My group studies the ecological dynamics of natural selection in aquatic ecosystems, focusing, on reciprocal interactions among ecological, ecosystem, and evolutionary dynamics. Such feedbacks are central to understanding evolving biological systems in general, and ecosystem stability and resilience to environmental change in particular. In outdoor aquatic mesocosms we test how contemporary trait evolution of stickleback can affect community structure and ecosystem functioning. In freshwater ponds and lakes in Greenland, we study how variation in predator presence (e.g. Char) can affect the evolution of interactions between stickleback and their prey, and prey evolution (e.g. copepods).