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One site says new missing link, this one says no

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  • Lowell Baker
    New hominid species not a missing link, scientists say By Devin Powell | Published Fri, Apr 9 2010 12:09 pm WASHINGTON - Two million years ago in South Africa,
    Message 1 of 14 , Apr 11, 2010
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      New hominid species not a missing link, scientists say


      By Devin Powell | Published Fri, Apr 9 2010 12:09 pm

      WASHINGTON - Two million years ago in South Africa, a juvenile ape-like
      creature that walked upright fell down a deep hole and died. His remains
      were buried until 2008, when a 9-year-old boy named Matthew literally
      stumbled upon them - tripping over a log and uncovering a
      remarkably-preserved skull and set of fossils.

      These fossils - and the remains of a middle-aged female adult found nearby -
      reveal an unusual patchwork quilt of features: some primitive and apish,
      others advanced and human-like, in a combination never before seen together
      in the same body.

      Matthew's father, Lee Berger, has raised the possibility that the earliest
      humans may have descended from this new species: Australopithecus sediba.

      "Sediba means natural spring, fountain or wellspring in Sotho, an
      appropriate name for a species that might be the point from which the genus
      Homo arises," Berger said in statement about the find, which will be
      published Friday in Science.

      The first hominids to walk upright 3.5 million years ago, Australopithecus,
      had chimp-sized brains, protruding faces, and feet built for climbing. The
      earliest species thought to be human (or Homo) started to emerge over 2
      million years ago with bigger brains, smaller teeth and longer legs.

      Berger, a paleontologist at the University Institute for Human Evolution at
      the University of the Witwatersrand in Johannesburg, argues that A. sediba
      could have been a link between the Australopiths and the earliest Homos.

      But other researchers find this "missing link" idea hard to swallow.

      "This is an outstanding find and Lee should really be congratulated," said
      renowned paleontologist Meave Leakey, who traveled to Africa to inspect the
      fossils. "However I do not think that they have anything to do with Homo or
      the ancestry of Homo."

      The remarkably complete remains belong to a female adult and a male child,
      both about 4 feet tall, that seem to have fallen into an underground cave.
      Their remains were carried by flowing water into deeper underground hollows
      and slowly buried in mud that turned to rock over the course of time.

      "Normally we have only a hip bone, a skull, a hand bone or a foot bone and
      often we cannot even be sure what species the fossils represent," said
      Leakey. "Here we have a collection of fossils from single individuals that
      are exceptionally well preserved and that, with further work, are likely to
      be even more complete."

      To figure out how old these remains are, the scientists first looked at the
      other bones found nearby - species of hyena and wild ass that appeared in
      Africa around 2.36 million years ago and had disappeared by 1.5 million
      years ago.

      The scientists also dated the remains by calculating the amount of uranium
      and lead encased with them. Over time, uranium breaks down into lead at a
      steady rate - a ticking clock that revealed an age of 2 million years. The
      rocks that formed around the bones confirm this date; they contain traces of
      a reversal of the Earth's magnetic field that happened around 1.9 million
      years ago.

      This timing is problematic for the argument that the new species could be an
      ancestor to the human lineage.

      "We already have good diagnostic jaws of Homo older than this," said William
      Kimbel, director of the Institute of Human Origins at Arizona State
      University in Tempe. "It doesn't strike me as terribly likely that this
      represents a population that was the font from which all later Homo
      evolved."

      Fossil remains show that tool-users with big brains were already walking the
      Earth at this time - such as East Africa's "handy man" (Homo habilis),
      thought to have lived between 2.4 and 1.4 million years ago, and Homo
      erectus, often described as a miniature version of the modern human, the
      earliest fossils of which date back to 1.9 million years ago.

      The immediate ancestor of these early humans has remained a mystery for
      scientists; few fossils have been found of hominids living just before these
      early humans.

      Each of the four outside researchers contacted by this reporter agreed that
      A. sediba is an unlikely root for this branch of early humans. Instead, they
      consider it to be relative - though the closeness of the relationship is up
      for debate.

      Kimbel favors classifying sediba as a sort of sister species to early humans
      that shared a close ancestor.

      "I'd classify it with Homo," said Kimbel, who pointed to features of sediba
      that are similar to those of early humans.

      It had long legs and the shape of it hips resembled human species better
      adapted for walking efficiently and even running than those of more
      primitive species, according to Berger.

      Its front teeth - though the shaped like those of Australopithecus - are
      small, like those of early humans, said paleontologist Fred Spoor of
      University College London.

      "The tooth size reduction that is the hallmark of Homo has always been
      associated with the increase of animal protein in the diet," said Spoor.
      "Vegetable matter requires a lot of chewing and larger tooth size so as not
      to wear through the teeth too fast."

      But Tim White of the University of California, Berkeley argued that the
      characteristics of the new species are more hype than Homo. He and Leakey
      both favor the idea that the species is more distantly related to our
      ancestors, an advanced Australopith that managed to survive until the time
      of early humans.

      White said that A. sediba is missing many of the "key characteristics" that
      are normally used to classify a species as human. Its brain, for example,
      was the size of that of the famous "Lucy" that lived hundreds of thousands
      of years earlier - tiny compared to its Homo contemporaries and less than a
      third the brain size of that of a modern human.

      He also cautioned that many of Berger's findings are based largely on the
      analysis of a single juvenile, whose proportions do not necessarily
      represent those of an adult.

      "There is obviously more media bang in a spin that relates these fossils to
      later Homo," said White.

      Everyone agrees that reaching a consensus about how close of a cousin this
      new species our will require more work. Further analysis awaits the
      newly-uncovered fossils, and the South African site promises to offer up
      more specimens of the new species.

      Devin Powell reports for Inside Science News Service.



      [Non-text portions of this message have been removed]
    • Chuck
      After ready about Sediba I got the paper and related material and there are several point worth noting. ... Their remarkably complete remains don t even add
      Message 2 of 14 , Apr 13, 2010
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        After ready about Sediba I got the paper and related material and there are
        several point worth noting.



        > The remarkably complete remains belong to a female adult and
        > a male child.

        > "Normally we have only a hip bone, a skull, a hand bone or a
        > foot bone and often we cannot even be sure what species the
        > fossils represent," said Leakey. "Here we have a collection of
        > fossils from single individuals that are exceptionally well

        > preserved and that, with further work, are likely to be even

        > more complete."



        Their "remarkably complete remains" don't even add up to even one complete
        skeleton.



        > The scientists also dated the remains by calculating the amount
        > of uranium and lead encased with them. Over time, uranium
        > breaks down into lead at a steady rate - a ticking clock that
        > revealed an age of 2 million years. The rocks that formed
        > around the bones confirm this date; they contain traces of a
        > reversal of the Earth's magnetic field that happened around
        > 1.9 million years ago.



        It turns out that the U-Pb dating was don on a flowstone deposit just below
        the fossils. Last time I checked flowstone deposition does not reset the
        radiometric clock and so it only set a maximum age. It had a reversed
        magnetic polarity but that date presupposes the accuracy of theory dynamo
        theory of the Earths magnetic field. Furthermore the sediment in which the
        fossils were actually found had a normal polarity so they dated it to just
        after that theoretical reversal. However even under their own theory the
        Earth's magnetic field would reversed four times in the past 2 million
        years so this sating is rather subjective.



        ------ Charles Creager Jr.

        Genesis Science <http://gscim.com/> Mission

        Online <http://store.gscim.com/> Store

        _____







        [Non-text portions of this message have been removed]
      • steelville
        Seems like a comedy skit. Here it is! No it isn t! I found it! No you didn t I did! over here! Over there! It s this one! We have a new winner!
        Message 3 of 14 , Apr 15, 2010
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          Seems like a comedy skit.

          "Here it is!" "No it isn't!"
          "I found it!"
          "No you didn't I did!"
          "over here!"
          "Over there!"
          "It's this one!"
          "We have a new winner!"

          It's like the Florida lottery! A new winner every week! (Usually)

          They can do a take-off on the Wendy commercial.

          "That all you got? Where's the bones?"

          --Alan


          Chuck wrote:
          >
          > After ready about Sediba I got the paper and related material and
          > there are
          > several point worth noting.
          >
          > > The remarkably complete remains belong to a female adult and
          > > a male child.
          >
          > > "Normally we have only a hip bone, a skull, a hand bone or a
          > > foot bone and often we cannot even be sure what species the
          > > fossils represent," said Leakey. "Here we have a collection of
          > > fossils from single individuals that are exceptionally well
          >
          > > preserved and that, with further work, are likely to be even
          >
          > > more complete."
          >
          > Their "remarkably complete remains" don't even add up to even one complete
          > skeleton.
          >
          > > The scientists also dated the remains by calculating the amount
          > > of uranium and lead encased with them. Over time, uranium
          > > breaks down into lead at a steady rate - a ticking clock that
          > > revealed an age of 2 million years. The rocks that formed
          > > around the bones confirm this date; they contain traces of a
          > > reversal of the Earth's magnetic field that happened around
          > > 1.9 million years ago.
          >
          > It turns out that the U-Pb dating was don on a flowstone deposit just
          > below
          > the fossils. Last time I checked flowstone deposition does not reset the
          > radiometric clock and so it only set a maximum age. It had a reversed
          > magnetic polarity but that date presupposes the accuracy of theory dynamo
          > theory of the Earths magnetic field. Furthermore the sediment in which the
          > fossils were actually found had a normal polarity so they dated it to just
          > after that theoretical reversal. However even under their own theory the
          > Earth's magnetic field would reversed four times in the past 2 million
          > years so this sating is rather subjective.
          >
          > ------ Charles Creager Jr.
          >
          > Genesis Science <http://gscim.com/ <http://gscim.com/>> Mission
          >
          > Online <http://store.gscim.com/ <http://store.gscim.com/>> Store
          >
          > _____
          >
          > [Non-text portions of this message have been removed]
          >
          >
        • Chuck
          http://www.sciencemag.org/extra/sediba/ There are links to the original papers at the above address. They are only available to registered users but you can
          Message 4 of 14 , Apr 16, 2010
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            http://www.sciencemag.org/extra/sediba/



            There are links to the original papers at the above address. They are only
            available to registered users but you can register for free.



            You can see pictures of the bones in the first paper linked to.



            Frankly their not at all impressive, basically they just dug up another dead
            ape in Africa.



            ------ Charles Creager Jr.

            Genesis Science Mission <http://gscim.com/>

            Online Store <http://store.gscim.com/>







            -----Original Message-----
            From: CreationTalk@yahoogroups.com [mailto:CreationTalk@yahoogroups.com] On
            Behalf Of steelville
            Sent: Thursday, April 15, 2010 10:54 PM
            To: CreationTalk@yahoogroups.com
            Subject: Re: [CreationTalk] One site says new missing link, this one says no



            Seems like a comedy skit.



            "Here it is!" "No it isn't!"

            "I found it!"

            "No you didn't I did!"

            "over here!"

            "Over there!"

            "It's this one!"

            "We have a new winner!"



            It's like the Florida lottery! A new winner every week! (Usually)



            They can do a take-off on the Wendy commercial.



            "That all you got? Where's the bones?"



            --Alan





            [Non-text portions of this message have been removed]
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