This is a first-hand account of the discussions that are going on between biologists of different persuasions. On the one side are the Ultra-Darwinists - mainly theoretical geneticists - whose ranks include Richard Dawkins, John Maynard Smith and George C. Williams. They emphasize the supremacy of the gene and of natural selection. The other side is a more diverse group, the self-styled Naturalists, who focus on whole creatures rather than genes and who think in terms of complex interacting ecological processes; here we find Stephen Jay Gould and Niles Eldredge.