  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.
