The Japan Times, February 17, 1999

Researchers doubt claim Neanderthals could talk

BERKELEY, Calif. (UPI-Kyodo) Three graduate students at the University of California are disputing the claim that our early ancestors known as Neanderthals could talk.
In a report in Tuesday's issue of the Proceedings of the National Academy of Sciences, graduate students David DeGusta, Henry Gilbert and Scott Turner rebut the 1998 assertion by Duke University researchers.
The earlier conclusion, published in April in the same journal, was based on an analysis of the size of the Neanderthals' hypoglossal canals, holes on both sides of the base of the skull that accommodate the nerves controlling movement of the tongue.
The Duke researchers, who have not responded to requests for comment on the new report, argued that the hypoglossal canals in Neanderthals were close in size to those of early Homo sapiens, and this suggested the Neanderthals may have used language as early as 400,000 years ago.
The Neanderthals apparently branched off from human ancestor species about 400,000 years ago and disappeared 30,000 years ago. They had protruding brows and squat, heavy bodies.
DeGusta said that if the Duke researchers' hypothesis were right, "then humans should have a bigger hypoglossal canal than monkeys," but we don't. He points out that monkeys don't talk, and that "a lot of monkeys and apes have hypoglossal canals within the size range of humans."
Correcting for mouth size just as the Duke researchers did, DeGusta's team found 15 nonhuman primate species whose average hypoglossal canal size is larger than the modern human average. The average gibbon - an ape - has a canal twice as large as that of the average human.
"More than half of the monkeys we measured have hypoglossal canals that are in the modern human size range both absolutely and relative to mouth size," he explained. "So if you find a Neanderthal with a canal also in the modern human size range, did it have humanlike vocal abilities or monkeylike vocal abilities? Based on the hypoglossal canal, you can't say."
DeGusta said the Berkeley team isn't asserting that Neanderthals probably couldn't talk but that the methods used to reach that conclusion were flawed.
"We're saying that you cannot use the size of the hypoglossal canal to tell whether fossil humans such as Neanderthals could talk or not," he said. "The Duke researchers reasoned that speech might require a more coordinated tongue, and a more coordinated tongue might mean a larger hypoglossal nerve supplying the tongue, and a larger hypoglossal nerve might mean a larger hypoglossal canal. So the Duke hypothesis makes two predictions: one, that the size of the canal should be correlated with the size of the nerve, and two that humans should have the biggest canals of all primates, at least relative to mouth size."