We’ve all marveled at the transformation of the caterpillar into the butterfly. We think of it as a singular mystery of nature, but nearly three-quarters of all animal species undergo some form of metamorphosis. In Oren Harman’s new book, "Metamorphosis: a Natural and Human History," he explores the scientific, philosophical, and artistic aspects of transformation. How does it fit with the questions about individuality, struggle, and the life cycle?