Was this cave the site of ancient campfires?

Posted by on April 5, 2012 in Featured, Great Big World | Comments Off

Scientists said that they've found the earliest firm evidence of human ancestors using fire: material about 1 million years old in in Wonderwerk cave. Burned bones and microscopic ash in the dirt suggests fire frequently burned there, apparently under the control of our ancestor Homo erectus, researchers said. (AP Photo/courtesy of Michael Chazen)

When did our ancestors first use fire? That’s been a long-standing question, and now a new study says that our anscestors were buring things 1 million years ago in a South African cave.

The ash and burnt bone samples found there suggest fires burned in that spot — not just one time, but lots of times, researchers said Monday.

The problem for scientists in figuring out when we started using fire is this: If you find evidence of an ancient blaze, how do you know it wasn’t just a wildfire?

The new research makes “a pretty strong case” for South Africa’s Wonderwerk Cave, said Francesco Berna of Boston University.

One expert said the Wonderwerk finding should be studied together with another discovery nearby, which dates back to the same time. Burnt bones also have been found in the Swartkrans cave, not far from the Wonderwerk site, and the combination makes a stronger case than either one alone, said Anne Skinner of Williams College.

A worker takes samples at Wonderwerk cave in South Africa. (AP Photo/courtesy of Michael Chazan)

Another expert unconnected with the work, Wil Roebroeks of Leiden University, said that while the new research does not provide “rock solid” evidence, it suggests our ancestors probably did use fire there.

Those people from long ago probably brought burning material from natural blazes into the cave to establish the fires, said Michael Chazan of the University of Toronto, a study author. Stone tools at the site suggest the ancestors were Homo erectus, a species known from as early as about 2 million years ago.

Berna said it’s unlikely the fires were simply natural blazes, such as from lightning strikes. That’s because the evidence shows repeated fires burned deep inside the cave, he said. The cave entrance is almost 100 feet away, he said.

The scientists also found no sign that the Wonderwerk cave fires were ignited by spontaneous combustion of bat poop, which they called a rare but documented event.

Fire for what? It’s not clear what the fires were used for. While the burnt bones suggest cooking, the ancestors might have eaten the meat raw and tossed the bones into the fire, Berna noted. Other possible uses might be warmth, light and protection from wild animals, he said.

In a statement to The Associated Press, Roebroeks and Paola Villa of the University of the Witwatersrand and the University of Colorado Museum, said that while the new study probably demonstrates use of fire, they’d like to see signs of preparations like a hearth — a cooking area — to be sure.

In any case, they said, the work does not show that human ancestors were using fire regularly throughout their range that long ago. In a paper published last year, they traced such habitual use of fire to about 400,000 years ago.



Journal website: http://www.pnas.org

Wonderwerk Cave information:


Reported by MALCOLM RITTER of the Associated Press