Early Humans More Advanced Than Thought10/28/10
THURSDAY, Oct. 28 (HealthDay News) Early humans were using a
highly skilled stone tool sharpening method 75,000 years ago in
Africa, more than 50,000 years earlier than previously believed, a
new study indicates.
This adds more evidence that modern behavior developed over time
during the Middle Stone Age rather than after our ancestors
migrated from Africa to Europe, as some scientists have
Researchers from the University of Colorado at Boulder
discovered that the delicate technique -- called "pressure flaking"
-- was used by anatomically modern humans at Blombos Cave in South
Africa during the Middle Stone Age. Previously, the earliest
evidence of pressure flaking was from 20,000 years ago in France
"This finding is important because it shows that modern humans in South Africa had a sophisticated repertoire of tool-making techniques at a very early time," study co-author Paola Villa, a curator at the University of Colorado Museum of Natural History, said in a university news release.
"This innovation is a clear example of a tendency to develop new functional ideas and techniques widely viewed as symptomatic of advanced, or modern behavior," she added.
Pressure flaking "takes place when implements previously shaped
by hard stone hammer strokes followed by softer strikes with wood
or bone hammers are carefully trimmed on edges by directly pressing
the point of a tool made of bone on the stone artifact," according
to background material in the study. Many stones -- with the
exception of jasper, obsidian and high-quality flint -- also had to
be heated before pressure flaking, researchers noted.
This technique enables better control of the sharpness,
thickness and overall shape of two-sided items such as spearheads
and stone knives, Villa explained.
The study appears in the Oct. 29 issue of
The Australian Museum has more about
tools and human evolution.
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