We all assume we know what life is, but the more scientists learn about the living world, the harder it is to define. Whether it’s a fertilized egg or a tree, scientists have had a hard time agreeing on a definition that would universally apply.
In his new book, "Life's Edge: The Search for What It Means to Be Alive," New York Times bestselling author and columnist Carl Zimmer takes readers on a journey from Mother Nature’s most awe-inspiring creations to the most cutting-edge research in search of an answer.
