Kyle S. Brown, who is an archaeologist at the Department of Archaeology, University of Cape Town, in the Republic of South Africa, lead this archaeological study.
Dr. Brown stated, "These people were extremely intelligent. These [ancient peoples] are not the image of the classic cavemen, of brutish people that are stumbling around the landscape and, in spite of themselves, surviving. These are the people that [may have] even colonized the rest of the world.” [National Geographic News (August 13, 2009): “Ancient Weapons Point to First Use of Fire for Tools?”]
Earlier estimates by scientists put the first tools manipulated with fire at about 25,000 years ago. However, this new discovery moves back this data to about 72,000 years ago.
In fact, the scientists add that the ability to manipulate and mold tools with fire could have been first learned as far back as 164,000 years ago.
This international group of scientists found the discovery inside a series of rocky caves along the coast of South Africa.
These ancient tools, located in caves at Pinnacle Point, which is near Mossel Bay, South Africa, show that these ancient humans learned to heat silcrete in order to make it easier to flake it off and, thus, make it easier to shape blades, knives, and other tools.
Silcrete, a very hard substance (similar to flint) that was often used for ancient tools, is formed when silica is dissolved and then re-solidifies as a cement-like substance.
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After making such a tool, these ancient peoples attached it to a handle so it could be used to hunt and butcher animals.
Headed by Dr. Brown, the other researchers involved in the discovery include Curtis W. Marean, Andy I. R. Herries, Zenobia Jacobs, Chantal Tribolo David Braun, David L. Roberts, Michael C. Meyer, Jocelyn Bernatchez
In an associated 8/13/09 article by ScienceNOW Daily News titled “Early Tools Were Born From Fire,” the scientists (from South Africa, the United States, Australia, the United Kingdom, and France, relate a story on the difficulties they were having in recreating the tools these ancient humans were using.
The article explains, “Kyle Brown … and colleagues were trying to recreate the axes and hafted tools they were finding in the Pinnacle Point caves--a site containing many artifacts of early human activity--to learn more about how they were made. One of the local rocks that these early humans fashioned tools from is silcrete…. But when the researchers tried to recreate the tools, they couldn't quite get it right. ‘We were having a really hard time coming up with [something] that looked like what we were finding at the site,’ Brown says.”
Continuing, “So the researchers began experimenting with heat treatment. After much trial and error, they found that it took 20 to 40 kilograms of hardwood and almost 30 hours to create the 300°C temperatures in silcrete needed to fashion tools like those seen at Pinnacle Point. Those conditions alone were a good sign that the stone tools were no campfire accident…. ‘It requires a lot of planning,’ Brown says. ‘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.”
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This discovery of early humans using fire-fashioned tools adds to the evidence that ancient humans had very complex behaviors during this time (over 70,000 years ago).
The abstract to their Science paper states, “The controlled use of fire was a breakthrough adaptation in human evolution. It first provided heat and light and later allowed the physical properties of materials to be manipulated for the production of ceramics and metals.”
“The analysis of tools at multiple sites shows that the source stone materials were systematically manipulated with fire to improve their flaking properties.”
“Heat treatment predominates among silcrete tools at ~72 thousand years ago (ka) and appears as early as 164 ka at Pinnacle Point, on the south coast of South Africa. Heat treatment demands a sophisticated knowledge of fire and an elevated cognitive ability and appears at roughly the same time as widespread evidence for symbolic behavior.”
For additional information on this study, please read the 8/14/09 Scientific American article “Hot Rocks Were Technology Revolution.”