A lively and revelatory journey through the evolution of caretaking on Earth, from animal parents to modern-day humans, making the case that caring for children and each other made us who we are Poison frog fathers carry tadpoles on their backs. Killer whale grandmothers hunt to feed their adult sons. Tropical birds incubate their friends' eggs. Spider moms let their hatchlings eat them alive. Around the world, animals from the exotic to the familiar go to astonishing lengths to keep their young alive. Their biology, brains and behaviors show us what we have in common with other creatures, as well as what's unique about Homo sapiens. With warmth, humor, and occasional run-ins with bodily fluids, science journalist Elizabeth Preston leads a highly accessible tour of cutting-edge research into how and why we and other animals care for young. She discovers that humans evolved to raise our kids in cooperative groups, and that the tools we've inherited for caretaking aren't only for moms or dads--they're the basis for our human society.