Designed for first-year graduate students in ecology, evolution, and behavior. Study of why animals behave the ways they do. Study of the proximate and ultimate issues of animal behavior, how it is acquired and regulated, and how it evolved. Emphasis on integration of proximate and ultimate analyses in the various domains in which animals behave. First part of a two-semester sequence. Three lecture hours and one discussion hour a week for one semester. Biology 384C and 389D may not both be counted. Prerequisite: Graduate standing, and consent of instructor and the graduate adviser.