Fixation in competing populations: Diffusion and strategies for survival

Abstract

How should dispersal strategies be chosen to increase the likelihood of survival of a species? We obtain the answer for the spatially extended versions of three well-known models of two competing species with unequal diffusivities. Though identical at the mean-field level, the three models exhibit drastically different behavior leading to different optimal strategies for survival, with or without a selective advantage for one species. With conserved total particle number, dispersal has no effect on survival probability. With a fluctuating number, faster dispersal is advantageous if intraspecies competition is present, while moving slower is the optimal strategy for the disadvantaged species if there is no intraspecies competition: it is imperative to include fluctuations to properly formulate survival strategies.

Coalescent dynamics of planktonic communities

“…IBMs have also been used to study microbial planktonic communities [10][11][12][13][14]. These models have been used to predict, for example, how fluid flows affect the fate of mutants characterized by a reproductive advantage [13][14][15][16][17] or by a different diffusivity [18][19][20][21]. However, when used to predict biodiversity patterns, these models face severe computational limitations.…”