A Science Writer Teaches Us Evolutionary Biology Through Culture

Lopez has a new collection of essays called Crossing Open Ground, which offers what he hopes is a non-judgemental view of environmental change and different interactions with animals and the natural world.

Sir David Attenborough, host and producer of the new PBS series "The First Eden," which looks at the natural history of the Mediterranean. This follows his award-winning series for PBS "Planet Earth."

Daniel Lieberman is a professor in the department of human evolutionary biology at Harvard. He says that the notion of "getting exercise" — movement just for movement's sake — is a relatively new phenomenon in human history. His new book is Exercised: Why Something We Never Evolved to Do Is Healthy and Rewarding.