Neutral dynamics with environmental noise: age-size statistics and species lifetimes

Abstract

Neutral dynamics, where taxa are assumed to be demographically equivalent and their abundance is governed solely by the stochasticity of the underlying birth-death process, has proved itself as an important minimal model that accounts for many empirical datasets in genetics and ecology. However, the restriction of the model to demographic [$\mathcal{O}(\sqrt{N})$] noise yields relatively slow dynamics that appears to be in conflict with both short-term and long-term characteristics of the observed systems. Here we analyze two of these problems - age size relationships and species extinction time - in the framework of a neutral theory with both demographic and environmental stochasticity. It turns out that environmentally induced variations of the demographic rates control the long-term dynamics and modify dramatically the predictions of the neutral theory with demographic noise only, yielding much better agreement with empirical data. We consider two prototypes of "zero mean" environmental noise, one which is balanced with regard to the arithmetic abundance, another balanced in the logarithmic (fitness) space, study their species lifetime statistics and discuss their relevance to realistic models of community dynamics.

References in corpus (4)

• Neutral Theory and Relative Species Abundance in Ecology
• Spatial effects on species persistence and implications for biodiversity
• Species lifetime distribution for simple models of ecologies
• Prescription-induced jump distributions in multiplicative Poisson processes

Cited by in corpus (6)

• Statistical Mechanics of Ecological Systems: Neutral Theory and Beyond
• Species coexistence in a neutral dynamics with environmental noise
• Chaotic turnover of rare and abundant species in a strongly interacting model community
• Theory of time-averaged neutral dynamics with environmental stochasticity
• A comprehensive phase diagram for logistic populations in fluctuating environment
• Success probability for selectively neutral invading species in the line model with a random fitness landscape