AVOIDING INBREEDING AND SIBLING COMPETITION - THE EVOLUTION OF SEXUAL DIMORPHISM FOR DISPERSAL

Natal dispersal can reduce sibling competition and the risk of inbreeding, but it may also confer a personal cost on the disperser. A simple gene-frequencies model is presented, which takes into consideration the effects of both competition and inbreeding avoidance on the evolution of dispersal. The evolutionarily stable strategies of dispersal are obtained, and the possibility of sexual dimorphism with regard to dispersal behavior is analyzed. If the cost of inbreeding is low, both sexes adopt the same dispersal strategy, whereas if the cost of inbreeding is high enough, we can expect to find sexual dimorphism with respect to dispersal behavior (even if both sexes have the same costs and benefits associated with dispersal).