Ash and charred bone, the earliest known evidence of controlled use of fire, reveal that human ancestors may have used fire a million years ago, a discovery that researchers say will shed light on this major turning point in human evolution.
Scientists analyzed material from Wonderwerk Cave in South Africa, a
massive cavern located near the edge of the Kalahari Desert. Previous
excavations there had uncovered an extensive record of human occupation.Microscopic analysis revealed clear evidence of burning, such as plant ash and charred bone fragments. These materials were apparently burned in the cave, as opposed to being carried in there by wind or water, and were found alongside stone tools in a layer dating back about 1 million years. Surface fracturing of ironstone, the kind expected from fires, was also seen.
Although modern humans are the only human species alive today,
originating about 200,000 years ago, other human species once roamed the
Earth, such as Homo erectus, which arose about 1.9 million years ago. [10 Things That Make Humans Special]
"The analysis pushes the timing for the human use of fire back by 300,000 years, suggesting that human ancestors as early as Homo erectus may have begun using fire as part of their way of life," said researcher Michael Chazan, a paleolithic archaeologist at the University of Toronto and director of the university's archaeology center.
The research team's analysis suggests that materials in the cave were
not heated above about 1,300 degrees Fahrenheit (700 degrees Celsius).
This is consistent with preliminary findings that grasses, brushes and
leaves were burned for these fires — such fuel would not have been
capable of hotter flames.
Fire would have helped early humans stay warm and keep nighttime
predators at bay, and enabled cooking, which would have made food more
digestible. In addition, "socializing around a campfire might actually
be an essential aspect of what makes us human," Chazan said. "The
control of fire would have been a major turning point in human
evolution."
Harvard anthropologist Richard Wrangham has speculated that controlled fires and cooked meat even influenced human brain evolution. He suggests that humans were cooking their prey as far back as the first appearance of Homo erectus
1.9 million years ago, just when humans were experiencing major brain
expansion, and proposes that cooking allowed our ancestors to evolve
larger, more calorie-hungry brains and bodies, and smaller guts suited
for more easily digested cooked food.
"It's possible we may find evidence of fire use as early as Wrangham has suggested," Chazan told LiveScience.
Future research will analyze both earlier and later materials from this
site to see how fire use might have developed over time.
"We're opening the question of how fire fit into the life of early
humans and how that might have changed over time," Chazan said.
The scientists detailed their findings online April 2 in the journal Proceedings of the National Academy of Sciences.
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http://news.yahoo.com/hot-humans-used-fire-1-million-years-ago-191003221.html
I think eventually they will find humans used fire much further back than that over the next few hundred years.
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