Spatiotemporal modes of speciation

In this work we unveil the key structure of models for speciation driven by density and frequency dependent fitness. Starting from individual based models (IBM) in genotype space we gradually reduce the model complexity to finally two dynamical variables for (i) the degree of bimodality of the phenotype distribution in the population and (ii) of assortativity in mate choice. In this framework sympatric speciation appears as a simple bifurcation and can be treated analytically. Extensions of the model to (a) asymmetric phenotype distributions, (b) different mate choice criteria, and (c) spatially heterogeneous population distributions (including parapatry) are straightforward and briefly discussed.