PREHISTORIC humans may have harnessed fire to make hard, sharp stone blades soon after Homo sapiens emerged in eastern Africa 200,000 years ago. This might mean that complex tool use 鈥� and even language and art 鈥� arose far earlier than previously thought.
The idea comes from , an experimental archaeologist at the University of Cape Town, South Africa, whose team found sharp stone blades dating from 47,000 to 164,000 years ago around Still Bay, east of Cape Town. After attempts to make replicas of these tools from the crumbly local stone failed, the team noticed that the ancient blades resembled more modern ones created from heat-treated stone.
When the team heated local rocks to between 300 and 350 掳C for 5 to 10 hours, they became harder and more brittle. When they analysed the ancient tools, the team found changes in the rock suggesting they had been heated (Science, ).
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Brown suggests that forging tools was part of a 鈥渂ehavioural tool kit鈥� that allowed the first modern humans to conquer the world. Others are not convinced. 鈥淪outh Africa is an unlikely place to look for innovations that led to humans dispersing into Eurasia,鈥� says , a palaeoanthropologist at Stony Brook University in New York.