Humans have really large butts. Your cat or dog, by contrast, has a very tiny bottom. Chances are you’ve never stopped to think about how unique your own derriere is. Primate species are unique in having distinctive buttock anatomy—our buttocks allow us to sit upright without resting our weight on our feet, the way our pets do. Human buttocks, which are particularly muscular and well-developed, empower us to be bipedal, and propel us forward in walking and running. Read more