A few weeks ago I blogged about an important series of papers on the evolution of the glucocorticoid receptor gene [see You Can't Go Home Again]. This is work from the Thornton lab and it shows the effect of accumulating neutral mutations over millions of years. I like the papers because it demonstrates clearly where Michael Behe goes wrong in his latest book The Edge of Evolution.Carl Zimmer liked the papers as well and he wrote about them in a great big blog called The New York Times [see Can Evolution Run in Reverse? A Study Says It’s a One-Way Street]. I hate it when he does that. It makes me look bad.
Not surprisingly, Michael Behe read the papers. Surprisingly, he actually thought they helped his case rather that hurt it [see Nature Publishes Paper on the Edge of Evolution]. I was going to follow up on this since it was the reason I brought the papers to your attention in the first place. Now I'm glad I didn't because Carl Zimmer has done a much better job.
Carl asked Joe Thornton to comment on what Michael Behe said on the DISCO website. Thorton replied with a devastating put down of Behe that Carl has posted on The Loom: The Blind Locksmith Continued: An Update from Joe Thornton.
This is a really important article for a variety of reasons. You must read it if you want to learn about modern concepts in evolution.
Here's an excerpt from Thornton's letter that should induce you to visit the rest of the article.
Thanks for asking for my reaction to Behe’s post on our recent paper in Nature. His interpretation of our work is incorrect. He confuses “contingent” or “unlikely” with “impossible.” He ignores the key role of genetic drift in evolution. And he erroneously concludes that because the probability is low that some specific biological form will evolve, it must be impossible for ANY form to evolve.
Behe contends that our findings support his argument that adaptations requiring more than one mutation cannot evolve by Darwinian processes. The many errors in Behe’s Edge of Evolution — the book in which he makes this argument — have been discussed in numerous publications.
In his posts about our paper, Behe’s first error is to ignore the fact that adaptive combinations of mutations can and do evolve by pathways involving neutral intermediates. Behe says that if it takes more than one mutation to produce even a crude version of the new protein function, then selection cannot drive acquisition of the adaptive combination.
[Photo Credit: Joe Thornton by Jack Liu Photographer]
