I study speciation, from a broad perspective. Most of the work in the laboratory involves analyses of the genetics of behaviours involved in pre-mating isolation (songs, pheromones) in Drosophila. I am particularly interested in the interplay between genetic variation for such traits within and between species. We use both quantitative and molecular genetic approaches to this, and behavioural studies of variation and selection. I began research by studying hybrid zones in grasshoppers and remain interested in population genetics, geographic variation and hybridisation in crickets, flies and fish. I rely on an extensive network of collaborators and care workers.