Species interaction can be drivers of adaptive evolution, exerting selective pressures that can change traits of interacting species. The resulting change depends on the balance between costs and benefits associated with the interaction. Our goal is to understand how traits involved in the interaction change when interaction partners exert contrasting selective pressures. We developed an eco-evolutionary model to study how a plant’s trait changes given the interaction with two pollinators, each one also acting as a seed predator or an herbivore. From the plants’ perspective, contrasting selective pressures exists due to benefits from the interaction provided by pollination and costs that are associated with seed predation and herbivory. We are specifically interested in the conditions under which natural selection favors plants with traits more suitable for one of the pollinator species versus plants with traits that allow them to interact with both pollinator species. We investigate what processes can influence the coexistence between species and their persistence given differences in the costs and benefits associated with the interaction with each pollinator.
Results/Conclusions
We found that trait matching plays a determining role in species coexistence and persistence. For some combinations of optimal trait values between species there is extinction of one of the pollinators, driven by indirect pollinator competition mediated by the plant species. We show there is a particular combination of optimal traits between pollinators and plants that leads to species coexistence, favoring anti-matching between the optimal trait values of each pollinator. We define anti-matching as the condition where the seed-predator pollinator is favored by a plant trait that leads to the maximum degree of pollination by the herbivore-pollinator and vice-versa. This anti-matching condition we report correspond to the maximum degree of plant trait distribution. We believe these wider trait distribution might balance the costs from predation and herbivory while favoring the maximization of benefits from pollination of both species. We discuss the implications of our results to the maintenance of trait diversity and coexistence of interaction partners.