The standard simplified narrative of evolutionary adaptation goes something like this. A population of organisms is exposed to a challenge of some kind. Perhaps a new predator has appeared on the scene, or the temperature of the environment has ticked up a degree or two, or the warm little pond is slowly accumulating a toxic chemical.

In a previous post, I started to explain a fact that some people (who don't know me) seem to find surprising or noteworthy. Michael Behe is a Christian who accepts common ancestry and an ancient cosmos, so you'd think I would be excited about the work of a fellow "theistic evolutionist." But I'm not. Two overall problems come to mind.

Several weeks ago, a commenter (Donald) asked an interesting question about natural selection and genetic variation, and I promised to address it because I want the issue to be a theme on QoD in the coming months. Here's Donald: The blog article that Donald is citing is at The Wild Side by Olivia Judson, and the figure of 100,000 deleterious mutants for every helpful one is widely referenced.