The Evolutionary Ecology of Species Interactions: Shared Mechanisms of Natural Selection and Population Regulation

The evolutionary and ecological dynamics of each species are simultaneously shaped by interactions with abiotic resources and many other species: prey, herbivores, predators, pathogens, and mutualists. In this review, I explore the conceptual linkages and empirical evidence for how ecological and evolutionary dynamics jointly assemble communities across the landscape and foster coexistence among species within communities. The abundances and traits of interacting species jointly shape the dynamics of population regulation and the regimes of natural selection that those interacting species face. While theory focuses primarily on competition, empirical studies on many taxa demonstrate that all types of species interactions play critical roles in excluding some species, fostering the coexistence of other species in various communities, and imposing natural selection that shapes these ecological outcomes. These empirical studies make clear the synergy that emerges from understanding the fitness and trait differences that foster coexistence and impose natural selection between interacting species.