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Indirect evolutionary rescue: prey adapts, predator avoids extinction.

Yamamichi M, Miner BE - Evol Appl (2015)

Bottom Line: A nonevolving predator can be rescued from extinction by adaptive evolution of its prey due to a trade-off for the prey between defense against predation and population growth rate.As prey typically have larger populations and shorter generations than their predators, prey evolution can be rapid and have profound effects on predator population dynamics.We suggest that this process, which we term 'indirect evolutionary rescue', has the potential to be critically important to the ecological and evolutionary responses of populations and communities to dramatic environmental change.

View Article: PubMed Central - PubMed

Affiliation: Department of Ecology and Evolutionary Biology, Cornell University Ithaca, NY, USA.

ABSTRACT
Recent studies have increasingly recognized evolutionary rescue (adaptive evolution that prevents extinction following environmental change) as an important process in evolutionary biology and conservation science. Researchers have concentrated on single species living in isolation, but populations in nature exist within communities of interacting species, so evolutionary rescue should also be investigated in a multispecies context. We argue that the persistence or extinction of a focal species can be determined solely by evolutionary change in an interacting species. We demonstrate that prey adaptive evolution can prevent predator extinction in two-species predator-prey models, and we derive the conditions under which this indirect evolutionary interaction is essential to prevent extinction following environmental change. A nonevolving predator can be rescued from extinction by adaptive evolution of its prey due to a trade-off for the prey between defense against predation and population growth rate. As prey typically have larger populations and shorter generations than their predators, prey evolution can be rapid and have profound effects on predator population dynamics. We suggest that this process, which we term 'indirect evolutionary rescue', has the potential to be critically important to the ecological and evolutionary responses of populations and communities to dramatic environmental change.

No MeSH data available.


Effects of predator evolution, prey evolution, or both on predator abundance as a function of the magnitude of environmentally imposed predator mortality (me) in eqn (2). X-axis is additional predator mortality due to environmental change (me), and Y-axis is predator equilibrium abundance. Black arrows represent the maximum environmentally imposed mortality at which the predator can persist (). Parameter values are m0 = 0.2, c = 2, and Vx = Vy = 0 or >0, with all other parameters the same as in Fig. 1. (A): No evolution (Vx = Vy = 0). (B): Predator evolution only (Vx = 0 and Vy > 0). (C): Prey evolution only (Vx > 0 and Vy = 0). (D) With both predator and prey evolution (Vx > 0 and Vy > 0).
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fig02: Effects of predator evolution, prey evolution, or both on predator abundance as a function of the magnitude of environmentally imposed predator mortality (me) in eqn (2). X-axis is additional predator mortality due to environmental change (me), and Y-axis is predator equilibrium abundance. Black arrows represent the maximum environmentally imposed mortality at which the predator can persist (). Parameter values are m0 = 0.2, c = 2, and Vx = Vy = 0 or >0, with all other parameters the same as in Fig. 1. (A): No evolution (Vx = Vy = 0). (B): Predator evolution only (Vx = 0 and Vy > 0). (C): Prey evolution only (Vx > 0 and Vy = 0). (D) With both predator and prey evolution (Vx > 0 and Vy > 0).

Mentions: As in the previous model, r(x) is a decreasing function of x, and here we assume f(x, y) = Ge(y – x), r(x) = 1 – ax, and m1(y) = ecy for the following analyses, where G is the attack rate coefficient, a is the prey defense cost coefficient, and c is the predator counter-defense cost coefficient. We chose an exponential function for the predator cost function because it should be always positive. We assume that predator mortality m consists of a basal mortality m0 under reference environmental conditions, combined with an additional mortality me due to abrupt environmental change that is detrimental to the predator (thus, m = m0 + me). We explore the effects of predator evolution, prey evolution, or both on predator abundance following increased predator mortality due to sudden environmental change (Fig. 2). We first calculate equilibrium abundances and trait values when both traits can evolve and m0 = 0.2 and me = 0, and then apply additional mortality with a range of positive values for me to evaluate the relative importance of indirect versus direct evolutionary rescue.


Indirect evolutionary rescue: prey adapts, predator avoids extinction.

Yamamichi M, Miner BE - Evol Appl (2015)

Effects of predator evolution, prey evolution, or both on predator abundance as a function of the magnitude of environmentally imposed predator mortality (me) in eqn (2). X-axis is additional predator mortality due to environmental change (me), and Y-axis is predator equilibrium abundance. Black arrows represent the maximum environmentally imposed mortality at which the predator can persist (). Parameter values are m0 = 0.2, c = 2, and Vx = Vy = 0 or >0, with all other parameters the same as in Fig. 1. (A): No evolution (Vx = Vy = 0). (B): Predator evolution only (Vx = 0 and Vy > 0). (C): Prey evolution only (Vx > 0 and Vy = 0). (D) With both predator and prey evolution (Vx > 0 and Vy > 0).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4561568&req=5

fig02: Effects of predator evolution, prey evolution, or both on predator abundance as a function of the magnitude of environmentally imposed predator mortality (me) in eqn (2). X-axis is additional predator mortality due to environmental change (me), and Y-axis is predator equilibrium abundance. Black arrows represent the maximum environmentally imposed mortality at which the predator can persist (). Parameter values are m0 = 0.2, c = 2, and Vx = Vy = 0 or >0, with all other parameters the same as in Fig. 1. (A): No evolution (Vx = Vy = 0). (B): Predator evolution only (Vx = 0 and Vy > 0). (C): Prey evolution only (Vx > 0 and Vy = 0). (D) With both predator and prey evolution (Vx > 0 and Vy > 0).
Mentions: As in the previous model, r(x) is a decreasing function of x, and here we assume f(x, y) = Ge(y – x), r(x) = 1 – ax, and m1(y) = ecy for the following analyses, where G is the attack rate coefficient, a is the prey defense cost coefficient, and c is the predator counter-defense cost coefficient. We chose an exponential function for the predator cost function because it should be always positive. We assume that predator mortality m consists of a basal mortality m0 under reference environmental conditions, combined with an additional mortality me due to abrupt environmental change that is detrimental to the predator (thus, m = m0 + me). We explore the effects of predator evolution, prey evolution, or both on predator abundance following increased predator mortality due to sudden environmental change (Fig. 2). We first calculate equilibrium abundances and trait values when both traits can evolve and m0 = 0.2 and me = 0, and then apply additional mortality with a range of positive values for me to evaluate the relative importance of indirect versus direct evolutionary rescue.

Bottom Line: A nonevolving predator can be rescued from extinction by adaptive evolution of its prey due to a trade-off for the prey between defense against predation and population growth rate.As prey typically have larger populations and shorter generations than their predators, prey evolution can be rapid and have profound effects on predator population dynamics.We suggest that this process, which we term 'indirect evolutionary rescue', has the potential to be critically important to the ecological and evolutionary responses of populations and communities to dramatic environmental change.

View Article: PubMed Central - PubMed

Affiliation: Department of Ecology and Evolutionary Biology, Cornell University Ithaca, NY, USA.

ABSTRACT
Recent studies have increasingly recognized evolutionary rescue (adaptive evolution that prevents extinction following environmental change) as an important process in evolutionary biology and conservation science. Researchers have concentrated on single species living in isolation, but populations in nature exist within communities of interacting species, so evolutionary rescue should also be investigated in a multispecies context. We argue that the persistence or extinction of a focal species can be determined solely by evolutionary change in an interacting species. We demonstrate that prey adaptive evolution can prevent predator extinction in two-species predator-prey models, and we derive the conditions under which this indirect evolutionary interaction is essential to prevent extinction following environmental change. A nonevolving predator can be rescued from extinction by adaptive evolution of its prey due to a trade-off for the prey between defense against predation and population growth rate. As prey typically have larger populations and shorter generations than their predators, prey evolution can be rapid and have profound effects on predator population dynamics. We suggest that this process, which we term 'indirect evolutionary rescue', has the potential to be critically important to the ecological and evolutionary responses of populations and communities to dramatic environmental change.

No MeSH data available.