Over at Pharyngula, PZ points to an interview with former Arkansas Governor and presidential hopeful Mike Huckabee. As a Canadian, I have long been amused by Huckabee for reasons you can see here. The prospect of this guy becoming president is unnerving, but then so is the fact that our neighbours saw fit to elect (or at least, not not-elect) Bush. Twice.

Here is what Huckabee has to say about evolution. I have omitted the bit about teaching non-scientific alternatives in science class that preceded it, because it’s too silly to repeat (he says “all views”, but presumably he means “one other view” only).

Because, frankly, Darwinism is not an established scientific fact. It is a theory of evolution, that’s why it’s called the theory of evolution.

He’s right. “Darwinism” — a term used mostly by creationists, but also historically (e.g., Wallace) and to an extent today (e.g., Dawkins), especially in Britain — refers to natural selection as a mechanism of evolution. And it is a theory. In science, a theory is an explanation for an observed or inferred condition of the natural world that is well established through multiple lines of empirical evidence (i.e., a fact). Darwin’s theory of natural selection is one explanation for the fact that species are related through descent, which in turn has been well established in science for well over a century on the basis of fossils, biogeography, embryology, morphology, and genetics. Darwinian natural selection is not the only available explanation, and therefore represents a subset of modern evolutionary theory. That natural selection happens is an established fact (witness antibiotic resistance), but what its role is in causing large-scale evolution remains a subject of discussion among biologists.

So “Darwinism,” in the sense of meaning that the majority of evolution occurs via natural selection, is indeed not an established fact, it is a theory. Huckabee’s words are correct, even if his intent is terribly muddled. Scientific theories explain facts. If there is no established fact, then there is no theory needed.

I invite Gov. Huckabee to read more about this in a recent paper that is freely available here.