Chimpanzees show a thirst for learning
Wild chimpanzees in Uganda have been caught on tape developing a new drinking utensil: a mixture of moss and folded leaves that they place in their mouths and then dip into water.
Although it has long been understood that chimpanzees learn by observing one another, scientists say this is the first time humans have witnessed the origins of such behavior. A new study in the journal PLOS Biology describes the phenomenon and how the researchers watched it spreading from chimp to chimp.
Previously, the chimps used only leaves to make the tool. It is not clear whether the new mixture is an improvement, but an author of the study, Thibaud Gruber, a primatologist at the University of Neuchâtel in Switzerland, said, “One day the alpha male decided to add some moss, and from that moment it took off.”
The dominant female in the group watched the alpha male, and then tried making the same tool for herself. “Every chimpanzee learned this by observing another,” he said. The chimpanzees, who live in Budongo Forest, have been observed continuously for about 20 years. “For all of us working in the field, we knew for a long time that social learning was happening,” Gruber said. “But we didn’t have this kind of evidence where a new behavior developed before our eyes.”
Toolmaking may have evolved independently
The Levallois technique – which early humans used to make knives and other instruments by flaking off bits of stone – was long thought to have originated in Africa 500,000 to 600,000 years ago, then taken to Eurasia as part of an exodus from Africa. Now a study in the journal Science throws the second part of that assumption into doubt, suggesting that the technique evolved independently on each landmass – and challenging the notion that the movement of ancient humans can be tracked by the tools they used.
Levallois tools and less advanced ones, like hand axes, are seldom found together, so scientists thought that one type of tool replaced the other as the migrants moved north. But archaeologists working in Armenia have now unearthed Levallois tools in the same layer of soil as hand axes. The most likely conclusion, the researchers say, is that the Levallois method was not taken to Eurasia by African migrants, but evolved there gradually and independently.
Either that, or “you have two different groups of hominins with two totally different toolmaking traditions occupying the same landscape at the same time yet never intermixing,” said the study’s lead author, Daniel Adler, an anthropologist at the University of Connecticut. “We don’t find evidence for that sort of thing anywhere in prehistory.”
New York Times