Prevalence of mutualism in a simple model of microbial co-evolution

TL;DR

This paper uses adaptive dynamics with a simple microbial model to demonstrate how ecological interactions can evolve, often leading to mutualism, highlighting the potential for ecological transitions driven by evolution.

Contribution

It introduces a simple two-microbial model combining adaptive dynamics and resource bookkeeping to explore ecological transitions, emphasizing the emergence of mutualism.

Findings

Model exhibits various ecological transitions including mutualism.

Evolutionary dynamics tend to favor the emergence of mutualism.

Simple model captures transitions similar to natural microbial interactions.

Abstract

Evolutionary transitions among ecological interactions are widely known, although their detailed dynamics remain absent for most population models. Adaptive dynamics has been used to illustrate how the parameters of population models might shift through evolution, but within an ecological regime. Here we use adaptive dynamics combined with a generalised logistic model of population dynamics to show that transitions of ecological interactions might appear as a consequence of evolution. To this purpose we introduce a two-microbial toy model in which population parameters are determined by a bookkeeping of resources taken from (and excreted to) the environment, as well as from the byproducts of the other species. Despite its simplicity, this model exhibits all kinds of potential ecological transitions, some of which resemble those found in nature. Overall, the model shows a clear trend toward the emergence of mutualism.