Assortative Mating: Encounter-Network Topology and the Evolution of Attractiveness

Abstract: We model a social-encounter network where linked nodes match for reproduction in a manner depending probabilistically on each nodes attractiveness. The developed model reveals that increasing either the networks mean degree or the choosiness exercised during pair-formation increases the strength of positive assortative mating. That is, we note that attractiveness is correlated among mated nodes. Their total number also increases with mean degree and selectivity during pair-formation. By iterating over model mapping of parents onto offspring across generations, we study the evolution of attractiveness. Selection mediated by exclusion from reproduction increases mean attractiveness, but is rapidly balanced by skew in the offspring distribution of highly attractive mated pairs.