Host-parasite interactions and the evolution of immune defense

Parasites and pathogens are ubiquitous and act as an important selection pressure on animals. Here, drawing primarily on our own research, mostly on insects, we illustrate how host-parasite interactions have played a role in the evolution of a range of phenomena, including animal coloration, social behavior, foraging ecology, sexual selection and life-history trade-offs, as well as how variation in host behavior and ecology can drive variation in parasitism risk and host allocation of resources to immunity and other anti-parasite defenses. We conclude by identifying key areas for future study.