In 1994, an excavation group led by fossil-hunting legend Tim White—“the Steve Jobs of paleoanthropology”—discovered a series of bone fragments in Ethiopia’s Afar region that radiometric dating indicated were 4.4 million years old, more than a million years older than “Lucy,” then the oldest known human ancestor. With this discovery (Ardipithecus ramidus), White and his cohorts had found something deeply unsettling, a rebuke to a half-century of paleoanthropological orthodoxy. They were about to shatter many broad assumptions about human evolution: how we developed opposable thumbs, when we started walking, and, most crucially, whether we were truly descended from a common ancestor that resembled today’s chimpanzee. In short, White’s team would reveal that in the decades after Lucy, paleoanthropologists had been wrong about some basic tenets of human evolution. To say the least, not everyone was happy about that. Fossil Men brings together one of the most consequential scientific discoveries of our time, and the personal stories of an unforgettable cast of characters.