Ben Bolker is a theoretical ecologist at McMaster University in Hamilton, Ontario. Starting from degrees in physics and zoology and a general curiosity about biological populations that change through time, he has used mathematical and statistical tools to understand a wide range of ecological, evolutionary, and epidemiological systems. In particular, he has studied the dynamics of disease in organisms as diverse as humans, red grouse, gopher tortoises, and fruit flies. Following a Ph.D. at Cambridge University studying measles epidemics and a postdoctoral fellowship at Princeton studying ecosystem carbon dynamics and competition among plant species, he was an assistant and associate professor at the University of Florida (where he developed his current hyper-diverse range of interests) before moving to McMaster University. Marta Wayne is an evolutionary geneticist at the University of Florida in Gainesville, FL, USA. She first became interested in infectious diseases during her graduate work at Princeton University, when she found an intriguing pattern of molecular evolution in a viral resistance gene in fruit flies. She returned to the subject following a postdoctoral research fellowship in molecular quantitative genetics at North Carolina State University and later tenure at the University of Florida. Wayne is part of a small but energetic group working to develop Drosophila melanogaster and its viruses as a model system to understand host-parasite coevolution. She is also interested in the dynamics of virus evolution in humans.