Global patterns of speciation and diversity

"A neutral theory (assuming no environmental selection or organismal interactions) has been shown to predict many patterns of ecological biodiversity^{2, 3}. This theory is based on a mechanism by which new species arise similarly to point mutations in a population without sexual reproduction. Here we report the simulation of populations with sexual reproduction, mutation and dispersal. We found simulated time dependence of speciation rates, species–area relationships and species abundance distributions consistent with the behaviours found in nature^{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13}. From our results, we predict steady speciation rates, more species in one-dimensional environments than two-dimensional environments, three scaling regimes of species–area relationships and lognormal distributions of species abundance with an excess of rare species and a tail that may be approximated by Fisher's logarithmic series (Nature)."