Human smarts got a surprisingly early start
Our ancestors’ ingenuity enabled long-distance treks and artistic endeavors
By Bruce Bower
Archaeological discoveries reported this year broadened the scope of what scientists know about Stone Age ingenuity. These finds move the roots of innovative behavior ever closer to the origins of the human genus, Homo.
Example No. 1 came from Kenya’s Olorgesailie Basin, where fickle rainfall apparently led to a wave of ancient tool and trading advances (SN: 4/14/18, p. 8). Frequent climate swings in East Africa probably stimulated the creation of new types of stone tools and the formation of trading networks by about 320,000 years ago, said a team led by paleoanthropologist Rick Potts of the Smithsonian Institution in Washington, D.C. Soil analyses point to shifts from dry to rainy conditions every few years or decades at Olorgesailie around that time, the researchers noted in Science in March.
Potts has argued since the 1990s that humans and our direct ancestors evolved to deal with frequent environmental shifts, making human evolution a story of “survival of the versatile.” That’s still a controversial idea, but the Olorgesailie finds support Potts’ scenario.
No Homo fossils have been found at the Kenyan location, leaving the toolmakers’ evolutionary ID unknown. But the timing is right for the Olorgesailie folk to have been Homo sapiens (SN: 12/23/17, p. 24).
If they were, Olorgesailie groups heralded later Stone Age artistic innovations by humans elsewhere. A crosshatched design on a rock found in South Africa was made by humans around 73,000 years ago, making it the oldest known drawing, another team reported this year (SN: 10/13/18, p. 6).