Predicting evolutionary rescue via evolving plasticity in stochastic environments

TL;DR

This paper models how evolving phenotypic plasticity affects the risk of extinction during environmental change, considering stochastic environmental fluctuations and cryptic genetic variation, providing insights into evolutionary rescue scenarios.

Contribution

It integrates stochastic demography with quantitative genetics to predict long-term persistence under environmental unpredictability with evolving plasticity.

Findings

Reduced environmental predictability increases extinction risk.

Evolving plasticity can both aid and hinder persistence depending on environmental conditions.

Stochastic load during rescue is amplified by high plasticity in unpredictable environments.

Abstract

Phenotypic plasticity and its evolution may help evolutionary rescue in a novel and stressful environment, especially if environmental novelty reveals cryptic genetic variation that enables the evolution of increased plasticity. However, the environmental stochasticity ubiquitous in natural systems may alter these predictions because high plasticity may amplify phenotype-environment mismatches. Although previous studies have highlighted this potential detrimental effect of plasticity in stochastic environments, they have not investigated how it affects extinction risk in the context of evolutionary rescue and with evolving plasticity. We investigate this question here by integrating stochastic demography with quantitative genetic theory in a model with simultaneous change in the mean and predictability (temporal autocorrelation) of the environment. We develop an approximate prediction of long-term persistence under the new pattern of environmental fluctuations, and compare it with numerical simulations for short- and long-term extinction risk. We find that reduced predictability increases extinction risk and reduces persistence because it increases stochastic load during rescue. This understanding of how stochastic demography, phenotypic plasticity, and evolution interact when evolution acts on cryptic genetic variation revealed in a novel environment can inform expectations for invasions, extinctions, or the emergence of chemical resistance in pests.