THE STUDY “4,300-Year-Old Chimpanzee Sites and the Origins of Percussive Stone Technology” by Julio Mercader et al., published in the February 27, 2007, issue of Proceedings of the National Academy of Sciences.
THE MOTIVE Jane Goodall publicized tool use among chimps in the 1960s, but the first written record of it comes much earlier, from a 17th-century Jesuit priest in Sierra Leone who described how a chimp with palm nuts “and with a stone in its hand breaks the nuts and eats them.” How much further back does this habit stretch, and how did chimps acquire the skill? Did they learn tool use from humans, invent it themselves, or did both humans and chimps inherit the trick from a common ancestor who lived more than 5 million years ago? A team of archaeologists led by Julio Mercader of the University of Calgary is seeking answers in what appears to be ...
