Speaker: Dr. Yi-Zhi Pang
Title: Allee effects in finite size population: percolation transition and flow effects
Abstract: Allee effects are broadly defined as a decline in individual fitness at low population size or density,
that can result in critical population thresholds below which populations crash to extinction. However, the population dynamics, subject to both the Allee effects and stochastic perturbations induced by finite size population, remains an unexplored challenge, both theoretically and experimentally. In this seminar, we employ an individual-based model to investigate the survival probability of a finite population with Allee effects. Firstly, we focus on the survival probability of one population in the well mixed case, and find that there is a critical value of Allee effects under fluctuations. Next, by extending to one dimensional, we reveal that direct percolation transition is exhibited across the critical line with respect to Allee effects and diffusivity. Finally, in two dimensional, our results show a limited range for diffusivity, as well as the critical velocity in
incompressible advective fields. These findings may have important implications in the understanding of the population dynamics, such as bacteria in marine environments. Further research into the two populations is required.
