Onward and Upward With Chimpanzees
Posted by Richard Conniff on February 14, 2007
It sometimes seems that we are all busy trying to rehabilitate the reputation of chimpanzees, as if they were those cousins we wish we didn’t have but can’t quite make go away. The latest revisionist news is not just that chimps use tools, but that they have been using them for at least 4,300 years. Here’s the press release from Proceedings of the National Academy of Sciences. Note the interesting use of the word “settlement”:
Researchers have found evidence that West African chimpanzees used stone tools to crack nuts 4,300 years ago, pushing chimpanzee tool use back thousands of years and suggesting that chimpanzees developed this behavior on their own or inherited the trait from a common ancestor with humans.
Chimpanzees were first observed using stone tools in the 19th century.
Julio Mercader and colleagues found stone tools at the Noulo site in Ivory Coast, the only known prehistoric chimpanzee settlement. The excavated stones showed the hallmarks of use as tools for smashing nuts when compared with ancient human or modern chimpanzee stone tools. Also, several types of starch grains were found on the stones, which the researchers say is residue derived from cracking local nuts. The tools were found to be 4,300 years old, which, in human terms, corresponds to the later Stone Age and was before the advent of agriculture.
The researchers say these findings add further support to the current body of evidence showing that chimpanzees transmit cultural information. This type of tool use could have originated with an ancestor common with humans, instead of arising independently among hominins and chimpanzees or through imitation of humans.
And here’s the link to the scientific article: http://www.pnas.org/cgi/doi/10.1073/pnas.0607909104