The Rapid Origin of Reproductive Isolation

摘要

The part that natural selection plays in the origin of species has long been debated. It is easy to see that if two populations are kept separate—by mountains or ocean, for example—they will eventually become so different that they can no longer interbreed successfully. Their differences may have evolved by natural selection, but their reproductive isolation is merely a side effect of changes that emerged for other reasons. This view seems unsatisfactory to those who emphasize the positive aspect of selection in evolution. Both Alfred Russell Wallace and Theodosius Dobzhansky argued that natural selection would reinforce reproductive barriers between diverging populations.