Wednesday, April 19, 2006

No Free Lunch Again

Shortly after William Dembski unleashed No Free Lunch on the world, H. Allen Orr, biology professor at the University of Rochester, wrote an inciteful review of the work. In it, he notes Dembski's principle objection to evolutionary mechanics, that they are incapable of generating specified complexity. No evolutionary outcome would be any better than any other. Only a designer could make an eye or a flagella--Darwinism cannot. This is a fundamental misunderstanding of how evolution works. As Orr puts it:

The problem with all this is so simple that I hate to bring it up. But here goes: Darwinism isn't trying to reach a prespecified target. Darwinism, I regret to report, is sheer cold demographics. Darwinism says that my sequence has more kids than your sequence and so my sequence gets common and yours gets rare. If there's another sequence out there that has more kids than mine, it'll displace me. But there's no pre-set target in this game.

He also notes another problem with Dembski's interpretation: the lack of consideration of deep time.

But now change the environment. This shifts the landscape's topography: a sequence's fitness isn't cast in stone but depends on the environment it finds itself in. Each population may now find it's no longer at the best sequence and so can evolve somewhat even if the new landscape is still rugged. Different populations will go to different sequences as they live in different environments. Now repeat this for 3.5 billion years. Will this process yield interesting products? Will we get different looking beasts, living different kinds of lives? My guess is yes. Dembski's is no. And that is, I suppose, fine. He's entitled to his guess. But don't let him tell you that it follows ineluctably from some mathematical theorem because it doesn't.

Orr also notes the logical fallacy in the concept of irreducible complexity:

Some part (A) initially does some job (and not very well, perhaps). Another part (B) later gets added because it helps A. This new part isn't essential, it merely improves things. But later on, A (or something else) may change in such a way that B now becomes indispensable. This process continues as further parts get folded into the system. And at the end of the day, many parts may all be required.

It is a good article, full of answers to questions that very few people want to ask about the logic of the current ID focus. Read the whole thing.

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