From: Ephrem Tekle (ephrem@dehai.org)
Date: Thu Apr 12 2001 - 16:23:58 EDT
By Malcolm Ritter The Associated Press
May-3 Scientists say they have discovered the earliest well-dated example of
an oyster bar: a fossil reef on Africaıs Red Sea coast where ancestral
humans apparently waded out to collect oysters, clams and crabs some 125,000
years ago.
An ax, made from fine-grained volcanic rock found in a fossil reef on the
Red Sea coast off Eritrea, is shown in this photo from the Center for
Scientific Investigation and Higher Education in Ensenada, Mexico. (R.C.
Walter/AP Photo)
(http://abcnews.go.com/sections/science/DailyNews/ancienthuman_route000503.h
tml)
That shows humans had taken up coastal life 10,000 years earlier than
previously known, and suggests they may have left Africa along the Red Sea
rather than going up the Nile River Valley as is traditionally assumed, the
researchers said.
Coastal Route Out of Africa?
The site, in Eritrea, contains stone tools along with shells but no remains
from whoever made the tools. The toolsı makers were probably early
anatomically modern humans, said Robert Walter ofthe Center for Scientific
Investigation and Higher Education in Ensenada, Mexico. He led the study,
published in Thursdayıs issue of the journal Nature.
The tools include small stone blades and hand-size, teardrop-shaped
stones with sharpened edges. The early humans may have used the tools to
remove shellfish from boulders and to crack or pry open shells, Walter said.
Researchers also found fossils of large land mammals such as elephants,
rhinos and hippos. The ancient humans may have trapped the animals against
the sea and butchered them there, Walter said.
A site in South Africa also shows signs that ancient humans lived along
a coast and harvested shellfish. The researchers noted evidence that this
site is 10,000 years younger than the Eritrea site. But in interviews, other
experts put the difference at about 5,000 years. So the Eritrea site is not
markedly older, they said.
Human Migration Still Not Clear
In either case, the two sites show that coastal living spread rapidly in
Africa, though it probably didnıt begin at the Eritrea site, Walter said.
Since that site falls within the dimly understood period when
anatomically modern humans arose, the work suggests that coastal sites could
reveal new information about the early days of the species, he said.
Walter said he suspects the species arose inland and then migrated to
the coasts, perhaps driven by climate changes that dried up rivers and
lakes. Eventually their coastal settlements may have spread out so much that
some settlers left Africa at the northern or southern edge of the Red Sea,
using an ancient land bridge, he said.
Sally McBrearty, an archaeologist at the University of Connecticut at
Storrs, said she isnıt convinced that humans were harvesting shellfish at
the Eritrea site. Just finding stone tools with shells is not enough for
that conclusion, she said.
For example, it is not clear whether the humans really left the tools
there when the shellfish were alive, she said.
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