Early humans were cooking food on an open fire thousands of years before scientists previously thought, two studies suggest.New evidence could shift the birth of the barbecue from China to South Africa and reveals that early humans cooked antelope, other meats and vegetarian dishes.The first study is of what is believed to be a 1 to 1.5 million-year-old South African fire, which could represent the earliest evidence for human-controlled fire.
And the second study, published in the current issue of the journal Science, describes 790,000-year-old hearth fires in Israel, the first evidence for humans using fire in Europe and Asia.
Previously, the earliest controlled fires were thought to have originated in China about 500,000 years ago.
According to a presentation at the Paleoanthropology Society’s annual meeting in Montreal, the South African evidence came from a dark cave called Swartkrans near the city of Sterkfontein in a region known for early hominid finds.
In 1984, researchers found more than 250 charred animal bones in the cave. But it was not until recently that researchers took another look at the bones, using a process called electron spin resonance (ESR), to see how hot the ancient bones got when they were cooked.
ESR looks at the unpaired electrons often found when a stable bond is broken, a measure of how damaged the bones were.
It seems that our distant human relatives, such as Homo ergaster and Homo erectus, liked their meat either very rare or well done.
U.S. chemist Dr Anne Skinner, from Williams College, who was one of the researchers, said the probable antelope bones fell into three categories: unheated, slightly heated and calcined, meaning burnt to a crisp.
“Actually the most interesting bones are not the result of cooking,” Skinner said. “Heating something to 600°C would result in a totally inedible dinner. These [calcined] bones were either refuse after earlier cooking at a lower temperature, or the meat was eaten raw and just the bones put in the fire.”
The fire used to heat the bones was likely to have been man-made, she said, because the site at the time would have been open grassland, and temperatures in grass fires usually only reach 300 to 400°C.
Dr Francis Thackeray of the Transvaal Museum in Pretoria, South Africa, also studied the burned bones.
He does not believe humans over a million years ago actually made fires, rather they might have collected burning branches set alight by lightning strikes and other natural causes.
But humans probably made the fires at the Israeli site, Gesher Benot Ya’ aqov, researchers said.
Burnt wood from a wild olive tree found at the Israeli site (Image: Science)
There, researchers found seeds, cut bones, wood, flint, numerous fruit specimens, and burnt and unburned grains, all in clusters suggesting hearths.
As the site was on the shore of an ancient lake, the organic remains were waterlogged, helping to preserve them.
The early barbecuers at Gesher liked to eat their meat right down to the bone.
“There are indications that meat was consumed, and not only meat,” said lead researcher Associate Professor Naama Goren-Inbar of Hebrew University of Jerusalem’s archaeology institute.
“There are cut marks and cracked bones [indicating] marrow consumption, and the bones were cracked very methodologically. Having a fire around means that some roasting [took place].”
Goren-Inbar added that the ability to control fire marked a turning point in human evolution.
“The role of fire in energy, warmth, cooking, more extensive diet, defence, light, etc. is crucial in everyday life,” Goren-Inbar said. “Some people even make the connection between the presence of fire and the ability of Homo erectus to colonise the old world.”