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05/26/2004
Beads and Burning
The completion of the cleaning of Michelangelo’s David in
Florence made the news this week. Restoration of any
masterpiece in the art world is certain to be controversial and
many experts fought this one. However, it seems that the
sculpture came through its “bath” of wet compresses in fine
shape. I’m lucky to have seen the David and another
Michelangelo masterpiece, Creation of Adam, on the Sistine
Chapel’s ceiling before and after it’s controversial restoration.
The Creation of Adam might be interpreted as the ultimate
representation of creationism. Here in the U. S., creationists
continue to try to limit the teaching of evolution in our schools.
In the April 30 issue of Science, a news item states that members
of one far-right party of the ruling coalition government in Italy
sponsored an “Anti-evolution week” earlier this year. Evolution
was described as the “antechamber of Marxism.” Yet the owner
of the Creation of Adam, the Roman Catholic Church, now
endorses the validity of evolution.
While the evidence for evolution is overwhelming, there are
certainly many questions to be answered and gaps to be filled in.
For example, 800,000 years ago the first humans appeared in
Europe. These weren’t the modern variety of humans but they
did come out of Africa and that poses a question. Europe is a
good bit chillier on average than Africa and the question is how
did those early guys and gals managed to cope in the colder
climate. It would certainly have helped if they knew how to use
fire to keep warm and maybe do a bit of cooking.
The most convincing evidence for controlled use of fire only
dates back roughly 250,000 years ago. If true, this would leave
those early brands of humans in Europe about half a million
years without fire. (Less convincing or doubtful evidence has
been reported for sites dating from 300,000-500,000 years ago.)
The best evidence comes from cave sites, where the charred
debris and other artifacts have been preserved and sheltered from
scattering over the intervening millennia.
When those early humans made their way to Europe from Africa,
they traveled through the Middle East, stopping in the area that is
now Israel along the way. The April 30 issue of Science also
contains an article by archeologist Naama Goren-Inbar of
Hebrew University in Jerusalem and his Israeli coworkers. (A
helpful perspective by Michael Balter on this article appears in
the same issue.) They report on their search for evidence of early
controlled use of fire in Israel.
The Israeli workers chose a site in northern Israel known as
Gesher Benot Ya’aqov (GBY for short). GBY is on the shore of
an ancient lake, Lake Hula, and is known for its well-preserved
wood remains. The researchers dug down into the stratified
layers to a depth dated at 790,000 years ago. This was not a cave
site and required a painstaking study. What the workers did was
to collect samples of wood, plant seeds, fragments of fruits and
flint artifacts. They didn’t just collect a few samples, but tens of
thousands of them, noting their locations.
With the help of students and staff, they sorted out the samples
that were burned and those that were unburned. This was a team
of workers from different disciplines ranging from archaeology
to botany. The different areas of expertise were required to
properly identify the samples and the burned condition. The
burned flints, for example, could be identified by such features as
microscopic fire-induced fractures, shrinkage, crazing, cracks
etc. They found that only 4 percent of thousands of wood
samples were burned. Out of over 23,000 samples of fruit
specimens only 8 were burned. Out of 34,000 flint specimens,
less than 650 were burned.
The significant point is that, while there was some overlapping
with unburned samples, the small numbers of burned samples
were concentrated in localized areas. The authors deduce that
the small numbers of burned specimens and their localization are
strong evidence for the presence of hearths. If the fires had been
of natural origins, for example, wildfires resulting from lightning
strikes, one would expect a general burning of the area. Other
possible types of fire include volcanic activity and underground
fires (burning of roots). No evidence indicates any volcanic
activity in GBY and underground fires wouldn’t get hot enough
to cause the cracks and other features in the burned flint samples.
The initial reactions to this revolutionary paper, putting the time
of the first controlled use of fire back three times earlier than
shown previously, seem surprisingly positive for the contentious
field of archaeology. I suspect that the 790,000 years ago date is
within the experimental error of the 800,000 years ago figure for
humans entering Europe. If supported by future work, it now
seems likely that our early cousins had fire to fight off the
sometimes near freezing temperatures they found there.
While these early humans were tooling around Europe, with fire
in hand, their relatives back in Africa weren’t standing still. At
least some of them were evolving into a new breed of human that
would eventually become us modern humans. Fossils and
genetic studies indicate that about 120,000 years ago our
anatomies were pretty much evolved into what we are today.
Then, about 45,000 years ago, we moderns came charging out of
Africa and eventually populated the world.
Then, about 40,000 years ago in Europe there was a big burst in
cave paintings and jewelry that has led some archaeologists,
notably Richard Klein of Stanford University, to propose that
there was the equivalent of a “big bang” in human development
at that time. The speculation is that this burst of creativity was
prompted by some genetic mutation that led to a leap in human
language capability. The implication is that you wouldn’t have
painting and jewelry without language with which to discuss its
symbolism.
Others disagree with this “big bang”, saying there was a gradual
evolution of symbolic thought in Africa well before we began
our trek out of Africa. Now they can point to beads to back up
their claim. In the April 16 issue of Science, a team headed by
Christopher Henshilwood of the University of Bergen in Norway
and the State University of New York, Stony Brook report
finding 41 beads in the Blombos Cave in South Africa. The
layer from which the beads were recovered is dated reliably at
75,000 years ago. The beads are described in the paper as
perforated “tick shells” roughly a quarter of an inch in size.
I would have thought that those were pretty big “ticks” until I
read the perspective on the work by Constance Holden in the
same issue of Science and also visited the National Geographic
Society Web site (the Society helped sponsor Henshilwood’s
projects). It seems that the “tick” is really a small snail,
Nassarius kraussianus. Another bead finding was reported in
March. This was a finding in the Serengeti in Tanzania of only
two small beads made from ostrich eggshell in the shape of
doughnuts. These beads were discovered by a team led by John
Bower of the University of California, Davis.
The age of the ostrich shell beads is not yet determined but that
there is no doubt that they are beads. They were found in
material dated at around 70,000 years ago but there’s concern
they’re so small (about a quarter of an inch) they could have
wormed their way down into older strata. On the other hand,
skeptics accept the age of the Blombos beads but question
whether they are really beads. They argue that the holes are just
worn through at the weakest areas of the shells and are not
manufactured. Henshilwood argues that the beads show signs of
wear as though strung on a thread or rope. Klein, the “big bang”
proponent, contends the wear patterns around the holes in the
beads are from rubbing on the ground.
I told you this field is a contentious one and I’m sure we’ll be
hearing more about beads and fire in the future. Meanwhile, here
in New Jersey, after a day in the 80s, it’s actually quite chilly and
I almost feel like turning our own “fire” back on!
Allen F. Bortrum
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