Study Claims Human Predecessors Used Fire 1 Million Years Ago
April 3, 2012

Study Claims Human Predecessors Used Fire 1 Million Years Ago

An international team of researchers say that they have identified one-million year old archaeological evidence that human ancestors used and controlled fire, suggesting that our predecessors may have mastered flame approximately 300,000 years earlier than previously thought.

The study, which was led by researchers from the University of Toronto and Hebrew University of Jerusalem and published in the journal Proceedings of the National Academy of Sciences (PNAS), resulted in the discovery of microscopic traces of wood ash alongside animal bones and stone tools at a cave on the edge of the Kalahari in South Africa, the Canadian university said in an April 2 press release.

In an interview with the CBC's Emily Chung, University of Toronto archeologist and project co-leader Michael Chazan said that in their research, he and his colleagues used materials excavated from Wonderwerk Cave.

The materials were encased in plastic, cut into thin slices, and then examined with microscopes. During their examination, Chazan told Chung that they discovered ash from grass, leaves, and brush, as well as the charred bone fragments and stone tools which they had had shown signs of exposure to flame.

He also told the CBC that the formation of the ash showed them that it had to have originated from within the cave, because the edges were angular, and had they blown in from outside, those edges would have been rounded and showed signs of wear from the environmental conditions.

In order to date the materials, the researchers were forced to use a pair of different geological methods, because according to Chung, they were too old to use radiocarbon dating. The results, she said, "were consistent with the type of stone tools found with the ash, which were known to be made by Homo erectus."

According to Carolyn Y. Johnson of the Boston Globe, the materials were analyzed by researchers at a Boston University laboratory, including research assistant professor Francesco Berna.

Johnson said that Berna and his associated "weren't looking for evidence of fire" while investigating the find, and that the discovery "was so unexpected" that Berna "found himself trying to poke holes in his provocative observation."

Further study allowed them to rule out other causes, such as the fire being created by spontaneously combusting bat droppings, and ultimately Berna said that he and his team realized that "scientifically speaking," it became obvious that "there was fire burning inside the cave of plant material“¦ while humans were dropping tools and bones. It´s not one episode," according to what he told the Boston Globe.

Along with Chazan and Berna, other individuals involved with the research include Paul Goldberg of Boston University; James Brink and Sharon Holt of the National Museum, Bloemfontein; Marion Bamford of the University of Witwatersrand; and Liora Kolska Horwitz, Ari Matmon, and Hagai Ron of Hebrew University. Funding for the study was provided by the Social Sciences and Humanities Research Council of Canada, the National Science Foundation (NSF) and The Wenner-Gren Foundation.

"The control of fire would have been a major turning point in human evolution," Chazan said in a statement. "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."