Life's Edge

We all assume we know what life is, but the more scientists learn about the living world, the harder they find it to locate the edges of life, where it begins and ends. What exactly does it mean to be alive? Is a virus alive? Is a foetus? Acclaimed New York Times science writer Carl Zimmer investigates what current science has to say on the most fundamental of questions. An utterly fascinating investigation by one of the most celebrated science writers of our time.