Indirect evolutionary rescue: prey adapts, predator avoids extinction.

Masato Yamamichi,Brooks E. Miner

doi:10.1111/eva.12295

Abstract

Recent studies have increasingly recognized evolutionary rescue (adaptive evolution that prevents extinction following environmental change) as an important process in evolutionary biology and conservation science. Researchers have concentrated on single species living in isolation, but populations in nature exist within communities of interacting species, so evolutionary rescue should also be investigated in a multispecies context. We argue that the persistence or extinction of a focal species can be determined solely by evolutionary change in an interacting species. We demonstrate that prey adaptive evolution can prevent predator extinction in two-species predator–prey models, and we derive the conditions under which this indirect evolutionary interaction is essential to prevent extinction following environmental change. A nonevolving predator can be rescued from extinction by adaptive evolution of its prey due to a trade-off for the prey between defense against predation and population growth rate. As prey typically have larger populations and shorter generations than their predators, prey evolution can be rapid and have profound effects on predator population dynamics. We suggest that this process, which we term ‘indirect evolutionary rescue’, has the potential to be critically important to the ecological and evolutionary responses of populations and communities to dramatic environmental change.

Highlights

The interaction between ecological and evolutionary processes is recognized as having fundamental importance in numerous natural communities and will likely become increasingly relevant as the pace of global change increases (Ellner 2013; Carlson et al 2014)
Existing studies have largely considered a single species evolving in response to an abiotic challenge and have examined how the probability of rescue is affected by the rate of environmental change (Lindsey et al 2013), initial population size (Bell and Gonzalez 2009), founding genetic variation (Agashe et al 2011), spatial structure (Bell and Gonzalez 2011), phenotypic plasticity (Chevin et al 2010), and genetic architecture underlying adaptation
The mechanism underlying indirect evolutionary rescue is as follows: consider a situation in which a predator and its prey experience environmental change that is detrimental to the predator and results in its extinction in the absence of evolutionary change (Fig. 1A)

Summary

Introduction

The interaction between ecological and evolutionary processes is recognized as having fundamental importance in numerous natural communities and will likely become increasingly relevant as the pace of global change increases (Ellner 2013; Carlson et al 2014). We propose a new mechanism of evolutionary rescue in the community context: that a nonevolving predator can be rescued from extinction solely due to the evolution of its prey This overlooked and seemingly counterintuitive outcome, which we term ‘indirect evolutionary rescue’, has a logical mechanistic basis with empirical evidence, and should be explored in future studies of community responses to environmental change. Abrams (2009) briefly mentioned situations in which prey adaptation could increase the maximum mortality at which predators could persist, our goal in this study is to obtain the general mathematical condition for indirect rescue to occur and to draw attention to the indirect rescue phenomenon as relevant in the broader context of community eco-evolutionary responses to environmental change. Vx and Vy are the additive genetic variances for prey and predator traits, respectively

Results

Discussion

Literature Cited