Sexual selection with a culturally transmitted mating preference

Abstract

Culturally transmitted mating preferences may generate sexual selection in human and protocultural animal species if they influence the intensity of selection on genetically transmitted physical and behavioral traits. Haploid and diploid two-"locus" models of sexual selection are presented in which mating preferences are culturally transmitted, while traits are transmitted genetically. The models exhibit dynamics similar to those of conventional haploid models of sexual selection, generating neutrally stable curves of equilibrium trait and preference frequencies. A culturally transmitted preference that reaches a significant frequency through cultural drift, individual learning, or social transmission can drag a less viable trait to fixation, or non-zero frequencies. Simulations suggest that strong biases in the transmission of preferences could take initially rare, less viable traits to fixation in as few as 20 to 50 generations, and weak biases in less than 100 generations. These conclusions hold for both biparental and maternally inherited mating preferences. Given the pervasiveness of cultural influences on human mate choice, the analysis suggests that this interaction may have played an important role in human evolution.