expertise in developmental biology.
Wells also takes quotes from me out of context to try and play as if I’ve acknowledged his scholarship, when exactly the opposite is true—I’m pointing out that he is deeply in error when he makes claims about what evo-devo (heck, genetics and developmental biology) have said about the Hox genes.
Myers acknowledged that “it is true that there are significant rearrangements in the Hox genes,” but he took me to task for neglecting to point out that “the evidence in the paper shows a pattern of inheritance of structure and variations from structure in the Hox genes… The paper is trying to explain the mechanism behind this slow pattern of changes in the Drosophila lineage, and it makes a good argument.”
Every biologist who has looked at the literature for Hox evolution knows about the changes in structure. We’ve known that Drosophila is a highly derived genus for as long as we’ve been working on it. What I was chewing Wells out for was his ignorant assumption that we’ve been claiming that Hox structure is inviolate, so that variations show one of our “most widely advertised claims” false.
He might as well go all the way. Why not announce the death of Darwinism because scientists admit that humans did not evolve from rutabagas? That’s equivalent to what he has done here: he has invented a false claim, one known to be wrong by decades of research, one not made by biologists, and then found a recent paper that explores in a little detail the exceptions from Wells’ false claim, and he does a victory dance over the ‘disproof’ of evo-devo.
Actually, the 2006 paper I cited includes the data to prove my point that Hox gene order in Drosophila melanogaster is derived rather than ancestral, but the paper also bravely tries to interpret the data in a Darwinian context. I didn’t mention this; if I had, I would have explained why I think the paper’s attempt to protect Darwinian orthodoxy fails. No matter. Myers ignored the point I made and criticized one I didn’t make.
“bravely tries to interpret the data in a Darwinian context”?
Ay-yi-yi. The paper is not making an “attempt to protect Darwinian orthodoxy”. It is using evolutionary theory to assess the phylogeny of a clade of flies, and using a property of the Hox cluster, its greater freedom from constraint in these rapidly developing species, to infer properties of gene regulation. The variation in structure that Wells claims biologists have been denying is precisely the phenomenon that the authors are studying!
Read my summary. In particular, look at the diagram from the paper that maps out the pattern of breaks and inversions and deletions in the Hox cluster—it reveals a beautiful historical pattern of evolutionary change. I also described work in chordates on the same phenomenon, documenting variations in Hox organization that reveal a) patterns of descent, and b) positional constraints on gene regulation.
All we’ve really learned from Wells’ forays into the scientific literature is that the Intelligent Design creationists possess only caricatures of what evolutionary biologists say, and that their caricatures are completely false. The only veracity that has been impeached here is that of Jonathan Wells.