Scientists have found evidence in Africa that humans began using fire to create tools nearly 50,000 years earlier than previously thought, a time that marks the turning point when we acquired intelligence and became “uniquely human.”
Before finding the 72,000-year-old cache of stone weapons, scientists had thought people began manipulating fire to create tools in Europe about 25,000 years ago.
But, according to a report in National Geographic News, the new finds suggest that people in what is now South Africa discovered that heating a stone called silcrete would make it easier to flake, allowing them to shape more advanced blades, knives, and other tools.
These early engineers likely used some of these tools, mounted on handles, to hunt and butcher wide range of prey, from the aggressive Cape buffalo to the tiny mole rat, according to the researchers.
This sophisticated control over fire reflects advanced smarts, and marks the turning point when we became “uniquely human,” according to study leader Kyle Brown, an archaeologist at the University of Cape Town in South Africa.
“These people were extremely intelligent. These are not the image of the classic cavemen, of brutish people that are stumbling around the landscape and, in spite of themselves, surviving,” Brown said.
“These are the people that (may have) even colonized the rest of the world,” he added.
As part of the study, the researchers replicated the processes the early Africans likely would have used to make the stone tools.
Heated over a fire pit, the silcrete flaked and took on a glossy red color.
According to Brown, such craftsmanship required thinking ahead, a sign of high intelligence. People had to collect firewood, build the fire, work the stone, and then afix the handle to the stone using natural adhesives.
“Because this is such a sophisticated technology, this is something that would involve language to pass it on to the next generation,” he added.
“Our discovery shows that these early modern humans had this complex cognition,” Brown said.
According to Curtis Marean, project director, “This expression of cognitive complexity in technology by these early modern humans on the south coast of South Africa provides further evidence that this locality may have been the origin location for the lineage that leads to all modern humans, which appeared between 100,000 and 200,000 years ago in Africa.”