The Evolution of Mimicry; a Problem in Ecology and Genetics

One of the early successes of the theory of natural selection concerned the phenomenon of mimicry. Bates (1862) noticed that in South America there are a number of simple and conspicuous color-patterns common to several distantly related species of Lepidoptera living together in the same habitat. He argued that in each of these assemblages there was at least one species (the model) which was distasteful to the predators of butterflies, and had a conspicuous color pattern which in general resembled that of other members of its genus. The other species (the mimics), he thought, were relatively edible and had evolved an appearance similar to that of the model as the result of natural selection; any slight variation causing the predators to mistake an insect for the model and therefore not to attack it, would confer an advantage on its possessor and therefore be favored.