Eco-evolutionary dynamics in finite network-structured populations with migration

TL;DR

This paper investigates how network structure influences eco-evolutionary dynamics, considering population size, distribution, and migration behaviors, revealing that network topology affects mutant success depending on migration rates.

Contribution

It introduces a model that explicitly accounts for changing population size and distribution in network-structured populations with migration influenced by competition tolerance.

Findings

Complete and cycle networks show similar mutant success at low/high migration rates.

High migration in star networks reduces mutant success due to crowding at the central site.

Population distribution dynamics significantly impact mutant appearance and success.

Abstract

We consider the effect of network structure on the evolution of a population. Models of this kind typically consider a population of fixed size and distribution. Here we consider eco-evolutionary dynamics where population size and distribution can change through birth, death and migration, all of which are separate processes. This allows complex interaction and migration behaviours that are dependent on competition. For migration, we assume that the response of individuals to competition is governed by tolerance to their group members, such that less tolerant individuals are more likely to move away due to competition. We looked at the success of a mutant in the rare mutation limit for the complete, cycle and star networks. Unlike models with fixed population size and distribution, the distribution of the individuals per site is explicitly modelled by considering the dynamics of the population. This in turn determines the mutant appearance distribution for each network. Where a mutant appears impacts its success as it determines the competition it faces. For low and high migration rates the complete and cycle networks have similar mutant appearance distributions resulting in similar success levels for an invading mutant. A higher migration rate in the star network is detrimental for mutant success because migration results in a crowded central site where a mutant is more likely to appear.