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.
Elliott SoberThe rabid opposition to group selection has now considerably subsided. In the process, the conceptual structure of evolutionary theory has become clearer, as have the relationships that connect different theoretical approaches.
Elliott SoberI 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.
Elliott SoberDeism is logically compatible with evolutionary theory for the simple reason that the theory says nothing about the origin of the universe or of the laws of nature.
Elliott Sober"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.
Elliott SoberEvolutionary 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.
Elliott SoberI have spent a lot of time arguing that the theory of group selection is not the stupid, pernicious doctrine that many biologists once claimed it to be. The theory is not just conceptually coherent; there are adaptations out there in nature (like reduced virulence in some viruses) that evolved because there was group selection.
Elliott Sober