Invasions and extinctions through the looking glass of evolutionary ecology

Abstract

One contribution of 18 to a theme issue 'Human influences on evolution, and the ecological and societal consequences'. Invasive and endangered species reflect opposite ends of a spectrum of ecological success, yet they experience many similar eco-evolutionary challenges including demographic bottlenecks, hybridization and novel environments. Despite these similarities, important differences exist. Demographic bottlenecks are more transient in invasive species, which (i) maintains ecologically relevant genetic variation, (ii) reduces mutation load, and (iii) increases the efficiency of natural selection relative to genetic drift. Endangered species are less likely to benefit from admixture, which offsets mutation load but also reduces fitness when populations are locally adapted. Invading species generally experience more benign environments with fewer natural enemies, which increases fitness directly and also indirectly by masking inbreeding depression. Adaptive phenotypic plasticity can maintain fitness in novel environments but is more likely to evolve in invasive species encountering variable habitats and to be compromised by demographic factors in endangered species. Placed in an eco-evolutionary context, these differences affect the breadth of the ecological niche, which arises as an emergent property of antagonistic selection and genetic constraints. Comparative studies of invasions and extinctions that apply an eco-evolutionary perspective could provide new insights into the environmental and genetic basis of ecological success in novel environments and improve efforts to preserve global biodiversity.This article is part of the themed issue 'Human influences on evolution, and the ecological and societal consequences'.

Phenological shifts of native and invasive species under climate change: insights from the Boechera–Lythrum model

“…There are reasons to expect that invasive species may respond more rapidly than native species to climate change [11]. Additionally, we found that interspecific differences in habitat and life history had strong effects on phenological shifts under climate change-much stronger than enemy release.…”

“…These factors can constrain evolutionary responses to selection (e.g. [83][84][85]) and may favour invasive species over native species with sparse populations [11]. Thus, incorporating delayed evolutionary responses would potentially slow the evolution of flowering time and reduce reproductive fitness in native populations more than introduced populations.…”

Resistance in persisting bat populations after white-nose syndrome invasion

“…The introduction of species to new regions is one such activity that exerts strong selective pressure [52,53], and the introduction of pathogens to novel host communities is no exception [26]. WNS has caused severe declines in North American bats (more than 90% mortality in several species) and has thereby exerted intense selective pressure on bat populations to evolve traits to persist with this pathogen.…”

Human influences on evolution, and the ecological and societal consequences

“…We suggest that the greatest increases in genetic variation will attend contexts where population sizes increase most dramatically, such as for introduced species experiencing 'enemy release' [35,68] and for native species benefiting from 'disappearing diseases' [38]. Increases are also expected when diverse source populations are brought together in new locations [34,69,70] and in the case of exposure to mutagens (e.g. pollution [71,72]).…”