Ancient Campfires

This information came from This Week in California Wild,
http://www.calacademy.org/thisweek/archive/20040324.html

Barbecued Bones Show Early Mastery Of Fire
The remains of an ancient African barbecue suggest our ancestors had learned to control fire nearly 1.5 million years ago. Using a new method to analyze heated bone, researchers from the Transvaal Museum in Pretoria, South Africa, and Williams College in Williamstown, Pennsylvania, have pushed back the first instance of controlled fire use by a million years. The researchers analyzed burned bones collected in South Africa's Swartkrans region in 1998. Some bones appeared to have been heated to higher temperatures than others. Hearth fires can attain temperatures nearly 300 degrees Celsius higher than brush fires. For this reason, scientists suspected the bones were evidence of early fire use. Now, a technique called electron spin resonance analysis proves that the bones must have been heated to intense campfire temperatures in order to reduce so much of the material to pure carbon. One of two pre-human species living in the area at that time, Australopithecus robustus and Homo erectus, likely cooked the bones. The next-oldest evidence of fire use, in Zhoukoudian, China, is 400,000 to 250,000 years old.

Access the related BBC News article on the first evidence of fire use by humans.
http://news.bbc.co.uk/2/hi/science/nature/3557077.stm