Evidence of humans engineering tools to improve their effectiveness has emerged 30,000 years earlier than previously thought.
A discovery at Pinnacle Point on the South African coast shows early humans fire-treated stones to make tool making more efficient.
The find pinpoints engineering of tools to between 70,000 and 164,000 years ago.
Publishing his findings in the journal Science, “Fire As an Engineering Tool of Early Modern Humans”, archaeologist at the University of Cape Town Kyle Brown explains how his team tried to recreate silcrete – a type of flint – tools found at the site, but were unable to.
“We were having a really hard time coming up with [something] that looked like what we were finding at the site,” he said.
Research revealed that the tools needed to be cured in fire. Using available material, the stones needed to be stoked with 20 to 40 kilograms of hardwood for almost 30 hours to create 300°C temperatures in silcrete to create the tools.
“It requires a lot of planning,” said Brown. “It’s not the kind of thing people would do with an ordinary cooking fire.” Heating makes the stones easier to flake and shape into blades.
“This is a bridging technology between control of fire and the later production of ceramics and metalworking. There’s a long gap, but I think as people begin to look for heat-treatment they’ll begin to see it,” he said.