Modern pyrotechnology has been traced to a cave in South Africa thanks to scientists barbecuing rocks in an experiment worthy of a CSI episode.
Archaeologists were puzzled by stone arrowheads found in a coastal cave near Mossel Bay. How did early hunter-gatherers make such fine hunting gear? History’s detectives tried to re-enact the scene and make blades and bifacial tools themselves, but it proved trickier than anticipated. Finally, they worked out that to fashion the tools early modern humans must have mastered pyrotechnology the controlled use of fire 45,000 years earlier than thought. And in Africa, rather than Europe.
It’s a groundbreaking find. Heat treatment and passing down the technique an act that would probably have required language shows these Middle Palaeolithic-epoch people were pretty clever chaps or, in scientific speak, capable of complex cognition processes.
The tools were uncovered in a cliffside cave at Pinnacle Point, near the seaside town of Mossel Bay in South Africa, by an international team including scientists from the universities ofCape Town,Arizona, Liverpool, New South Wales, Bordeaux and Wollongong.
Details of their discovery were published in a paper titled Fire As an Engineering Tool of Early Modern Humans in the August 14, 2009 issue of the journal Science. The papers lead author, archaeology doctorate student Kyle Brown, of the University of Cape Town, said: These early modern humans commanded fire in a nuanced and sophisticated manner. This is the beginnings of fire and engineering, the origins of pyrotechnology, and the bridge to more recent ceramic and metal technology.
Previously, pyrotechnology was thought to have first occurred in Europe about 25,000 years ago. Now this critical step for humankind is set in Africa, at least 72,000 but possibly up to 164,000 years ago, which is when scientists estimate early humans first moved into the Pinnacle Point cave.
Teams have been working at sites in the area since 1999 as part of the South African Coast Paleoclimate, Paleoenvironment, Paleoecology, Paleoanthropology Project, known as SACP4. Its also been discovered that the prehistoric hunter-gatherers dined on shellfish and adorned themselves in ochre, both significant inthe evolution of human behaviour.
Too Cool for Tools
When researchers tried to make stone tools themselves, they battled. Arrowheads uncovered at the site were made of silcrete, a mix of gravel and sand held together by silica. Scientists tried to find its source, assuming hunters had made the tools by flaking that is, hitting one rock against another until flakes fell off. Then they discovered a big piece of silcrete, about 10cm in diameter, stuck in ash at Pinnacle Point Site 5-6.This triggered the pyrotechnology brainwave, and scientists started playing with fire.
Eventually, barbecuing rocks paid off. The raw stone was buried under a layer of sand and a fire built on top a hot one, requiring up to 40kg of hardwood. The fire’s temperature was slowly increased then slowly cooled so as not to damage the stone. Afterwardsthe silcrete, previously a shoddy material for tools, was transformed its flaking qualities improved, it changed from a yellow to reddish colour and made top-notch bifacial tools and knives heat-treated products that were likely exchanged as items of value.
This explains why people would invest so much effort at wood collection and heat treatment for their production, said director of SACP4Professor Curtis Marean, of theUniversity of Arizona’sInstitute of Human Originsand a co-author on the paper, in a press release. He added the hearths used to test their theory were designed to mimic what people in the past may have done. So, not only did we heat silcrete, but we barbecued (a braai in South Africa) steaks and chops at the same time as measuring the temperature profiles with our thermocouple.
The Science paper concluded that the pyrotechnology scoop adds weight to the theory that modern humans genetic lineage can be traced to the southern tip of Africa.
Professor Mareansaid their mastery of fire was a reasonable explanation for the rapid spread of modern humans over glacial Eurasia: They were masters of fire and heat and stone, a crucial advantage as these tropical people penetrated the cold lands of the Neanderthal.
See the University of Cape Towns report here.