Abstract
We study competition between two biological species advected by a compressible velocity field. Individuals are treated as discrete Lagrangian particles that reproduce or die in a density-dependent fashion. In the absence of a velocity field and fitness advantage, number fluctuations lead to a coarsening dynamics typical of the stochastic Fisher equation. We investigate three examples of compressible advecting fields: a shell model of turbulence, a sinusoidal velocity field and a linear velocity sink. In all cases, advection leads to a striking drop in the fixation time, as well as a large reduction in the global carrying capacity. We find localization on convergence zones, and very rapid extinction compared to well-mixed populations. For a linear velocity sink, one finds a bimodal distribution of fixation times. The long-lived states in this case are demixed configurations with a single interface, whose location depends on the fitness advantage.
| Originalsprog | Engelsk |
|---|---|
| Tidsskrift | Physical Review Letters |
| Vol/bind | 108 |
| Udgave nummer | 12 |
| Sider (fra-til) | 128102 |
| Antal sider | 5 |
| ISSN | 0031-9007 |
| DOI | |
| Status | Udgivet - 23 mar. 2012 |