GELIFES Seminars - Peter Kappeler

Peter Kappeler (Universität Göttingen & Deutsches Primatenzentrum)

The evolution of sex roles in primates

In virtually all sexually reproducing species, males and females differ in the degree of within-sex reproductive competition, how discriminating individuals are during pair formation and the extent to which they exhibit parental care after mating. These sex roles have been thought to be related to how much males and females invest in gamete production, but recent research has indicated that a species’ life history and the ratio of males and females in a population – the adult sex ratio (ASR) – are more important determinants of interspecific variation in sex roles. In this talk, I will therefore examine the relationships between inter- and intra-specific variation in sex roles and ASR in the mammalian order for which the most detailed behavioral data exist: the non-human primates. The primates of Madagascar (lemurs) play a special role in this context, because they evolved unusual components of sex roles independently of other primates. Important general conclusions of this discussion include the fact that sex roles and ASR are more intimately related than previously thought and that lineage-specific life history traits can have important effects on the evolution of sex roles.