14 DAY TRIAL // Archaeologists try to discover the stone tools of our ancestors. But now, they found stone tools made by ancient chimpanzees, fact that rises the question: did humans and chimps inherit some of their complex stone tool-use behaviors from a common ancestor?
The handheld hammers discovered at a chimpanzee settlement in the Ivory Coast, dated 4,300 years old, suggest that the apes made their stone tools on their own, rather than imitating people.
Even if chimps were seen for centuries employing stone tools, researchers thought they just copied the locals cutting open fruit nearby. "The thinking until now was that if modern day chimpanzees use hammers, it was only because they're imitating neighboring farmers," said Julio Mercader, archaeologist at the University of Calgary and co-author of the study. "But what we've found predates farming in the area."
The find indeed boosts the idea that man and chimp have "inherited" the stone use behavior from a common ancestor.
The settlement did not contain chimp remains, but the stone tools found were much too bigger than anything a human could employ comfortably and bore the remains of nuts, which are very appreciated by modern chimps. "This is the only case of any prehistoric, non-human Great Ape tool use ever discovered," said Mercader.
Even today, wild chimpanzees in the area employ hammer tools to crack nuts (photo), in a similar fashion our ancient ancestors did it a few million years ago. The technology is taught, it's not hereditary, and a chimp offspring will dominate it in seven years. "What makes our find different is that we can demonstrate a prehistoric context for this, and that opens many doors," Mercader said.
"Social transmission was the only way for this to happen. It suggests that there is a "culture" link between chimps today and their ancient ancestors, one that could go back even further than a few thousand years. The transition from millions of years ago to the chimpanzees that lived at the ancient settlement would not have been smooth," said Mercader.
"Other apes in nearby areas may not have used the nut-smashing technique at all, and the find asks many questions about why and how this particular group in the Ivory Coast was able to grasp the concept. We used to think that culture and, above anything else, technology was the exclusive domain of humans, but this is not the case." he added.
