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Right-handedness
prevailed 500,000 years ago
Right-handedness is a distinctively human characteristic, with
right-handers outnumbering lefties nine-to-one. But how far back does
right-handedness reach in the human story? Researchers have tried to
determine the answer by looking at ancient tools, prehistoric art and
human bones, but the results have not been definitive. Now, David Frayer,
Professor of Anthropology at the University of Kansas, has used markings
on fossilized front teeth to show that right-handedness goes back more
than 500,000 years.
He is the lead author (with colleagues in Croatia, Italy and Spain)
of a paper published this month in the British journal Laterality.
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New research shows that distinctive markings on fossilised teeth
correlate to the right or left-handedness of individual
prehistoric humans. (Credit: Image courtesy of University of
Kansas) |
His research shows that distinctive markings on fossilised teeth
correlate to the right or left-handedness of individual prehistoric
humans.
"The patterns seen on the fossil teeth are directly and consistently
produced by right or left hand manipulation in experimental work,"
Frayer said.
The oldest teeth come from a more than 500,000-year-old chamber known
as Sima de los Huesos near Burgos, Spain, containing the remains of
humans believed to be ancestors of European Neandertals. Other teeth
studied by Frayer come from later Neandertal populations in
Europe."These marks were produced when a stone tool was accidentally
dragged across the labial face in an activity performed at the front of
the mouth," said Frayer. '
The heavy scoring on some of the teeth indicates the marks were
produced over the lifetime of the individual and are not the result of a
single cutting episode."
Overall, Frayer and his co-authors found right-handedness in 93.1
percent of individuals sampled from the Sima de los Huesos and European
Neandertal sites." It is difficult to interpret these fossil data in any
way other than that laterality was established early in European fossil
record and continued through the Neandertals," said Frayer. This
establishes that handedness is found in more than just recent Homo
sapiens.
"Frayer said that his findings on right-handedness have implications
for understanding the language capacity of ancient populations, because
language is primarily located on the left side of the brain, which
controls the right side of the body, there is a right
handedness-language connection.
-ScienceDaily
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