Ancient origins of fire use

From Philadelphia, at the annual meetings of the Society for American Archaeology and the Paleoanthropology Society

Human ancestors learned to control fire by around 1.7 million years ago, far earlier than many scientists have assumed, concludes a new analysis of burned stone artifacts from eastern Africa.

Chinese and European sites from as early as 500,000 years ago contain hearths and burned bones widely viewed as evidence of fire use by human ancestors. About 20 years ago, the discovery at two Kenyan sites of baked-earth patches in deposits that are 1.4 million to 1.6 million years old raised the possibility of much earlier control of fire. Many researchers now suspect that those finds resulted from naturally ignited brushfires.

Brian Ludwig of Rutgers University in Frenchtown, N.J., looked for signs of intense heating on nearly 40,000 stone artifacts from sites in eastern Africa dating to between 1.7 million and 1.6 million years ago. At each location, a small proportion of specimens displayed discoloration, rough texture, and distinctive fractures produced by exposure to extreme heat.

“The ability to control but not necessarily to make fire may have been widespread by 1.7 million years ago,” Ludwig holds.

A direct ancestor of Homo sapiens that lived in eastern Africa at that time, Homo ergaster, may have learned to use fire for cooking fibrous plants and for warmth and protection at night, he suggests.

J. Desmond Clark of the University of California, Berkeley disagrees. Brushfires could have created the stone fractures observed by Ludwig, Clark argues.