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.

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

Darwin and his successors have railed against the fallacy of confusing the current utility of a trait with the reason the trait evolved. For example, Darwin argued that skull sutures in mammals did not evolve because they facilitate live birth; the sutures were in place well before live birth evolved. Checking the chronological order in which different traits evolved in a lineage is one way to test an adaptive hypothesis; the fact of common ancestry is what makes that checking possible.

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.

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.

Scientists often seek predictively accurate models, rather than models that are true.

Evolutionary biologists often appeal to parsimony when they seek to explain why organisms "match" with respect to a given trait. For example, why do almost all the organisms that are alive today on our planet use the same genetic code? If they share a common ancestor, the code could have evolved just once and then been inherited from the most recent common ancestor that present organisms share. On the other hand, if organisms in different species share no common ancestors, the code must have evolved repeatedly.