An analysis of about 3,000 stone tools from a 325,000-year-old archaeological site near the village of Nor Geghi in the Kotayk Province of Armenia challenges the theory held by many scientists that the so-called Levallois stone tool-making technique was invented in Africa and then spread across the world as the human population expanded. This image shows stone tools found at the site of Nor Geghi, Armenia: top – biface tool; bottom – a...