Group selection and individual selection are just two of the selection processes that have played important roles in evolution. There also is selection within individual organisms (intragenomic conflict), and selection among multi-species communities (an idea that now is getting attention in work on the human microbiome). All four of these levels of selection find a place in multi-level selection theory.

Methodological naturalism gives advice to scientists about what they should include in their theories. There is a second type of methodological naturalism that gives advice to philosophers, which I call "methodological naturalismp." It says that the methods that philosophers should use in assessing philosophical theories are limited to the methods that scientists ought to use in assessing scientific theories.

Some philosophical arguments (e.g., in connection with the mind/body problem) look pretty good, while others (e.g., those that criticize moral realism) do not.

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!

From the fact that E is evidence for T and the fact that T entails M, it doesn't follow that E is evidence for M.

Darwin repeatedly used the hypothesis of common ancestry as a platform on which to build his various ideas about testing hypotheses concerning natural selection. He also argued that adaptive similarities provide little or no evidence for common ancestry. Although this second claim needs to be fine-tuned, Darwin was right that ample evidence for common ancestry can exist even if none of the characteristics we observe were caused to evolve by natural selection.

"Methodological naturalism" and "metaphysical naturalism" are terms that often surface in the continuing battle between evolutionary biology and creationism/intelligent design. The methodological thesis says that scientific theories shouldn't postulate supernatural entities; the metaphysical thesis says that no such entities exist. In this debate, God is the supernatural entity at issue; the question isn't whether science gets to talk about mathematical entities if Platonism is correct.