Dr. Randolph M. Nesse is a physician who has dedicated his career to establishing evolutionary biology as a basic science for medicine. His research on the neuro-endocrinology of anxiety evolved into studies on evolution and aging. This led to a series of publications that established the field of evolutionary medicine. He investigates how selection shapes mechanisms that regulate defenses such as pain, fever, and anxiety. Other work investigates the origins and functions of emotions and why emotional disorders are prevalent.