Courant Research Centre Evolution of Social Behaviour, University of Göttingen (Germany), Centre for Ecology and Conservation, University of Exeter (UK)
Friday 10:45-11:00, Ballroom A
Conflict over reproduction is a fundamental problem of social evolution since it may impede the stability of social groups of animals. A multitude of theoretical studies have thus addressed this problem, a prominent class of models being so-called tug-of-war models. These models assume that natural selection may resolve reproductive conflict among group members owing to the negative impact of such conflict on the contestants’ fecundity. Reproductive conflict among primate males is often intense, and many researchers have concluded that the observed patterns of conflict are well described by tug-of-war models. Here, I argue that this conclusion is wrong. Tug-of-war models have been originally developed to address reproductive conflict among females. In their present form, however, they are not suitable to describe reproductive conflict among males (in primates as well as in other vertebrates), because the proposed tradeoff between reproductive effort and fecundity is far less important in males than in females. I show, however, how the models can be modified to address the tradeoff between reproductive effort and survival, which is deemed to be a more important determinant of fitness in males. Based on my current work, I further show how this approach can be used to also study the resolution of conflict over group membership. In summary, I highlight a common misconception in the application of tug-of-war models and outline a theory which is more suitable than current models to study reproductive conflict among male primates.
This work was supported by the German VolkswagenStiftung (Volkswagen Foundation).