Ash was discovered in a South African cave, and this indicates that humans were cooking with fire one million years ago. This is the earliest use of fire but experts say that more proof is needed to conclude that humans were cooking with fire regularly.
Francesco Berna, an archaeologist, at Boston University in Massachusetts, and his team found ash that was composed of burnt grass, leaves, brush and bone fragments in sediments 30 meters deep inside Wonderwerk Cave, in Northern Cape, South Africa. This cave is one of the oldest known sites of human habitation and shows traces of having been lived in from almost two million years ago.
For now, it’s impossible to say for certain which species of hominin inhabited the cave one million years ago, but clues indicate that it was probably Homo erectus. The ash was well preserved and has jagged edges, implying that it was not burned elsewhere or blown into the cave, which is usually indicated by worn edges.
There were no traces of bat guano, which led the researchers to conclude that the fire was created by hominins and not started inadvertently by nature. They published their findings in the journal Proceedings of the National Academy of Sciences.
The first humans used cooking to make food easier to chew and digest. This allowed them to get more energy from the same amount of food, and spend less time foraging. It has been difficult to pinpoint the exact period when humans made this leap.
Evidence of burning is quickly and easily destroyed by erosion. Other burned remains have been dated 1 million to 1.5 million years ago, in Swartkrans in South Africa, and 700,000 to 800,000 years ago in Gesher Benot Ya`aqov but both of these sites were exposed, implying that lightning could have ignited these fires. This would have been impossible in the Wonderwerk Cave.
The earliest unequivocal evidence for fire-making, cooking and hearths dates back 400,000 years. Further searches are needed to prove that hominins used fire in this way to equivocally conclude that fire was in use one million years ago.