One of the keys enabling the earliest human ancestors to trade a forest home for more open country may have been the ability to gather underground foods.
Now a team of scientists reports for the first time that in Tanzania our closest living relatives, chimpanzees, are using sticks and pieces of bark to dig for edible roots, tubers and bulbs.
Published the week of Nov. 12 in the online early edition of the Proceedings of the National Academy of Sciences, the study documents the use of digging tools among chimpanzees inhabiting the Ugalla region of western Tanzania. An arid woodland savanna, Ugalla is thought to be an environment similar to those exploited by hominids that eventually evolved into modern humans.
James Moore, a biological anthropologist at the University of California, San Diego, who has been coordinating research at the site since 1989 under the aegis of the Ugalla Primate Project, said the findings are important because they show that digging with sticks is not a uniquely human adaptation and also because they provide additional insights into the role a dietary shift may have played in hominid evolution.
“Chimpanzees are not australopithecines, and we can’t conclude that if they do something today, our ancestors must have done it then. But, when integrated with research on the fossil and paleoecological record, modern analogies are useful for investigating our past,” Moore said. “In this case, the Ugalla chimpanzees suggest that underground resources were within reach of our ancestors with similar brain size and hand morphology.”
