Why specialists exist in the face of broad-niched generalists remains a central question for the biological sciences. At a fundamental level, this question underpins most of our theories for why there is so much genetic, phenotypic, and species diversity in nature. Elisa Visher’s work focuses on the nature of trade-offs to resistance and infectivity breadth in host-parasite systems and on the environmental factors that bias systems towards selecting for specialists or generalists. They primarily use experimental evolution techniques in the Plodia interpunctella (Indian meal moth) and baculovirus model system to explore the geometry of trade-offs with host resistance, the effects of spatial structure and host genetic diversity on parasite niche breadth evolution, and the factors driving the coevolution of diversification. For more information about Elisa’s research, see their website.