The Human LineLife & Evolution Walking upright 4.4 million years agoTurning point Ardipithecus and later australopithecines walk on two legs, freeing the hands for carrying and tool use. ▲ MattersSaveShareTrace roots Longest chain: The Big Bang → First stars ignite → Supernovae seed heavy elements → The Sun forms → Earth forms → First oceans → First life → Photosynthesis evolves → Great Oxidation Event → Complex cells (eukaryotes) → Multicellular life → First animals → Cambrian Explosion → First vertebrates → Jawed fish → Fish walk onto land → The amniotic egg → The Great Dying → Dinosaurs appear → Asteroid ends the dinosaurs → Early primates → Apes split from monkeys → Human line splits from chimpanzees → Walking upright Community notesLoading notes… Learn more ranked by votesDocumenthumanorigins.si.eduWalking upright (Smithsonian Human Origins) ↗Editor's pickBookDaniel LiebermanThe Story of the Human Body ↗Editor's pickVideoSearch on YouTubewhy humans walk upright evolution ↗Editor's pick