African Artifacts Suggest an Earlier Modern Human

From: Moorad Alexanian (alexanian@uncwil.edu)
Date: Sun Dec 02 2001 - 10:50:27 EST

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    African Artifacts Suggest an Earlier Modern Human

    By JOHN NOBLE WILFORD

    More than 70,000 years ago, people occupied a cave in a high cliff facing the
    Indian Ocean at the tip of South Africa. They hunted grysbok, springbok and
    other game. They ate fish from the waters below them. In body and brain size,
    these cave dwellers were definitely anatomically modern humans.

    Archaeologists are now finding persuasive evidence that these people were
    taking another important step toward modernity. They were turning animal bones
    into tools and finely worked weapon points, a skill more advanced in concept
    and application than the making of the usual stone tools. They were also
    engraving some artifacts with symbolic marks manifestations of abstract and
    creative thought and, presumably, communication through articulate speech.

    The new discoveries at Blombos Cave, 200 miles east of Cape Town, are turning
    long-held beliefs upside down.

    Until now, modern human behavior was widely assumed to have been a very late
    and abrupt development that seemed to have originated in a kind of "creative
    explosion" in Europe. The most spectacular evidence for it showed up after
    modern Homo sapiens arrived there from Africa about 40,000 years ago. Although
    there had been suggestions of an African genesis of modern behavior, no proof
    had turned up, certainly nothing comparable to the fine tools and cave art of
    Upper Paleolithic Europe.

    "I used to accept the `creative explosion' concept for the origin of modern
    human behavior," said Dr. Rick Potts, director of the human origins program at
    the Smithsonian Institution. "Now I think the nails are going into the coffin
    of that hypothesis. We are seeing many elements of modernity that were
    developing much earlier, in Africa, and more gradually."

    One reason Europe's prehistoric surge of creativity held the attention of
    scholars for so long was that it had virtually no serious competition.
    Archaeologists had spent little time digging African sites of that period,
    while every year in Europe they seemed to find more cavern walls adorned with
    painted deer, horses and wild bulls. Enthralled, scholars perhaps could not
    bring themselves to look for earlier and more distant origins of modern
    behavior.

    But after more than a decade of controversy, the South African cave artifacts
    are now being generally accepted as the earliest evidence of such modern human
    behavior. If correct, these and other findings establish that Homo sapiens
    came out of Africa not only with fully modern anatomies, but also with at
    least 30,000 years of experience in modern behavior. Dr. Potts said the
    beginning of this gradual behavioral evolution might reach back more than
    200,000 years.

    Archaeologists have described the new research and their interpretations in
    recent seminars and journal articles. A group led by Dr. Christopher S.
    Henshilwood of South Africa is publishing a comprehensive report in this
    month's issue of The Journal of Human Evolution.

    The report includes an analysis of 28 bone tools and other artifacts from
    Blombos Cave, as well as 8,000 pieces of the iron oxide mineral ocher that
    might have been used for body decorations.

    Taken together with other recent finds in Africa, Dr. Henshilwood's team
    reported, the Blombos evidence "for formal bone working, deliberate engraving
    on ochre, production of finely made bifacial points and sophisticated
    subsistence strategies is turning the tide in favor of models positing
    behavioral modernity in Africa at a time far earlier than previously
    accepted."

    Many other archaeologists specializing in human evolution said the new
    research seemed to dispel previous doubts about the antiquity of the
    artifacts, which have been excavated and argued about since some of the first
    pieces were collected in 1992. Skeptics had suspected that artifacts of more
    recent vintage had somehow intruded into the cave's lower and thus older
    sediments.

    The oldest such tools reliably dated in Africa had been only 25,000 years old.
    The lineage of the first human ancestors is estimated to have diverged between
    five million and seven million years ago in Africa from the line leading to
    apes. Anatomically modern humans, Homo sapiens sapiens, evolved in Africa
    about 150,000 to 100,000 years ago.

    In an interview by telephone from the cave site, Dr. Henshilwood said: "We're
    absolutely convinced of the dating of the tools. Analysis of them makes us
    confident that what we have is evidence of a bone-tool industry, not just
    occasional pieces."

    Most of the bone tools are awls, probably for working leather. But the most
    impressive ones, archaeologists say, are three sharp instruments. The bone
    appears to have been first roughly shaped with a stone blade. Then it was
    finished into a symmetrical shape and polished for hours, most likely with a
    piece of leather and ocher powder. Some etched marks might have identified the
    owner of what were hunting spear points.

    "Why so finely polished?" Dr. Henshilwood asked. "It's actually unnecessary
    for projectile points to be so carefully made. It suggests to us that this is
    an expression of symbolic thinking. The people said, `Let's make a really
    beautiful object.' "

    Like many hunter-gatherer societies, archaeologists say, these cave dwellers
    might have made some of these tools for exchange in long-distance trading.
    Beauty added value to the object, perhaps a value with symbolic meaning.

    As Dr. Henshilwood explained: "Symbolic thinking means that people are using
    something to mean something else. The tools do not have to have only a
    practical purpose. And the ocher might be used to decorate their equipment,
    perhaps themselves. That is a symbol of something else, which we don't
    understand. But it suggests that these people must have had articulate speech
    to conceive and communicate such symbolism."

    Dr. Henshilwood is an archaeologist at the South African Museum in Cape Town
    and an adjunct associate professor at the State University of New York at
    Stony Brook. His co- authors are Dr. Francesco d'Errico of the Institute of
    Prehistory in Talence, France; Dr. Curtis W. Marean of the Institute of Human
    Origins at Arizona State University; Dr. Richard G. Milo of Chicago State
    University, and Dr. Royden Yates, also of the South African Museum.

    Another archaeologist, Dr. Alison Brooks of George Washington University, who
    has reported finding other early examples of African toolmaking in Congo,
    called Blombos Cave "a tremendously exciting site."

    Bone tools were indicative of modern behavior, Dr. Brooks said, because their
    production required a "higher level of planning and conceptualization than
    just knocking off flakes of stone." The toolmaker, she explained, had to have
    "a vision of the object in mind and be able to plan the creation of something
    complicated to solve a particular problem."

    Not everyone is convinced that the Blombos discovery undercuts previous
    theories about the rise of sophisticated human behavior in Europe. Dr. Richard
    G. Klein, an archaeologist at Stanford University who has argued that human
    language and modern behavior appeared suddenly 50,000 years ago as a result of
    a genetic mutation in the brain, said he remained cautiously skeptical.

    Dr. Klein said that he was still unconvinced that the bone tools had not
    originated in younger sediments and then migrated to the layer where they were
    found. And though he was impressed by the report of two pieces of ocher
    engraved in a crosshatched pattern, he questioned why, if the dating was
    correct, similar projectile points were not being found more widely in African
    sites.

    Dr. Henshilwood and colleagues said that a thick layer of yellow sand
    separated the sediment layer in which the bone tools were found from a higher
    layer with evidence of human occupation only 2,000 years ago. No disturbances
    of this distinct break in the sediments, which could have allowed a downward
    movement of younger artifacts, were found in a recent re-examination of the
    cave, the archaeologists said.

    Recent tests, Dr. Henshilwood said, showed that the chemical content of the
    bones in the tools was different from that of bones in the 2,000-year-old
    layer.

    Dr. Marean of Arizona State University said that in the bone tools
    archaeologists were seeing a new picture of modern human evolution. "This puts
    the behavioral evolution in step with the anatomical evolution," he said.

    Copyright 2001 The New York Times Company



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