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Skull Find Helps Solve Evolutionary Puzzle
A 2.3 million year-old skull fragment found with work tools of the same epoch may help explain man's
evolution from ape-like creature to intelligent human."The fossils are very revealing," says
TAU Sackler Faculty of Medicine anatomist Prof. Yoel Rak, a member of the international team which made
the discovery in the arid hills of Hadar, Ethiopia. "This is the earliest find ever of the genus
Homo - to which modern humans belong - and indicates the evolution of the species towards thinking and
learning."
The fossil, an upper jaw labeled #666 by the research team, is 700,000 years younger than
the next oldest hominid skull discovered by Rak himself in Ethiopia in 1994 (see TAU News,
Fall/Winter 1994-95), and one million years younger than the famous "Lucy" skeleton found two
decades earlier. The two older specimens belong to the genus Australopithecus
afarensis - a small-brained, upright ape-like creature and one of mankind's earliest known
ancestors.
"The tools found with #666 indicate a level of intelligence which was almost certainly not
present in A. afarensis," says Rak.
"Moreover," he explains, "the short, flat snout and broad, parabolic dental arch of
#666 link it to younger ancestors of modern humans. Its uniqueness lies in the fact that it lacks the
long, narrow palate and projecting face that gives the A. afarensis skull its ape-like appearance.
Basic chopping tools
The tools found together with #666 are of the most primitive kind, indicating some sort of "pebble culture" says Rak. Scattered alongside the Homo jaw were 20 flaked stone tools, probably used for
chopping skin or bones.
Rak explains that rather than concentrating their efforts on trying to find older specimens than the
earliest specimens of A. afarensis, scientists have been concentrating on closing the gaps between the
earlier ape-like creatures and later Homo species. This interim period is considered to encompass key
evolutionary activity, regarding not only the development of humans, but also of side branches of
humanids which subsequently became extinct, such as the clumsy Australopithecus. "It's a
never-ending story," says Rak. He admits, however, that the latest find narrows the gap.
The international research project at Hadar is supported by the Center for Research and Conservation
of Cultural Heritage of Ethiopia's Ministry of Information and Culture. The research was published in
the December issue of The Journal of Human Evolution. The research team was comprised of Prof. William
H. Kimbel, Robert C. Walter, and Donald C. Johanson of the Berkeley-based Institute of Human Origins,
and Erella Hovers, an archeologist at the Hebrew University of Jerusalem.
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| The #666 palate has a short tooth arch that is wide relative to its length, a typical characteristic of the Homo tooth arch. |
For comparison, the tooth arch of A. Afarensis - ape-like in appearance - is very long and narrow relative to its length. |
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