A theoretical quantitative genetic study of negative ecological interactions and extinction times in changing environments

Adam G Jones

doi:10.1186/1471-2148-8-119

Abstract

BackgroundRapid human-induced changes in the environment at local, regional and global scales appear to be contributing to population declines and extinctions, resulting in an unprecedented biodiversity crisis. Although in the short term populations can respond ecologically to environmental alterations, in the face of persistent change populations must evolve or become extinct. Existing models of evolution and extinction in changing environments focus only on single species, even though the dynamics of extinction almost certainly depend upon the nature of species interactions.ResultsHere, I use a model of quantitative trait evolution in a two-species community to show that negative ecological interactions, such as predation and competition, can produce unexpected results regarding time to extinction. Under some circumstances, negative interactions can be expected to hasten the extinction of species declining in numbers. However, under other circumstances, negative interactions can actually increase times to extinction. This effect occurs across a wide range of parameter values and can be substantial, in some cases allowing a population to persist for 40 percent longer than it would in the absence of the species interaction.ConclusionThis theoretical study indicates that negative species interactions can have unexpected positive effects on times to extinction. Consequently, detailed studies of selection and demographics will be necessary to predict the consequences of species interactions in changing environments for any particular ecological community.

Highlights

Rapid human-induced changes in the environment at local, regional and global scales appear to be contributing to population declines and extinctions, resulting in an unprecedented biodiversity crisis
The results of the quantitative genetic model of species interactions and environmental change provide some insights into how negative ecological interactions might impact extinction dynamics
If the predator or competitor is causing the deaths of individuals that are poorly adapted to the changing environment, the species interaction probably will facilitate adaptation

Summary

Introduction

Rapid human-induced changes in the environment at local, regional and global scales appear to be contributing to population declines and extinctions, resulting in an unprecedented biodiversity crisis. Existing models of evolution and extinction in changing environments focus only on single species, even though the dynamics of extinction almost certainly depend upon the nature of species interactions. Theory concerned with the effects of evolutionary processes on community dynamics dates back several decades [11], but interest in eco-evolutionary dynamics has intensified dramatically over the last several years [12]. The results of these studies show that community dynamics certainly depend upon the details of evolutionary change in the interacting species. Firm general results are difficult to obtain [12], as they depend upon a number

Methods

Results

Conclusion