Science Daily: Early Modern Humans Used Fire To Engineer Tools From Stone; Complex Cognition Older Than 72,000 Years?.
ScienceDaily (Aug. 14, 2009) — Evidence that early modern humans living on the coast of the far southern tip of Africa 72,000 years ago employed pyrotechnology – the controlled use of fire – to increase the quality and efficiency of their stone tool manufacturing process, is being reported in the Aug. 14 issue of the journal Science.
An international team of researchers, including three from the Institute of Human Origins at Arizona State University, deduce that "this technology required a novel association between fire, its heat, and a structural change in stone with consequent flaking benefits." Further, their findings ignite the notion of complex cognition in these early engineers.
"Our illumination of the heat treatment process shows that these early modern humans commanded fire in a nuanced and sophisticated manner," says lead author Kyle Brown, a doctoral candidate at the University of Cape Town, and field and lab director in Mossel Bay, South Africa, for ASU's Institute of Human Origins.
"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," explains Brown.