Our prehistoric human ancestors relied on deliberately modified and sharpened stone tools as early as 3.3 million years ago. The selection of rock type depended on how easily the material could be ...

Our prehistoric human ancestors relied on deliberately modified and sharpened stone tools as early as 3.3 million years ago. The selection of rock type depended on how easily the material could be ...

If you crossed paths with Homo ergaster on an East African plain some 1.5 million to 2 million years ago, its silhouette might look a bit familiar. Long legs, a narrow torso, and a heat-adapted frame ...