But later skulls from the genus Homo, beginning with a 400, 000-year-old skull from Zambia, all have big, humanlike hypoglossal canals.
12.
At that time he called the Duke conclusions based on size comparisons of the hypoglossal canal " a very promising approach ."
13.
This area includes the jugular and hypoglossal canal and the foramen lacerum ( through which the internal carotid artery passes superiorly across ).
14.
"Because nonhuman primates are not known to speak, their hypoglossal canals should be smaller than those in modern humans, " the researchers said.
15.
It occurred to the scientists that the size of the hypoglossal canal might serve as an index of the vocal abilities of modern and early humans.
16.
A research team from the University of California, Berkeley, led by David DeGusta, however, argues that the size of the hypoglossal canal is not an indicator of speech.
17.
Among all those samples, the Berkeley scientists found, the average size of the hypoglossal canals overlapped so strongly that many were larger than human canals while others were smaller.
18.
DeGusta said his Berkeley group tested 30 nonhuman primates, compared to just two in the Duke study, and found 15 of them had hypoglossal canal sizes larger than humans.
19.
He also worked on some devices with radiologist John D . Camp on imaging technology, including techniques that would allow for visualization of the optic canal and hypoglossal canal.
20.
The Duke study speculated that Neanderthals might have been able to talk, based on findings that the average size of their hypoglossal canal was similar to that of modern humans.
