The Evolution of Aposematic Coloration by Individual Selection: A Life-Span Survival Model

Abstract

Distasteful prey are often conspicuously coloured, i.e. aposematic. As aposematic coloration entails a higher probability that the prey is discovered by a predator, kin selection has been thought to be a prerequisite for the evolution of aposematic coloration. However, by using a life-span survival model we here demonstrate how a gene for aposematic coloration can invade, and spread, in a population of cryptic distasteful prey by means of individual selection. Our model is based on the recent finding that seizing a prey gives a predator information about its distastefulness, thus conferring a higher probability of survival by being released unharmed for distasteful prey, and that predators learn to avoid conspicuously coloured prey more readily than they do cryptic prey. From our model we can predict that the evolution of aposematic coloration will be favoured in prey with long pre-reproductive phases, a high degree of distastefulness, and occupying habitats with small possibilities for hiding from predators.