Evolutionary and plastic rescue in multitrophic model communities

Abstract

Under changing environmental conditions, intraspecific variation can potentially rescue populations from extinction. There are two principal sources of variation that may ultimately lead to population rescue: genetic diversity and phenotypic plasticity. We compared the potential for evolutionary rescue (through genetic diversity) and plastic rescue (through phenotypic plasticity) by analysing their differential ability to produce dynamical stability and persistence in model food webs. We also evaluated how rescue is affected by the trophic location of variation. We tested the following hypotheses: (i) plastic communities are more likely to exhibit stability and persistence than communities in which genetic diversity provides the same range of traits. (ii) Variation at the lowest trophic level promotes stability and persistence more than variation at higher levels. (iii) Communities with variation at two levels have greater probabilities of stability and persistence than communities with variation at only one level. We found that (i) plasticity promotes stability and persistence more than genetic diversity; (ii) variation at the second highest trophic level promotes stability and persistence more than variation at the autotroph level; and (iii) more than variation at two trophic levels. Our study shows that proper evaluation of the rescue potential of intraspecific variation critically depends on its origin and trophic location.

Form of an evolutionary tradeoff affects eco-evolutionary dynamics in a predator–prey system

“…The details are likely to be very variable owing to intraspecific variation in evolutionary tradeoffs (36)(37)(38)54). Theory predicts that numerous details can greatly affect eco-evolutionary dynamics (55): tradeoffs between defense cost and resource availability (32,34), interactions between phenotypic plasticity and evolution (33,(56)(57)(58), and spatial heterogeneity and gene flow (59,60). However, empirical studies were lacking.…”

Evolutionary rescue: an emerging focus at the intersection between ecology and evolution

“…Chevin et al [47] like Kovach-Orr & Fussman [42], make the important point that the fate of a population in a changing environment can be affected by phenotypic plasticity (where the phenotype of a given genotype changes with its environment of development) and that this may alter the likelihood of ER. Phenotypic plasticity may also evolve in response to selection further complicating the task of attributing demographic rescue to genetic adaptation, most especially under field conditions where population replication is limited, environmental conditions are not easily controlled, and the measuring of selection and inheritance of traits affecting fitness is difficult at best.…”

Roles of the Environment in Plant Life-History Trade-offs

“…On the one hand, they may evolve as phenotypic plasticity (e.g., bet-hedging) [97][98][99] in responses to selective factors, including reducing parentoffspring conflict or kin competition, the temporal heterogeneity of the environment, such as local population extinction [100][101][102] and avoiding inbreeding depression due to mating between related individuals (for dispersal only; [103]). Hence, seed dispersal promotes adaptation, stability, and persistence [104]. On the other hand, various costs of dispersal have been postulated in theoretical models [such as fleshy fruits dispersed by animals [105], getting lost during displacements, dispersing in fragmented habitats [106], etc.…”