Effects of niche overlap on co-existence, fixation and invasion in a population of two interacting species

TL;DR

This paper explores how the degree of niche overlap influences the stability, coexistence, and fixation dynamics of two interacting species, with implications for ecological and microbiological systems.

Contribution

It introduces a model analyzing the transition from stable coexistence to fixation driven by niche overlap and examines invasion stability in such populations.

Findings

Higher niche overlap leads to increased fixation events.

Lower niche overlap promotes stable coexistence.

Niche overlap significantly affects invasion resistance.

Abstract

Synergistic and antagonistic interactions in multi-species populations - such as resource sharing and competition - result in remarkably diverse behaviors in populations of interacting cells, such as in soil or human microbiomes, or clonal competition in cancer. The degree of inter- and intra-specific interaction can often be quantified through the notion of an ecological "niche". Typically, weakly interacting species that occupy largely distinct niches result in stable mixed populations, while strong interactions and competition for the same niche results in rapid extinctions of some species and fixations of others. We investigate the transition of a deterministically stable mixed population to a stochasticity-induced fixation as a function of the niche overlap between the two species. We also investigate the effect of the niche overlap on the population stability with respect to external invasions. Our results have important implications for a number of experimental systems.