Arthur Cain and ecological genetics in the Oxford Zoology Department

In the two decades after the Second World War a group of members of the University of Oxford’s Zoology Department investigated evidence for and the strength of natural selection in wild populations, a subject that had been developing since the beginning of the century. They provided a stimulus for many further field studies by others and in other places. Their central contention was that strong selection led to the close adaptation of all aspects of the genome of organisms to their environment. The research centred on the work of E. B. Ford and H. B. D. Kettlewell, on the one hand, and A. J. Cain, on the other. Ford was influenced by R. A. Fisher’s theory of the evolution of dominance, which he maintained led to heterozygote advantage, polymorphism and thus high levels of genetic diversity. While convinced of the power of selection and studying a conspicuous polymorphism, Cain had a much broader interest in adaptation and speciation