MORE CALORIES THAN RUMP STEAK
Early humans used special bone tools to dig out juicy termites
WASHINGTON (Reuters) Early humans liked termites so much that they made special bone tools to grub out the juicy insects, researchers said Tuesday.
The finding suggests that some of humanity's earliest ancestors had a diet that was more varied and nutritious than was earlier believed, said researchers Lucinda Backwell of the University of the Witwatersrand and Francesco d'Errico of the National Scientific Research Center in Talence, France.
"Previous studies have suggested that modified bones from the Lower Paleolithic (old Stone Age) sites of Swartkrans and Sterkfontem in South Africa represent the oldest known bone tools and that they were used by Australopithecus robustus to dig up tubers," they wrote in their report, published in the Proceedings of the National Academy of Sciences.
"However, our analysis suggests that these tools were used to dig into termite mounds, rather than to dig for tubers."
Chimpanzees are frequently seen using sticks to "fish" for termites, but it has been unclear how much early humans depended on bugs for food and what sort of tools they used to catch them.
Backwell's study suggested that the hominids carefully selected their tools, as thousands of bones of a similar size and shape were found at the site and found to have the distinctive markings made by poking into a termite mound.
Pat Shipman, an anthropologist at Pennsylvania State University who has studied tools at the site, called the research "remarkable" and said it needed to be looked at closely.
The sites are anywhere between 1 million and 1.8 million years old methods of dating them are not precise. Earlier researchers found the bones and determined they had been used to dig up tubers.
Tubers are an important source of food to modern humans as well and include cassava, peanuts and potatoes.
But it is hard to tell what a tool was actually used for. Backwell and D'Errico ran extensive tests on the bone fragments to see what could have caused the marks on them, and did comparisons to make sure that, for example, an animal chewing on them did not make the marks.
The wear pattern most closely resembled that made when a bone tool is used to dig into a termite mound, they decided.
Big, heavy digging sticks are usually used to get at tubers, the researchers said.
Knowing this is important in understanding the diets of human ancestors, the researchers said. "Termites are a valuable source of protein, fat and essential amino acids in the diets of both primates and modern humans," they wrote. "While a rump steak yields 322 calories per 100 grams and cod fish 74, termites provide 560 calories per 100 grams."
They said it is not clear which early humans or human ancestors used the tools at the sites, noting that remains of both Australopithecus robustus and of a species of Homo the group that includes modern humans are there.
Such nutritious food would have been important for the survival of Australopithecus, Shipman said, because the hominids otherwise survived on vegetables they could forage while later species added meat to their diets.
JOHANNESBURG Lucinda Backwell of the University of Witwatersrand demonstrates last February how early humans used bone tools to dig up termites for food. REUTERS PHOTO