Eco-evolutionary feedbacks, adaptive dynamics and evolutionary rescue theory

Abstract

Adaptive dynamics theory has been devised to account for feedbacks between ecological and evolutionary processes. Doing so opens new dimensions to and raises new challenges about evolutionary rescue. Adaptive dynamics theory predicts that successive trait substitutions driven by eco-evolutionary feedbacks can gradually erode population size or growth rate, thus potentially raising the extinction risk. Even a single trait substitution can suffice to degrade population viability drastically at once and cause ‘evolutionary suicide’. In a changing environment, a population may track a viable evolutionary attractor that leads to evolutionary suicide, a phenomenon called ‘evolutionary trapping’. Evolutionary trapping and suicide are commonly observed in adaptive dynamics models in which the smooth variation of traits causes catastrophic changes in ecological state. In the face of trapping and suicide, evolutionary rescue requires that the population overcome evolutionary threats generated by the adaptive process itself. Evolutionary repellors play an important role in determining how variation in environmental conditions correlates with the occurrence of evolutionary trapping and suicide, and what evolutionary pathways rescue may follow. In contrast with standard predictions of evolutionary rescue theory, low genetic variation may attenuate the threat of evolutionary suicide and small population sizes may facilitate escape from evolutionary traps.

Stochastic game dynamics under demographic fluctuations

“…In particular, mutations that alter the rates of any of these processes trigger a change in the (deterministic) carrying capacities of the mutant population, provided that it succeeds to take over, or of the mixed population in the case of coexistence. Our model implies that adaptation is not a simple process of accumulating beneficial mutations with higher carrying capacities in isolation, but instead an adaptive process that can favor invasion and fixation of mutations that are disadvantageous for the entire population including evolutionary suicide (39). Dominant mutations are bound to take over with certainty under deterministic dynamics.…”

Eco‐evolution on the edge during climate change

“…2), and pre-adapted species invading and dominating a patch could accelerate isolation. evolutionary suicide; Gyllenberg et al 2002, Kokko and López-Sepulcre 2006, Ferriere and Legendre 2013, Hargreaves and Eckert 2014. Eventually, however, patches can become too isolated and high dispersal mortality can select for decreased dispersal (Comins et al 1980, Johnson and Gaines 1990, Gros et al 2006.…”

Cryptic eco‐evolutionary dynamics

“…53,54,[121][122][123][124][125][126] Unfortunately, similar control and replication are lacking in natural systems, making it notoriously difficult to substantiate evolution's likely pervasive, but easily missed, contributions to population persistence. 116,117 Moreover, when evolution turns out to be insufficient for rescue 127 or deleterious, 128 populations may quickly go extinct, and we would be even less likely to account for evolution's effects (i.e., a winnowing bias 48 ). Many of the best known examples of evolutionary rescue involve cases of species coexistence where populations resist or recover from the initial detrimental effects of a new predator or pathogen, [116][117][118] which brings us to eco-evolutionary feedbacks at a community scale.…”