Abstract
We investigate the influence of asymmetric interactions on coevolutionary dynamics of a predator-prey system by using the theory of adaptive dynamics. We assume that the defense ability of prey and the attack ability of predators all can adaptively evolve, either caused by phenotypic plasticity or by behavioral choice, but there are certain costs in terms of their growth rate or death rate. The coevolutionary model is constructed from a deterministic approximation of random mutation-selection process. To sum up, if prey’s trade-off curve is globally weakly concave, then five outcomes of coevolution are demonstrated, which depend on the intensity and shape of asymmetric predator-prey interactions and predator’s trade-off shape. Firstly, we find that if there is a weakly decelerating cost and a weakly accelerating benefit for predator species, then evolutionary branching in the predator species may occur, but after branching further coevolution may lead to extinction of the predator species with a larger trait value. However, if there is a weakly accelerating cost and a weakly accelerating benefit for predator species, then evolutionary branching in the predator species is also possible and after branching the dimorphic predator can evolutionarily stably coexist with a monomorphic prey species. Secondly, if the asymmetric interactions become a little strong, then prey and predators will evolve to an evolutionarily stable equilibrium, at which they can stably coexist on a long-term timescale of evolution. Thirdly, if there is a weakly accelerating cost and a relatively strongly accelerating benefit for prey species, then evolutionary branching in the prey species is possible and the finally coevolutionary outcome contains a dimorphic prey and a monomorphic predator species. Fourthly, if the asymmetric interactions become more stronger, then predator-prey coevolution may lead to cycles in both traits and equilibrium population densities. The Red Queen dynamic is a possible outcome under asymmetric predator-prey interactions.
Highlights
Predator-prey interactions are common in natural world and both prey and predator species have showed enormous diversity in their phenotypic traits, such as body size, weight, running velocity, or arms level [1,2,3,4,5]
After branching has occurred in the predator species, we further study the coevolutionary dynamics of a two-predator-one-prey system
If the attack ability of predators and the defense ability of prey all can adaptively evolve, but there are certain costs in terms of the predator’s death rate and prey’s growth rate, firstly we find that evolutionary branching in the prey and predator species is possible
Summary
Predator-prey interactions are common in natural world and both prey and predator species have showed enormous diversity in their phenotypic traits, such as body size, weight, running velocity, or arms level [1,2,3,4,5]. Evolutionary change in either species may evoke an evolutionary change in the other, which changes the original trait value of the first species. In general both prey and predators may experience adaptive changes in their phenotypic traits, either caused by phenotypic plasticity or by behavioral choice [3, 18]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
