Cooperation can promote rescue or lead to evolutionary suicide during environmental change

Abstract

The adaptation of populations to changing conditions may be affected by interactions between individuals. For example, when cooperative interactions increase fecundity, they may allow populations to maintain high densities and thus keep track of moving environmental optima. Simultaneously, changes in population density alter the marginal benefits of cooperative investments, creating a feedback loop between population dynamics and the evolution of cooperation. Here we model how the evolution of cooperation interacts with adaptation to changing environments. We hypothesize that environmental change lowers population size and thus promotes the evolution of cooperation, and that this, in turn, helps the population keep up with the moving optimum. However, we find that the evolution of cooperation can have qualitatively different effects, depending on which fitness component is reduced by the costs of cooperation. If the costs decrease fecundity, cooperation indeed speeds adaptation by increasing population density; if, in contrast, the costs decrease viability, cooperation may instead slow adaptation by lowering the effective population size, leading to evolutionary suicide. Thus, cooperation can either promote or—counterintuitively—hinder adaptation to a changing environment. Finally, we show that our model can also be generalized to other social interactions by discussing the evolution of competition during environmental change.

Decreased coevolutionary potential and increased symbiont fecundity during the biological invasion of a legume‐rhizobium mutualism

“…2018). Higher fitness benefits from cooperation could speed adaptation to novel environments if higher benefits from cooperation maintain higher population sizes, allowing a population to better adapt to novel environmental optima (Henriques and Osmond 2020).…”

“…Ensifer medicae genomes from the invaded range are uniquely enriched in binding functions, relative to E. medicae genomes in the native range, which could indicate differences in selection on E. medicae between the ranges (Porter et al 2018). Higher fitness benefits from cooperation could speed adaptation to novel environments if higher benefits from cooperation maintain higher population sizes, allowing a population to better adapt to novel environmental optima (Henriques and Osmond 2020).…”

Social Selection and the Evolution of Maladaptation

“…In extreme cases, selection may decrease population mean fitness enough to lead to population extinction, a phenomenon known as “self-extinction” (Matsuda and Abrams 1994), “evolutionary suicide” (Gyllenberg and Parvinen 2001), or “Darwinian extinction” (Webb 2003). Social interactions are particularly likely to create conditions where selection leads to a decrease in fitness (Matsuda and Abrams 1994; Kokko and Brooks 2003; Fisher and McAdam 2019; Henriques and Osmond 2020). While social effects on the fitness of others may enhance adaptation when the interests of social partners are aligned (Henriques and Osmond 2020), maladaptation and even population extinction are possible when selection leads to the evolution of competitive traits that increase individual fitness at the expense of others (Wright 1969; Matsuda and Abrams 1994; Webb 2003).…”

“…Social interactions are particularly likely to create conditions where selection leads to a decrease in fitness (Matsuda and Abrams 1994; Kokko and Brooks 2003; Fisher and McAdam 2019; Henriques and Osmond 2020). While social effects on the fitness of others may enhance adaptation when the interests of social partners are aligned (Henriques and Osmond 2020), maladaptation and even population extinction are possible when selection leads to the evolution of competitive traits that increase individual fitness at the expense of others (Wright 1969; Matsuda and Abrams 1994; Webb 2003). Such social fitness effects give rise to social selection (West-Eberhard 1979; Wolf et al 1999), which is often inherently frequency-dependent because an individual’s fitness depends not only on its own phenotype but also those of its social partners (Maynard Smith 1982; Sinervo and Lively 1996; Sinervo and Calsbeek 2006).…”

Evolutionary rescue can prevent rate-induced tipping

“…But naturally, whether populations are able to adapt to environmental change depends on their interactions with other species (Bastille-Rousseau et al, 2018;Lavergne et al, 2010;Lawrence et al, 2012;Schoener et al, 2001;Van der Putten et al, 2010). In fact, some studies have tackled evolutionary rescue in a multi-species context (De Mazancourt et al, 2008;Henriques and Osmond, 2020;Kovach-Orr and Fussmann, 2013;Norberg et al, 2012;Northfield and Ives, 2013;Osmond and de Mazancourt, 2013;Petkovic and Colegrave, 2019), some of which focused on predator-prey interactions (Cortez and Yamamichi, 2019;Osmond et al, 2017;Yamamichi et al, 2019;Yamamichi and Miner, 2015). In one of these works, Yamamichi and Miner (2015) demonstrate that rapid evolution of the prey alone can rescue its non-evolving predator from extinction.…”