Fuente: CNRS - All themes
  Expuesto el: jueves, 26 de julio de 2012 22:00
  Autor: CNRS - All themes
  Asunto: The appearance of the first cultures of modern hunter-gatherers  of South Africa pushed back by 24,000 years
| Border    Cave, situated in KwaZulu-Natal in the east of South Africa, is an    archeological site that has been undergoing excavation since the 1970s. It    stands out on account of the exceptional conservation of organic matter.    Initial analyses showed that very complex objects and techniques were already    in existence more than 30,000 years ago. However, these conclusions did not    convince the scientific community. Now, new datings and analyses performed by    the researchers demonstrate that around 44,000 years ago a profound    technological transition began, namely the passage from the Middle Stone Age    to the Later Stone Age, which took place between 44,000 and 42,000 years ago.    The archeological material found in several stratigraphic levels shows that    this transition stemmed from a process that arose within the community that    inhabited Border Cave and was not due to the sudden arrival of other human    groups. The objects found in this    cave bear witness to the appearance of new behavioral patterns, similar to    those of present day hunter-gatherers. Among the main innovations that    characterize this technological transition, there is the use of small sized    bows and arrows with bone tips coated with a ricinoleic acid based poison(1).    Previously, the inhabitants of Border Cave used larger stone tips, which were    probably attached to spears. Another notable innovation that appeared at this    time was the production of a pitch produced from the bark of Podocarpus, a    conifer that is very widespread in South Africa, used to fix arrow heads.    This demonstrates an extremely sophisticated know-how. A piece of beeswax, mixed    with toxic resin of Euphorbia(2)    and probably egg, was found wrapped in a cord made of tree bark fibers. This    find, a Stone Age kit for attaching arrow heads or other tools and directly    dated at 40,000 years, represents the oldest known use of beeswax. The    innovations concerning jewelry and decorated objects are also very striking:    the transition to the Later Stone Age was accompanied by the use of ostrich    eggs to produce beads. The similarity between    these objects dated at more than 40,000 years ago and those still used today    by the San, also known as Bushmen, the first people of southern Africa, is    clear. The beating sticks weighted with perforated stones found in Border    Cave are like those still made today. Like the present day San, the    inhabitants of the cave fashioned notches on bones to use as counting or    notation tools. The use of light bows and poisoned arrow heads is also a    striking point of similarity. This shows that the lifestyle of present day    hunter-gatherers of South Africa dates back to at least 44,000 years, and not    20,000 years ago as was previously thought. 
 © Errico/Backwell Objects    discovered in the archeological layers of Border Cave, South Africa. a:    wooden beating stick, b: wooden stick decorated with notches and bearing at    its end residues of ricinoleic acid, c: bone point decorated with a spiral engraving    filled with orange pigment, d: baboon fibula with one edge covered with    notches engraved by four different lithic cutting edges, e: object    constituted of beeswax and plant resin, f: ostrich egg and shell beads. Scale    = 1 cm. - Visual available on    request: phototheque@cnrs-bellevue.fr 
 ©    Villa et al., PNAS 2012 Border    Cave. Top: two chalcedony microliths less than 1 cm, stuck to a piece of    pitch. Bottom: two microliths with probable traces of pitch on their sides,    which indicate a lateral fitting onto a handle. Modified after Villa et al.    in PNAS 2012. Visual available on    request: phototheque@cnrs-bellevue.fr Notes:(1) A hydroxylated    omega-9 fatty acid. References:Early evidence of San    material culture represented by organic artifacts from Border Cave, South    Africa. Francesco d'Errico, Lucinda Backwell, Paola Villa, Ilaria Degano,    Jeannette J. Lucejkog, Marion K. Bamford, Thomas F.G. Higham, Maria Perla    Colombini, Peter B. Beaumont. PNAS, July 2012. Border Cave and the    beginning of the Later Stone Age in South Africa. Paola Villa, Sylvain    Soriano, Tsenka Tsanova, Ilaria Degano, Thomas Higham, Francesco d'Errico,    Lucinda Backwell , Jeannette J. Lucejko, Maria Perla Colombini, Peter    Beaumont, PNAS, July 2012. 
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