The Unified Neutral Theory of Biodiversity and Biogeography

Study of the issue indicates that it is not a serious problem for neutral theory, for reasons we discuss below. First, a bit of background. Hubbell (2001) derived the analytical expression for the stochastic mean and variance of the abundance of a single arbitrary species in a neutral community undergoing immigration from a metacommunity source area. However, his approach did not lend itself to an analytical solution for the distribution of relative species abundance (RSA) in a multispecies community for community sizes larger than a handful of individuals. As a result, all of Hubbell's RSA distributions for local communities were based on simulations. This problem was solved by Volkov et al. (2003), who…