Guests: Paul Ehrlich Author, Human Natures: Genes, Cultures, and the Human Prospect (Island Press, 2000) Bing Professor of Population Studies Professor of Biological Sciences Stanford University Stanford, California Chris Finelli Assistant Professor Louisiana Universities Marine Consortium Chauvin, Louisiana How much do our genes determine our behavior? Is there such a thing as "genetic destiny?" And is evolution merely a biological process, or is it a cultural process as well? In this hour, we'll talk with biologist Paul Ehrlich about human natures, how they change, and about the history and future of human evolution. Plus, an update on the health of the world's coral reefs.