I am an evolutionary ecologist fascinated by the mechanisms underlying biological diversification (adaptation, speciation). To shed light on these mechanisms, my group’s research typically focuses on how distinct ecological conditions can lead to diversifying selection, how populations respond to this selection at the phenotypic level, and on the genetic underpinnings of this divergence. We aim for an integration of diverse analytical approaches, including manipulative field and laboratory experiments, phenotypic investigations, marker-based analyses using high-throughput sequence data, and computer simulations. My classical empirical research system is threespine stickleback fish inhabiting ecologically contrasting habitats, but we currently also study the responses of butterfly species to anthropogenic ecological changes, and I am happy to expand focus to other research systems.