Stochastic models for species formation in evolving populations

The authors introduce a simple model for sexual reproduction in a flat fitness landscape, the species formation model, which leads to a spontaneous division of a population into species. In this model mating between individuals is permitted only if their separation in genome space is less than a given value. This model shows non-self-averaging effects in the overlap distribution similar to what is observed in a one parent model representing asexual reproduction, and in contrast to a simpler model for sexual reproduction, the homogeneous population mode, in which random pairing of individuals is permitted.