Invasive species provide an opportunity to study evolutionary change due to range movements and the colonization of new environments. Invasive species can also damage ecosystems and so understanding how invasive populations evolve is also important for management. We study demography, selection, sex determination, and responses to pesticide application in native populations of sea lamprey in the Atlantic and in invasive freshwater populations in the Great Lakes. This project is a collaboration with Margaret Docker and Ken Jeffries at the University of Manitoba.