Dembski: Still wrong

William Dembski spoke at the University of Chicago in August, and a video of the talk is available. I tried to watch it, I really did, but I ended up skipping through most of it (one of the advantages of seeing it on youtube!). Here's my rather stream-of-consciousness monolog as I was flicking like a damselfly over the stagnant pond of his words:

"Get to the point, Bill. Skip. No biology. Skip. No biology yet. Skip. Wait, that model is anti-biology…evolution doesn't work like that. Watches a short segment. Nope, nonsense. Skip. No biology, skip. Oh, "specified complexity"…does he define it? Listens intently for a bit. Nope. Skip. Dawkins' weasel program? He still doesn't understand it! No biology, no biology, no biology, I'm done."

I know, that wasn't very informative, but then, neither was the talk. There were a few shots of the audience, and they didn't seem particularly enthralled, either.

Joe Felsenstein watched the whoooole thing, though, and has some very sharp observations on Dembski's model.

The most damning thing about the Dembski model, other than the fact that the authors seem to know absolutely nothing about biology, is that they build their argument on a bizarre foundation in which nothing in the genome is interconnected, where changes in a sequence lack any possibility of generating a graded response, and in which every point mutation has as much likelihood of generating a phenotypic variant as a complete scrambling of the genome. That's the tellingly abiological part of the story -- as Felsenstein notes, fitness is a random function of the whole genome:

What if, instead of changing one base, we took the drastic step of mutating all of the bases in the genotype at the same time? If the Bernoulli Principle applied, we would get to a genotype whose fitness was also chosen at random. So in that case, on average, that would be no better and no worse than changing just one base. In other words, when fitnesses are randomly assigned to genotypes making a single typographical error is exactly as bad as changing every letter in the text .

Real biology doesn’t work anything like that. Making one mutation in one of my genes will on average make it worse, though sometimes not. If it produces a protein, a single amino acid change often leaves the protein still functioning. But making changes in every site of its DNA is the same as replacing every protein by a random string of amino acids. Which will be a complete disaster.

Similarly, in statements in English, one typographical error might change “to be or not to be that is the question” into “to be or not to de that is the question”. Changing all letters would give something like “bdglvwujzib lxmoxg rjdg a ohlowugrbl owj”. It should be obvious that the latter is far less functional. The comprehensibility of English sentences is more like the actual fitness of organisms, and not like the fitness of the organisms Dembski and Marks imagine.

So, basically, by building a model in which the accumulation of mutations to improve fitness is impossible, they proved that the accumulation of mutations to improve fitness is impossible. What a stunning accomplishment!

Before creationists leap in an argue that he's not a biologist, he's a mathematician, and he's carrying out an analysis of the underlying mathematics of evolution, he's not even competent at that. One point mentioned in the talk is Dawkins' "Weasel" model of how selection can lead to refinement of a sequence. It's a very simple, fundamentally inarguable demonstration of how selection can work, and yet, for years Dembski & Co. have gotten it completely wrong, been unable to puzzle out exactly how it works, and have distorted both its purpose and its algorithm. He's still getting it wrong.

One should note in passing Dembski’s use of Richard Dawkins’s “Methinks It Is a Weasel” model. In his Chicago talk, Dembski portrays Dawkins as arguing that the Weasel model shows that natural selection can originate information, and portrays Dawkins as claiming that it is a realistic model of evolution. Dawkins was not arguing that it was a realistic model of evolution, or that this evolution originated new information. Dawkins’s model was a teaching example to show why creationist debaters who argue that natural selection is doing a “random” search are disingenuous. The Weasel search succeeds in about 1000 steps, while a truly random search would take astronomical numbers of steps. Dawkins’s model is an effective teaching device. It is routinely misrepresented in the creationist and ID literature as intended to be a realistic model of evolution, and intended to prove assertions about where the information in life originates. Unfortunately Dembski has followed this sad tradition.

You know, when you can't puzzle out a simple BASIC program written by a biologist, I don't think you have any credibility in your assertion that your vast logic and math skills have sussed out all of biology and evolution.