6533b7dbfe1ef96bd12715b6

RESEARCH PRODUCT

Strong Noise Effects in one-dimensional Neutral Populations

Luca Dall'astaFabio CaccioliDeborah Begh��

subject

Statistical Mechanics (cond-mat.stat-mech)FOS: Biological sciencesPopulations and Evolution (q-bio.PE)FOS: Physical sciencesQuantitative Biology - Populations and EvolutionCondensed Matter - Statistical Mechanics

description

The dynamics of well-mixed biological populations is usually studied by mean-field methods and weak-noise expansions. Similar methods have been applied also in spatially extended problems, relying on the fact that these populations are organized in colonies with a large local density of individuals. We provide a counterexample discussing a one-dimensional neutral population with negative frequency-dependent selection. The system exhibits a continuous phase transition between genetic fixation and coexistence unexpected from weak-noise arguments. We show that the behavior is a non-perturbative effect of the internal noise that is amplified by presence of spatial correlations (strong-noise regime).

http://arxiv.org/abs/1012.1209