A study released in Science Advances reported that early human ancestors of the Old Stone Age showed greater selectivity in choosing stones for tool production than earlier assumptions had suggested. Around 2.6 million years ago, these early people developed a technique of striking rocks together to produce sharp flakes that could be used for cutting meat. Archaeological analysis in Nyayanga, Kenya, indicates that crafted stone blades were employed to butcher hippos and other large animals near a water source. The team identified quartzite, a durable rock traced to streambeds and sites about 13 kilometers away, as the preferred material for creating sharper tools. According to specialists, this choice demonstrates that early humans had a mental map of the landscape and engaged in planning when selecting resources. Hippo hides are especially thick, so only extremely sharp tools could cut through them, making certain stones more effective for toolmaking than others.

Evidence from the Nyayanga site challenges earlier assumptions that raw materials had been obtained only within one mile of the location. The study provides the earliest archaeological proof of forward planning and deliberate resource selection by human ancestors, predating other examples by roughly 600,000 years. Scholars described this as an indication of cognitive sophistication in early toolmakers. The identity of these individuals has not been confirmed, with possibilities including the Homo group or another lineage such as Paranthropus. The study highlights that reliance on tools within human evolution can be traced back much earlier than earlier research had indicated. Experts emphasized that this aptitude for resource evaluation and innovation created a foundation for later technological progress, with tools remaining a pivotal factor in adaptation and survival throughout evolution.