I’ve written before about the interesting symbiosis that exists between militant atheism and religious fundamentalism — the way the Richard Dawkinses of the world are always eager to insist that a cartoonish figure like Pat Robertson represents the truest form of Christian faith, and that any believer who disagrees with Robertson’s pronouncements on Haiti or Hurricane Katrina obviously doesn’t understand his own religion.

For a recent example of this tendency, consider the fascinating exchange between the prolific Catholic blogger Mark Shea and Jerry Coyne, the author of “Why Evolution Is True” and a Dawkins-esque critic of biblical religion. The subject is human origins, and specifically the debate over whether the Western Christian understanding of original sin — as the fruit of a primal disobedience by the human’s race first family — is compatible with the increasing scientific consensus around polygenism (that is, the theory that today’s human race descends from a larger population rather than a single couple).