This course is about the exciting progress in natural selection theory after Darwin. Students will read such books as: The Beak of the Finch (Jonathan Weiner), The Selfish Gene (Richard Dawkins), and The Moral Animal (Robert Wright). We will ask: Why is natural selection considered the principle guiding force of evolution? What is the evidence for natural selection? In humans? In nonhumans? What are the different kinds of selection? At what level (s) does selection act? The group? The individual? The gene? Which of these levels is most potent and why? In the life sciences, what relevance does natural selection theory have for pesticide resistance and the development of effective vaccines? In the social sciences, how has natural selection theory been invoked in psychology, economics, and anthropology? Does the notion of selfish genes have any relevance to human behavior? How can behavior be adaptive yet not have any basis in genetic differences among individuals? Why does natural selection often favor flexible as opposed to "innate" responses? What roles are played by culture, learning, development? What is the naturalistic fallacy?