Sympatric speciation through assortativity: the role of neutral and mating trairs

Abstract

Understanding the processes that lead to the formation of species has been a widely explored topic in evolutionary biology and ecology. Several deterministic and stochastic models have been developed to study the emergence of species from a single population. One of the most simple and elegant models is that proposed by Derrida and Higgs, which presents an approach to neutral speciation in a sympatric framework. In this model, speciation relies on how individuals choose their mating partners. Thus, the core of the speciation process isa rule that constraints possible mating partners to a subset defined by a maximum genetic distance between the parents. The genetic distance is computed using the entire genome of the individuals. Here we explore a variation of the model which is more consistent with natural systems. Instead of constraining the partners to mate according to the genetic distances of their entire genomes, we propose the evaluation of only finite segments corresponding to specific mating traits. This allows the partners to focus only on information that could be relevant to mate depending on their nature. Genes corresponding to other, neutral or ecological traits, however, also recombine during mating and will influence the resulting species. One of the goals of this study is to understand and quantify the distribution of both mating and neutral traits in the population Moreover, this study allows us to explore the role of assortative mating for species formation and on the hybridization process. (AU)