Species abundance distribution in the finite genome Derrida-Higgs model

Abstract

Species Abundance Distributions (SAD) are important measures of diversity, allowing comparisons between communities even if they harbor different species. They typically show the presence of many of rare species and only a few common ones. Despite its importance in ecology, little is known about SADs resulting from de Derrida-Higgs model of species formation, a paradigm in the theory of sympatric speciation. Derrida and Higgs demonstrated that a sexually reproducing population can split into different species in the absence of natural selection or any type of geographic isolation, provided that mating is assortative and the number of genes involved in the process is infinite. For finite genomes, however, diversification can be completely stopped. Here we aim to study, numerically and analytically, the resulting SAD of the Derrida-Higgs dynamics and its relation with the genome size. The simulated SADs will also be used for comparisons with real datasets. (AU)