Intra- and Intersexual Conflicts and Cooperation in the Evolution of Mating Strategies: Lessons Learnt From Ungulates

The traditional narrow focus on male mate competition in studies of mammalian mating strategies has been successful in explaining many conspicuous outcomes of sexual selection. However, focusing on ungulates, I here review increasing evidence that a comprehensive understanding of sexually selected adaptations requires consideration of a broader range of sex roles, particularly those relating to female behaviour. I show how mate competition and mate choice in both sexes can interact and often lead to intra- and intersexual conflicts and sometimes also cooperation. By causing phenotypic selection, these behavioural interactions can shape evolution although the outcome depends on genetic constraints. I conclude that to advance the understanding of mammalian mating systems we must broaden our conceptual framework from being largely focused on male competitive strategies to encompass coevolutionary dynamics between the mating strategies of both sexes. Future challenges include clarifying (1) the ecological basis for the inter- and intraspecific diversity in sex roles, (2) the condition-dependence of female mating strategies, and (3) the ultimate causes of mate competition and promiscuity in females.