I work on the population genetics of pathogen invasions. Presently I work on the ash dieback pathogen and wild-agricultural introgression in sugar beet rust. I use population genomics and evolutionary biology to understand the roles of different genes in pathogen invasion and success. The overarching focus of these projects continues to be to apply population genetic approaches to genomes to understand adaptive evolution with a special focus on the relative contribution of the five evolutionary forces and the role of sex in hybridisation and genetic introgression.