How can mathematical modeling help to illuminate biological processes? This course examines major topics in biology through the lens of mathematics, focusing on the role of models in scientific discovery. Students will learn how to build and analyze models using a variety of mathematical tools. Particular emphasis will be placed on evolutionary game theory. Specific topics will include: the evolution of cooperation and of social behavior from bacteria to humans; the evolution of multicellularity; the somatic evolution of cancer; virus dynamics (within host and within populations); and multispecies interactions and the evolution of mutualisms.