Ken Miller has now published his review of Behe’s latest. He did an excellent job. I think he really nailed some of Behe’s more egregious mathematical errors:
Behe, incredibly, thinks he has determined the odds of a mutation “of the same complexity” occurring in the human line. He hasn’t. What he has actually done is to determine the odds of these two exact mutations occurring simultaneously at precisely the same position in exactly the same gene in a single individual. He then leads his unsuspecting readers to believe that this spurious calculation is a hard and fast statistical barrier to the accumulation of enough variation to drive darwinian evolution.
It would be difficult to imagine a more breathtaking abuse of statistical genetics.
Behe obtains his probabilities by considering each mutation as an independent event, ruling out any role for cumulative selection, and requiring evolution to achieve an exact, predetermined result. Not only are each of these conditions unrealistic, but they do not apply even in the case of his chosen example. First, he overlooks the existence of chloroquine-resistant strains of malaria lacking one of the mutations he claims to be essential (at position 220). This matters, because it shows that there are several mutational routes to effective drug resistance. Second, and more importantly, Behe waves away evidence suggesting that chloroquine resistance may be the result of sequential, not simultaneous, mutations (Science 298, 74-75; 2002), boosted by the so-called ARMD (accelerated resistance to multiple drugs) phenotype, which is itself drug induced.
Behe’s casual use of probability was something that really struck me about the book. The probability of obtaining enough favorable mutations to drive significant evolutionary change depends on so many variables that no simple calculation could possibly encompass enough of them to be meaningful. Using specific examples such as malaria to derive sweeping general conclusions about what evolution can and can not do is rather dubious logic, to say the least. The fact is we have ample indirect evidence that complex systems are the result of the gradual accretion of random variations. If a particular mathematical model says that such a thing is not possible, it is almost certainly the mathematics that must yield.