For the John Templeton Foundation, I wrote an exploration of the early cognitive developments of ancient human ancestors.
The first human inhabitants of the Olduvai Gorge left no lasting monuments apart from their stone tools and a few of their bones that survived to become fossils. Beginning around two million years ago, the 30-mile ravine in East African’s Great Rift Valley was home to successive waves of early humans: first Homo habilis, then Paranthropus boisei, and later Homo erectus. Since they were first explored by modern archaeologists in 1911, the gorge’s sediments have yielded dozens of key discoveries in the story of early humans’ physical and cognitive evolution. In 2019, the Olduvai finally got its monument, in the form of a pair of colossal 5,000-pound skulls — one of Paranthropus boisei and one of Homo habilis — sculpted by the Tanzanian artist Festo Kijo sitting atop a plinth along the tourist road between Serengeti National Park and the Ngorongoro Crater. The monument was one small facet of a three-year, $4.6 million project led by Nick Toth and Kathy Schick of the Stone Age Institute and Indiana University to support scientific research into how human cognition evolved, as well as public outreach to help people learn about who these early humans and pre-humans were, and what they have to teach us.
The brains of Homo sapiens are, compared to other primates, both large and costly, accounting for five percent of our body weight but using 25 percent of our energy. For our species, the energy outlay reaps dividends; our brains allow us to plan, cooperate, make, and use tools in ways that are unmatched by any other species. But how did this come to be? Toth and Schick believe that increased brain size wasn’t the fundamental cause of our cognitive evolution. Rather, they believe that physical changes to early human brains were the result of prior behavioral changes and subsequent adaptations into the niche they had created. For the project, Toth and Schick leveraged their relationships with archaeologists working at three important early human sites to help flesh out the picture of early human cognitive evolution.