Possibility and Diversity are Found in Stephen Jay Gould's Essays.

A look at the vast, bizarre world of insects, and why we can't live without them with Anne Sverdrup-Thygeson author of the new book 'Buzz, Sting, Bite.'

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.

Thor Hanson's new book looks at the evolutionary significance of feathers in birds. Hanson tells Fresh Air that he's amazed by birds' magnitude of feathers, how feathers grow and how they're the "most efficient insulation known."