Evolution of Mate-choice Copying Adapted to Environmental Changes

Abstract

Nonindependent mate choice occurs when a female is influenced in her choice of a mate by her social environment. Mate-choice copying (MCC) is a typical example of nonindependent mate choice wherein mating decisions are influenced by observing the mating preferences of other individuals of the same species. It is an inheritable trait, and copiers and noncopiers exist in the same species. This means that MCC has both advantages and disadvantages. Furthermore, the advantages of MCC are confirmed, but the disadvantages are not. For this reason, we clarified the disadvantages of MCC and considered the nature of MCC. Since MCC causes the synchronization of mating preferences in a species, the diversity of the species decreases. Therefore, we used scenarios of different environmental changes to examine the disadvantages of MCC. In this work, we simulated MCC behavior using an agent-based model consisting of the imported MCC gene and female preferences influenced by the mate choices of other individuals as a meme. Only those agents with the MCC gene could imitate the mate choice of other females, and imitation of mate choice implied that a female imitates the gene trait of a male who is the most popular with her preference meme in our proposed model. We reproduced environmental changes in this model and explored the disadvantages of MCC. Experimental results revealed a disadvantage of MCC, and we discuss the trigger of MCC focusing on the experimental environment.