Mutations and Natural Selection

Abstract

This paper reviews the relations between mutations and natural selection in some of their modern aspects. It suggests that in mathematical theories of selection a distinction should be drawn between the whole species range and the effective interbreeding unit. Numerous cases of wild mutations and mutational varieties of plants are cited, and their relations to natural selection discussed. Other subjects considered are polyploids in relation to adaptation; parallel mutations in relation to phylogeny in plants, animals and man; the limits of parallelism. The common occurrence of parallel characters in every group from the Cyanophyceae to Angio-sperms and from Protozoa to man is emphasized.