A new study in Science Advances has shown that early human ancestors of the Old Stone Age were more careful in choosing stones for making tools than experts had believed before. About 2.6 million years ago, these early people learned to strike rocks together to create sharp flakes used for cutting meat. Archaeologists working in Nyayanga, Kenya, found that the stone blades were used to butcher hippos and other large animals near water sources. The researchers discovered that quartzite, a strong rock found in streambeds about 13 kilometers away, was chosen because it made sharper tools. This choice shows that early humans were able to plan ahead and had a mental map of the environment. Because hippo skin is very thick, only extremely sharp blades could be effective for cutting.

The findings also challenge earlier ideas that early people collected materials only within one mile of a site. This research gives the earliest evidence of careful planning and resource selection by human ancestors, almost 600,000 years earlier than previously known. Scholars said this shows advanced thinking in toolmakers of that time. The exact identity of these individuals remains uncertain, but they may have belonged to the Homo group or to another lineage such as Paranthropus. Experts emphasized that this ability to evaluate resources and create better tools played a key role in survival and later human progress.