Evolution of polymorphism and sympatric speciation through competition in a unimodal distribution of resources

A microscopic agent dynamical model for diploid age-structured populations is used to study evolution of polymorphism and sympatric speciation. The underlying ecology is represented by a unimodal distribution of resources of some width. Competition among individuals is also described by a similar distribution, and its strength is maximum for individuals with the same phenotype and decreases with distance in phenotype space as a gaussian, with some width. These two widths define the model's phase space, in which we identify the regions where an autonomous emergence of stable polymorphism or speciation is more likely.