The fascinating science behind our bodies and behaviors and how they link us to our ancient ancestors. What makes us human is cause for surprise. We retain some of the appearances and behaviors of our very ancient ancestors, including early mammals, amphibians, and fish. Yes, we look and act the way we do because of them. This book explains the many puzzling and strange things about us and the weird and wonderful things we do, simply because we're human. A child-sized take on the scientific fields of evolutionary biology and psychology.