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Re: [AAT] Hs evolved in coastal location ~71 ka Pinnacle Point S.Africa

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  • Marc Verhaegen
    Early humans tooled up. Sophisticated bladelets suggest that humans passed on their technological skill down the generations. Kerri Smith 7.11.12
    Message 1 of 2 , Nov 8, 2012
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      Early humans tooled up.
      Sophisticated bladelets suggest that humans passed on their technological
      skill down the generations.
      Kerri Smith 7.11.12

      A haul of stone blades from a cave in S.Africa suggests that early humans
      were already masters of complex technology >70 ka.
      The tiny blades ― c 3 cm long on average ― were probably used as tips for
      throwable spears, or as spiky additions to club-like weapons, says Curtis
      27 such blades (microliths) were found in layers of sand & soil c 71 ka,
      representing a timespan of c 11 ky, showing how long humans were
      manufacturing the blades.
      The find lends credence to the idea that early humans were capable of
      passing on their clever ideas to the next generation of artisans, creating
      complex technologies that endured over time.
      John Shea says that it also suggests that "previous hypotheses that
      'early' Homo sapiens differed from 'modern' ones in these respects are
      probably wrong."

      Nature Podcast:
      Curtis Marean tells Kerri Smith about the bladelets his team has
      discovered and what they imply about their makers' minds.
      www.nature.com/nature/podcast <http://www.nature.com/nature/podcast>

      But because the evidence for early human technology is patchy, the idea of
      its continuous cultural transmission has been disputed.
      Some archaeologists argue that human populations could have repeatedly
      devised such complex tools and lost the ability to make them, as the size
      of the population fluctuated over time.
      Chris Stringer: "It is still tricky to know whether this behaviour is
      continually there."
      At this time, human groups were likely to be small, and those with the
      expertise could easily have been wiped out:
      "If you haven't got the population size, knowledge can get lost."

      Making these tools is a multi-step process:
      - First, people would have collected a rock called silcrete, and then
      heat-treated it to make it easier to flake into bits.
      - Then, they would have used a larger rock to flake off sharp slivers of
      rock, blunted them on one side, and used them as blades on composite

      Marean thinks these people probably had to be able to talk to each other
      for such a process to be transmissible:
      "You have to have high-fidelity transmission of a process like that.
      In order for it to be communicated across generations, we think they
      almost certainly had complex language."
      But even this might not count as evidence for 'complex thought'.
      Some scholars want to see evidence of symbolism (art, or ornaments) in
      order to grant this.
      Nonetheless, the weapons made these early humans a force to be reckoned
      The flakes are "very small & light, and that suggests that they were
      components on a dart or spear that could be thrown a long distance."
      Did Hs use such spear-throwing technology to outsmart Hn when they spread
      out of Africa and into Europe c 100 ka?
      The spear points that Hn used were too unwieldy & heavy to be thrown:
      "If you come up against a competitor that has a spear thrower, you're at a
      distinct disadvantage."

      But Shea isn't so sure that microliths were the clincher for Hs' success
      against other hominin populations.
      It's not clear that they brought this technology into Europe:
      "Microliths seem to show up much later than first appearance dates for Hs
      fossils in most parts of Eurasia."
      And Stringer is keen that archaeologists don't underestimate the Hn.
      Their archaeological record is also incomplete, and more data is needed to
      understand whether their cognitive skills were also getting more complex:
      "I’m trying to be fair to the Neanderthals."

      Nature doi 10.1038/nature.2012.11765

      KS Brown cs 2012 Nature doi 10.1038/nature11660
      A Powell cs 2009 Science 324:1298­1301


      An early and enduring advanced technology originating 71,000 years ago in
      South Africa
      Kyle S Brown, Curtis W Marean cs 2012 Nature doi 10.1038/nature11660

      There is consensus that the modern human lineage appeared in Africa before
      100 ka.
      But when did cultural & cognitive characteristics typical of Hs first
      appear? and what was the role these had in the expansion of Hs out of
      - Scientists rely on symbolically specific proxies (eg, artistic
      expression) to document the origins of complex cognition.
      - Advanced technologies with elaborate chains of production are also
      proxies: these often demand high-fidelity transmission & thus language.

      Some argue that advanced technologies in Africa appear & disappear, and
      thus do not indicate complex cognition exclusive to early Hs in Africa.
      The origins of composite tools & advanced projectile weapons figure
      prominently in Hs evolution research, and the latter have been argued to
      have been in the exclusive possession of Hs.

      Here we describe a previously unrecognized advanced stone tool technology
      from Pinnacle Point Site 5­6 on the south coast of S.Africa, originating
      ~71 ka.
      This technology is dominated by the production of small bladelets
      (microliths) primarily from heat-treated stone.
      There is agreement that microlithic technology was used to create
      composite tool components as part of advanced projectile weapons.
      Microliths were common worldwide by the mid-Holocene epoch, but have a
      patchy pattern of first appearance that is rarely earlier than 40 ka, and
      were thought to appear briefly between 65 & 60 ka in S.Africa and then
      Our research extends this record to ~71 ka, shows that microlithic
      technology originated early in S.Africa, evolved over a vast time span
      (~11 ky), and was typically coupled to complex heat treatment that
      persisted for nearly 100 ky.
      Advanced technologies in Africa were early & enduring; a small sample of
      excavated sites in Africa is the best explanation for any perceived
      "flickering" pattern.



      Small lethal tools have big implications for early Hs complexity.
      On the south coast of S.Africa, scientists have found evidence for an
      advanced stone age technology ~71 ka at Pinnacle Point near Mossel Bay.
      This technology, allowing projectiles to be thrown at greater distance &
      killing power, takes hold in other regions of Africa & Eurasia ~20 ka.
      When combined with other findings of advanced technologies & evidence for
      early symbolic behavior from this region, the research documents a
      persistent pattern of behavioral complexity that might signal Hs evolved
      in this coastal location.
      Curtis Marean:
      "Every time we excavate a new site in coastal S.Africa with advanced field
      techniques, we discover new & surprising results that push back in time
      the evidence for uniquely human behaviors."
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