London: Stone Age "blacksmiths" used fire
to make sharp tools 164,000 years ago -- much earlier than the
scientists thought, a new study has revealed.
Previously the first use of heat treatment was thought
to have been in Europe 25,000 years ago. The technique wasn`t
believed to have been invented until long after ancestors of
modern humans had left Africa and settled in Europe and Asia.
Now, an international team has discovered that people
were using fire to make sharp blades out of poor stone 164,000
years ago, the `New Scientist` reported.
According to scientists, just as raising temperature
can change the properties of iron and other metals, the early
humans heated stone to make it easier to flake -- the process
transformed silcrete into a raw material for tool manufacture.
Lead scientist Kyle Brown of University of Cape Town
in South Africa said: "Our illumination of the heat treatment
process shows that these early modern humans commanded fire in
a nuanced and sophisticated manner.
"We show that early modern humans at 72,000 years
ago and perhaps as early as 164,000 years ago in coastal South
Africa, were using carefully controlled hearths in a complex
process to heat stone and change its properties, the process
known as heat treatment."
In fact, at 47,000 to 164,000 years old, the blades
may date from the dawn of modern human behaviour, involving
not just complex tool use but also language and art, according
to the scientists.
"These people were extremely smart. I don`t think you
could`ve passed down the skills from generation to generation
without language," Brown said.
And, such adaptations may have given the first modern
humans to leave Africa the tools and know-how to conquer the
world. It may also have given them a big advantage over the
resident Neanderthals they encountered.
Added team member Prof Curtis Marean of Arizona State
University in the US: "The command of fire, documented by our
study of heat treatment provides us with potential explanation
for the rapid migration of these Africans across Eurasia.
"They were masters of fire and heat and stone, a
crucial advantage as these tropical people penetrated the cold
lands of the Neanderthal."
The findings are published in the latest edition of
the `Science` journal.