Human ancestors were using fire a million years ago - 300,000 years earlier than believed.
Microscopic traces of wood ash have been found alongside animal bones and stone tools in the Wonderwerk Cave in South Africa, where an extensive record of human occupation has already been established.
Until this discovery, the oldest human use of fire was believed to be about 800,000 years ago, based on charred wood and bones found in Israel.
"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," says University of Toronto anthropologist Michael Chazan.
An analysis of sediment from the cave reveals ash from burned plant remains and charred bone fragments, both which appear to have been
burned locally rather than carried into the cave by wind or water.
The researchers also found extensive evidence of the sort of surface discoloration you'd expect to see after burning. The burned material was some 100 feet inside the cave, making it unlikely that it got there through natural causes.
"The control of fire would have been a major turning point in human evolution," says Chazan.
"The impact of cooking food is well documented, but the impact of control over fire would have touched all elements of human society. Socializing around a camp fire might actually be an essential aspect of what makes us human."
It's been argued in the past, indeed, that cooking may be what gave us the edge over other hominid species, making food easier to digest and therefore effectively more nutritious.