Abstract

While prior models of the evolution of altruism have assumed that organisms reproduce asexually, this paper presents a model of the evolution of altruism for sexually reproducing organisms using Hardy–Weinberg dynamics. In this model, the presence of reciprocal altruists allows the population to evolve to a stable polymorphic population where the majority of organisms are altruistic. Further, adding stochasticity leads to even larger numbers of altruists, while adding stochasticity to an analogous asexual model leads to more selfish organisms. The contrast between these outcomes demonstrates why it may be important to pay attention to the underlying genetics of a population