Slow evolution towards generalism in a model of variable dietary range

TL;DR

This paper models how species evolve their dietary ranges in shared habitats, revealing slow, path-dependent dynamics that tend to favor generalist diets due to stochastic effects and long-lived quasi-stable states.

Contribution

It introduces a mathematical model of niche formation showing how stochastic effects influence the evolution towards generalism in dietary ranges.

Findings

Long-lived quasi-stable states in dietary evolution

Stochastic effects drive the shift towards generalist diets

Evolutionary dynamics are highly path-dependent

Abstract

Species sharing a habitat will co-evolve to make use of the available resources, as consumption is modulated by competition and negative feedback loops between consumers and resources. The dietary range of a given species determines the resources it has access to and thus the other species with which it competes. A narrow dietary range avoids competition at the cost of over-reliance on a small selection of resources; conversely a wide dietary range provides more alternatives but also more chance of competition with other species. Here, we investigate the evolution of dietary range within a mathematical model of niche formation. We find highly path dependent co-evolution dynamics characterised by long-lived quasi-stable states. Ultimately, stochastic effects drive the evolution of generalist diets, as we uncover in our analysis and simulations.