Our own species evolved under the influence of group selection, as Darwin emphasized when he discussed the evolution of altruism.

The big picture, I think, is that common ancestry is evidentially prior to natural selection in Darwin's theory and in contemporary evolutionary biology as well.

The racial categories that are used in a given society (for example, in contemporary America) are biologically meaningless, but sometimes it turns out that a vernacular racial category has biological reality.

Current organisms have a higher probability of sharing a single code if the common ancestry hypothesis is true than they'd have if the hypothesis of separate ancestry were true. That is, the simpler hypothesis has the higher likelihood in the technical sense of "likelihood" used in statistics.

"Tiger is a natural kind" and "Tiger is a historical particular" are incompatible with each other, and evolutionary biology provides a reason for favoring the latter over the former.

In the history and literature courses I took, epistemological questions came to interest me most. What makes one explanation of the French Revolution better than another? What makes one interpretation of "Waiting for Godot" better than another? These questions led me to philosophy and then to philosophy of science.

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