Bone is a marvel, an adaptable and resilient building material developed over four hundred million years of evolutionary history. Arguably, no other part of the human anatomy has such rich scientific and cultural significance, both brimming with life and a potent symbol of death. Our species has made instruments and jewelry from bone, put our faith in skull bumps as guides to human behavior, and arranged skeletons into macabre tributes to the afterlife. In this delightful history, Brian Switek explains where our skeletons came from, what they do inside us, and what others can learn about us when these artifacts of mineral and protein are all we've left behind.