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  • A skull that rewrites the history of man

    http://www.independent.co.uk/news/science/a-skull- that-rewrites-the-history-of-man-1783861.html


    A skull that rewrites the history of man

    It has long been agreed that Africa was the sole cradle of human evolution.
    Then these bones were found in Georgia...
    By Steve Connor, Science Editor
    Wednesday, 9 September 2009

    http://www.independent.co.uk/news/science/a- skull-that-rewrites-the-history-of-man-1783861.htm l?action=3DPopup

    One of the skulls discovered in Georgia, which are believed to date
    back 1.8 million years One of the skulls discovered in Georgia, which
    are believed to date back 1.8 million years The conventional view of
    human evolution and how early man colonised the world has been thrown
    into doubt by a series of stunning palaeontological discoveries
    suggesting that Africa was not the sole cradle of
    humankind. Scientists have found a handful of ancient human skulls at
    an archaeological site two hours from the Georgian capital, Tbilisi,
    that suggest a Eurasian chapter in the long evolutionary story of man.

    The skulls, jawbones and fragments of limb bones suggest that our
    ancient human ancestors migrated out of Africa far earlier than
    previously thought and spent a long evolutionary interlude in Eurasia
    - before moving back into Africa to complete the story of man.

    Experts believe fossilised bones unearthed at the medieval village of
    Dmanisi in the foothills of the Caucuses, and dated to about 1.8
    million years ago, are the oldest indisputable remains of humans
    discovered outside of Africa.


    The story of humans unravels

    But what has really excited the researchers is the discovery that
    these early humans (or "hominins") are far more primitive-looking than
    the Homo erectus humans that were, until now, believed to be the first
    people to migrate out of Africa about 1 million years ago.

    The Dmanisi people had brains that were about 40 per cent smaller than
    those of Homo erectus and they were much shorter in stature than
    classical H. erectus skeletons, according to Professor David
    Lordkipanidze, general director of the Georgia National
    Museum. "Before our findings, the prevailing view was that humans came
    out of Africa almost 1 million years ago, that they already had
    sophisticated stone tools, and that their body anatomy was quite
    advanced in terms of brain capacity and limb proportions.

    But what we are finding is quite different," Professor Lordkipanidze
    said. "The Dmanisi hominins are the earliest representatives of our
    own genus - Homo - outside Africa, and they represent the most
    primitive population of the species Homo erectus to date. They might
    be ancestral to all later Homo erectus populations, which would
    suggest a Eurasian origin of Homo erectus."

    Speaking at the British Science Festival in Guildford, where he gave
    the British Council lecture, Professor Lordkipanidze raised the
    prospect that Homo erectus may have evolved in Eurasia from the more
    primitive-looking Dmanisi population and then migrated back to Africa
    to eventually give rise to our own species, Homo sapiens - modern man.

    "The question is whether Homo erectus originated in Africa or Eurasia,
    and if in Eurasia, did we have vice-versa migration? This idea looked
    very stupid a few years ago, but today it seems not so stupid," he
    told the festival.

    The scientists have discovered a total of five skulls and a solitary
    jawbone. It is clear that they had relatively small brains, almost a
    third of the size of modern humans. "They are quite small. Their lower
    limbs are very human and their upper limbs are still quite archaic and
    they had very primitive stone tools," Professor Lordkipanidze
    said. "Their brain capacity is about 600 cubic centimetres. The
    prevailing view before this discovery was that the humans who first
    left Africa had a brain size of about 1,000 cubic centimetres."

    The only human fossil to predate the Dmanisi specimens are of an archaic
    species Homo habilis, or "handy man", found only in Africa, which used
    simple stone tools and lived between about 2.5 million and 1.6 million
    years
    ago.

    "I'd have to say, if we'd found the Dmanisi fossils 40 years ago, they
    would have been classified as Homo habilis because of the small brain
    size. Their brow ridges are not as thick as classical Homo erectus,
    but their teeth are more H. erectus like," Professor Lordkipanidze
    said. "All these finds show that the ancestors of these people were
    much more primitive than we thought. I don't think that we were so
    lucky as to have found the first travellers out of Africa. Georgia is
    the cradle of the first Europeans, I would say," he told the meeting.

    "What we learnt from the Dmanisi fossils is that they are quite small
    - between 1.44 metres to 1.5 metres tall. What is interesting is that
    their lower limbs, their tibia bones, are very human-like so it seems
    they were very good runners," he said.

    He added: "In regards to the question of which came first, enlarged
    brain size or bipedalism, maybe indirectly this information calls us
    to think that body anatomy was more important than brain size. While
    the Dmanisi people were almost modern in their body proportions, and
    were highly efficient walkers and runners, their arms moved in a
    different way, and their brains were tiny compared to ours.

    "Nevertheless, they were sophisticated tool makers with high social
    and cognitive skills," he told the science festival, which is run by
    the British Science Association.

    One of the five skulls is of a person who lost all his or her teeth
    during their lifetime but had still survived for many years despite
    being completely toothless. This suggests some kind of social
    organisation based on mutual care, Professor Lordkipanidze said
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