National Book Critics Circle Award—2017 Nonfiction Finalist “Nothing less than a tour de force—a heady amalgam of science, history, a little bit of anthropology and plenty of nuanced, captivating storytelling.”—The New York Times Book Review, Editor's Choice A National Geographic Best Book of 2017 In our unique genomes, every one of us carries the story of our species—births, deaths, disease, war, famine, migration, and a lot of sex. But those stories have always been locked