Evidence of campfires made by human ancestors has been uncovered in a cave in South Africa, suggesting that the practice may have started one million years ago.
Until now, experts have found little consensus on when our prehistoric cousins figured out how to make sparks for cooking food and keeping warm, according to the study in the Proceedings of the National Academy of Sciences.
Hints of such activity have been found in Africa, Asia and Europe, but the earliest signs of fire were believed to be scorched pot pieces in Israel, dating to around 700,000-800,000 years ago.
Fragments of burnt animal bones and stone tools that appear to be even older have since been found in layers of sediment at the Wonderwerk Cave in north-central South Africa where earlier excavations have shown a significant record of human occupation.
Researchers found "well preserved ashed plant material and burned bone fragments deposited in situ on discrete surfaces and mixed within sediment" in the cave, suggesting small, local fires near the entrance, according to the study.
Some of the fragments show evidence of surface discoloration typical of a controlled burn and not a wildfire or other natural event, it added.
"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, co-director of the project.
Homo erectus is the oldest known early human. With long legs and large brains that resembled modern people they were believed to roam the Earth beginning 1.8 million years ago, long before the Neanderthals.
"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. Socialising around a camp fire might actually be an essential aspect of what makes us human."
The international team of researchers included experts from Boston University, Heidelberg Academy of Science and Humanities in Germany, Hebrew University in Jerusalem, University of the Witwatersrand in Johannesburg and University of Toronto, Canada.