Three-million-year-old tools found in Kenya reveal early humans' ability to cut food, butcher meat, and adapt to new diets.

The meat would then be pounded between stones to tenderize it. The knife and stones are known as the Oldowan tool kit, and likely set the stage for further technology advancement down the line.

Early stone toolmaking marks an important juncture in evolution. The Oldowan stone tools from Hadar, Ethiopia, are among the oldest known, dating back 2.3 million years. Shown from various angles ...