Rapid contemporary evolution and clonal food web dynamics

TL;DR

This paper investigates how rapid microevolution in clonal organisms influences freshwater plankton community dynamics, demonstrating that genetic differences within species can significantly alter ecological stability and species coexistence.

Contribution

It introduces models showing how within-species clonal variation impacts community stability and extends understanding of eco-evolutionary feedbacks in short-generation organisms.

Findings

Clonal differences in prey defense affect predator-prey stability.

Increased evolutionary potential can destabilize community dynamics.

Microevolutionary details influence species coexistence.

Abstract

Character evolution that affects ecological community interactions often occurs contemporaneously with temporal changes in population size, potentially altering the very nature of those dynamics. Such eco-evolutionary processes may be most readily explored in systems with short generations and simple genetics. Asexual and cyclically parthenogenetic organisms such as microalgae, cladocerans, and rotifers, which frequently dominate freshwater plankton communities, meet these requirements. Multiple clonal lines can coexist within each species over extended periods, until either fixation occurs or a sexual phase reshuffles the genetic material. When clones differ in traits affecting interspecific interactions, within-species clonal dynamics can have major effects on the population dynamics. We first consider a simple predator-prey system with two prey genotypes, parameterized with data on a well-studied experimental system, and explore how the extent of differences in defense against predation within the prey population determine dynamic stability versus instability of the system. We then explore how increased potential for evolution affects the community dynamics in a more general community model with multiple predator and multiple prey genotypes. These examples illustrate how microevolutionary "details" that enhance or limit the potential for heritable phenotypic change can have significant effects on contemporaneous community-level dynamics and the persistence and coexistence of species.