Evolutionary food web model based on body masses gives realistic networks with permanent species turnover

TL;DR

This paper presents an eco-evolutionary food web model based on body masses that produces realistic, stable networks with ongoing species turnover, closely resembling natural ecological systems.

Contribution

It introduces a biologically meaningful trait-based model where species evolve through modifications of body mass and prey preferences, resulting in realistic food web structures.

Findings

Networks show high similarity to natural food webs

Continuous species turnover observed without massive extinctions

Model captures complex stability of ecological systems

Abstract

The networks of predator-prey interactions in ecological systems are remarkably complex, but nevertheless surprisingly stable in terms of long term persistence of the system as a whole. In order to understand the mechanism driving the complexity and stability of such food webs, we developed an eco-evolutionary model in which new species emerge as modifications of existing ones and dynamic ecological interactions determine which species are viable. The food-web structure thereby emerges from the dynamical interplay between speciation and trophic interactions. The proposed model is less abstract than earlier evolutionary food web models in the sense that all three evolving traits have a clear biological meaning, namely the average body mass of the individuals, the preferred prey body mass, and the width of their potential prey body mass spectrum. We observed networks with a wide range of sizes and structures and high similarity to natural food webs. The model networks exhibit a continuous species turnover, but massive extinction waves that affect more than $50 \%$ of the network are not observed.