On August 14, the intelligent-design (ID) advocate William Dembski spoke here at The University of Chicago. He was brought here by the Computation in Science seminar (I believe it was his Ph.D. advisor here who sponsored or invited him), and his topic was “The conservation of information in evolutionary search.” The video of his talk, a bit longer than an hour, is at the bottom. I didn’t go, as I believe I was out of town, but were I here I wouldn’t have gone anyway as I was working hard on the Albatross. I’ll may get around to watching the talk, but, as you can see below, an evolutionist familiar with the material says there’s nothing new in it. The IDers will of course scream bloody murder because I’m presenting a critique without seeing the talk, but it’s not my critique. It’s Joe Felsenstein’s. Rest assured that they’ll put up some criticisms of Felsenstein at Uncommon Descent within a day or two.
Over at Panda’s Thumb, Felsenstein, renowned evolutionary geneticist and ID critic, did the yeoman’s work of watching the video and then analyzing it in a post called, “Dembski’s argument in Chicago—New? Persuasive?” Felsenstein’s answer on both counts is “no!” Felsenstein has saved most of us the trouble of watching the video, for he concludes that Dembski’s talk is just a rehash of old arguments that have been debunked some time ago.
I won’t rehash Joe’s post, for, as usual, it’s clearly written and should be intelligible if you know something about evolution and population genetics. But let me just point out what Felsenstein sees as Dembki’s two major errors (the model is actually by Dembski and Robert Marks; I’ll call it “Dembski’s model” for shorthand).
1. Dembski’s model depends on all possible genotypes of an organism having randomly assigned fitnesses, so that if you change a single nucleotide in a genome, the chance of improving it are exactly the same as if you changed every nucleotide. That’s insane. Changing every nucleotide will completely destroy your fitness (average reproductive capacity); changing one has at least some chance of improving it. Genotypes that are nearby in genotype space will have similar fitnesses, so the “genomic landscape” is not horribly rugged, as Dembski assumes, but smooth. The “ruggedness” assumption is needed to show that natural selection can’t work, but it’s a lousy assumption. Go see how Dembski justifies the assumption that sometimes natural selection can work.
2. Dembski’s model requires that each nucleotide (and trait) in the genome interacts strongly with every other nucleotide (and trait), which simply can’t be the case. The developmental network almost guarantees that you can change some parts of an organism without affecting other traits. For example, changing the coat color of a bear from brown to white (as probably happened during the evolution of the polar bear) almost certainly won’t affect its musculature, shape of its toenails, or hunting behavior. Those things, if they change, would change independently, based on selection on other genes.
This is just a summary of what I see as the two main errors. Joe lists several others.
These criticisms have been made before, and Dembski is, according to the ID playbook, ignoring them. As Felsenstein says, there’s nothing new in the seminar. But I’ll put the video below for those of you who either keep atop these things or are masochists:
Conclusion: Shame on the University of Chicago for giving a platform to religiously-motivated arguments that were discredited a decade ago. I’m ashamed of my school.