Collaborative Research: Rapid evolution and species coexistence in an orchard fly system

About This Grant

Competition between species shapes the ecological communities all around us, determining which species are common and which are rare, which coexist, and which exclude one another. Rarely do ecologists recognize that as species compete over multiple generations, they are simultaneously evolving, and that this evolution involves traits that determine species’ competitive outcome and their ability to coexist. Importantly, such rapid evolution may also determine the effectiveness of biocontrol agents targeting crop pests, the resistance of gut bacterial communities to invading pathogens, and the persistence of species threatened by biological invasions. Thus, better understanding of how competition plays out as species evolve to one another is important for both our basic understanding of ecological communities and the applications of this knowledge in agriculture, nature conservation, and health. In this project, researchers will measure how rapid evolution of orchard flies in response to their competitors determines (1) how traits and genetic factors seasonally evolve over summer and fall, (2) their winning and losing in competition, and (3) their ability to coexist. The project will train a postdoctoral scientist, graduate and undergraduate students and form the basis of outreach efforts to nearby community, and a 4-year college, high school students and the public. The research will integrate theory and field experiments in the northeastern United States to address three questions: (1) Does rapid evolution shape competitive trajectories and species coexistence? (2) What eco-evolutionary mechanisms, phenotypic traits, and genomic architecture shape competition-induced evolution? And (3) How does the richness of competitors shape these eco-evolutionary dynamics? These questions will be answered by comparing the competitive population dynamics of four pairs of drosophilid fly species in experiments manipulating the competitors’ ability to evolve to one another. Evolutionary mechanisms will be identified by allowing competition to select individuals when their populations are common and rare, and evaluating the genomic architecture and phenotypic trajectories of the evolutionary response. Mathematical models informed by the experiments will quantify the specific eco-evolutionary mechanisms operating in the system. Finally, field experiments with up to six species will be used to evaluate how the number of fly species in the community determines how evolution to competitors shapes the dynamics of the community as a whole. Integrating across these project activities, the work will rigorously quantify how rapid evolution shapes species coexistence, and provide among the most comprehensive empirical tests of the feedback between ecology and evolution. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.