Evidence from bones
Scientists study ancient bones and fossils to investigate human origins and evolution. They compare the skeletons of ancient and modern humans from different parts of the world. Some think that human fossils from Asia show a smooth transformation from Homo erectus to modern humans. This suggests that modern humans gradually evolved from ancient humans - at least in Asia. But remains of modern-looking humans found in South Africa that date back to about 100,000 years ago suggest a recent African birthplace for Homo sapiens.