Behavioural evidence on the evolution of batesian mimicry

Abstract

1.1. Four White Leghorn chicks were trained to avoid a drawing of a butterfly (the model) and than presented with various other butterfly drawings (the mimics).2.2. Some mimics resembling the model only slightly were avoided.3.3. Some of the literature indicating that animals usually respond to only a portion of the visual environment that they are capable of seeing is summarised.4.4. On the basis of the experiment and the literature, it is concluded that behavioural studies provide no evidence for and considerable evidence against the Saltation theory and tend to support the Neo-Darwinian theory of the origin of mimicry.5.5. Some possible explanations for the complexity of a model warning coloration and the completeness of a mimetic resemblance are discussed.6.6. It is suggested that the original resemblance acquired by an incipient mimic is a simple, generalised conspicuousness such as a large area of red or black. This would then be improved by selection of further mutations. The evolution of a more-or-less complete resemblance from the original generalised one may take place very rapidly.7.7. The possible importance of preadaptation in the origin of mimicry is suggested.8.8. The possibility that in some cases the new incipient resemblance may interfere with releasers involved in breeding behaviour is briefly discussed.