Earlier attempts to show that simpler theories always have higher prior probabilities have failed, but there is a restricted circumstance in which the claim is right.

When one theory is simpler than its competitor, this fact is relevant to saying what the world is like.

Trait X is fitter than trait Y in a population of organisms if those organisms have other biological traits T and live in an environment that has properties E. The theory of natural selection is filled with statements of this form.

If the organisms in a species now have trait T, and this trait now helps those organisms to survive and reproduce because the trait has effect E, a natural hypothesis to consider is that T evolved in the lineage leading to those current organisms because T had effect E. This hypothesis is "natural," but it often isn't true!

Instead of thinking of the question of race genealogically, and leaving it open whether vernacular races are genealogical units, the interest in biomedicine has been to determine whether vernacular racial categories are medically useful in diagnosis and treatment. There is on-going debate about this.

I think that some "interventionist theisms" are compatible with evolutionary theory. (By "intervention," I don't mean that God violates laws of nature; I mean that God affects what happens in nature in ways that are additional to the ones that deism recognizes.)

I don't endorse deism or interventionist theism. My point is just that evolutionary biology is logically compatible with the former and with some versions of the latter.