Best Ever Q&A Space Our World Nature Evolution Prehistoric Life Dinosaurs Simple Creatures Insects & Spiders Fish Amphibians & Reptiles Birds Sea Mammals Land Mammals Ecology Animal Behavior Pets Farm Animals Plant Kingdom Plant Life History Science & Technology	Evolution When did our ancestors evolve? What is adaptation? How did the horse evolve? What is natural selection? What does extinction mean? How do we know about the past? What is evolution?   Previous: Back to Evolution Book: Best Ever Q&A Section: Nature Chapter: Evolution