Respect for males amid suppression of females: Selective use of aggression and fitness correlates in the male-dominated society of hamadryas baboons.

Hamadryas baboons (Papio hamadryas) are a useful model for human social evolution for multiple reasons, including their multilevel society, intense cross-sex bonds, and intermale tolerance. Their most stable social grouping, the one-male unit (OMU)-comprising a leader male, females, and sometimes follower males-is formed via successive takeovers of individual females by males. While takeovers occur via both aggressive and non-aggressive mechanisms, aggressive herding is common during and after takeovers and appears crucial in maintaining OMUs.