Evolution of Colour Vision

Abstract

A DISCUSSION of the evolution of colour vision took place at the general meeting of the Linnsæn Society on February 24. Dr. R. J. Pumphrey, while disclaiming expert knowledge, said that it seemed fitting that a zoologist should have been invited to open the discussion rather than a specialist in human colour vision, however knowledgeable, since a zoological training enforces a historical outlook, which is essential for the ultimate understanding of the evolution of function. The evidence available from animals other than mammals, though extremely relevant, is still scanty ; inferences from structure and physiology cannot be relied on. Colour vision can only be ascribed to an animal when the intact animal, either in the field or in a controlled experimental situation, has been shown to exercise a choice depending on colour discrimination. Such a test is always a matter of extreme technical difficulty, and is not applicable to any animal without restriction but only to those whose habits and motivation make them suitable subjects. In spite of these limitations, colour vision has been demonstrated beyond reasonable doubt in a number of insects, notably aculeate Hymenoptera, Diptera and Lepidoptera, and a number of vertebrates, notably teleost fish, reptiles, birds and primates.