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World's Oldest Known Fossil

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  • World's Oldest Known Fossil

    Source: http://www.upi.com/Science_News/2017/03/01/Paleontologists-find-worlds-oldest-fossil/9941488397598/



    Paleontologists find world's oldest fossil

    "This discovery helps us piece together the history of our planet and the remarkable life on it, and will help to identify traces of life elsewhere in the universe," said study leader Dominic Papineau.

    March 1 (UPI) -- Scientists have discovered the world's oldest fossil, the remains of a microorganism that lived between 3.7 billion and 4.3 billion years ago. Earth itself is believed to have formed just 4.5 billion years ago.

    The signature of the iron-eating bacteria -- its tiny filaments and tubes -- was found encased in a piece of quartz excavated from the Nuvvuagittuq Supracrustal Belt in Quebec, Canada.

    "Our discovery supports the idea that life emerged from hot, seafloor vents shortly after planet Earth formed," Matthew Dodd, a PhD student at University College London, said in a news release. "This speedy appearance of life on Earth fits with other evidence of recently discovered 3,700 million year old sedimentary mounds that were shaped by microorganisms."

    Prior to the latest discovery, the oldest known microfossil was a fragment of mineralized bacteria found in Western Australia and dated at 3.4 billion years old. But some scientists suggested the fossil was a non-biological anomaly in the rock.

    © Copyright Original Source

    Glendower: I can call spirits from the vasty deep.
    Hotspur: Why, so can I, or so can any man;
    But will they come when you do call for them? Shakespeare’s Henry IV, Part 1, Act III:

    go with the flow the river knows . . .

    Frank

    I do not know, therefore everything is in pencil.

  • #2
    ECREE!!! We already knew where the world's oldest fossil was. Right here! Mossy hasn't gone anywhere!

    Comment


    • #3
      The important implications of this discovery are: (1) The hypothesis that abiogenesis took place in hot vents in the ocean, likely in the mid ocean ridgeshave gained more acceptance. (2) The very early appearance of life on earth demonstrates that life likely formed quickly when conditions were favorable very early in earth's history. This indicates the dice are loaded to form life when conditions are right.
      Glendower: I can call spirits from the vasty deep.
      Hotspur: Why, so can I, or so can any man;
      But will they come when you do call for them? Shakespeare’s Henry IV, Part 1, Act III:

      go with the flow the river knows . . .

      Frank

      I do not know, therefore everything is in pencil.

      Comment


      • #4
        Originally posted by shunyadragon View Post
        The important implications of this discovery are: (1) The hypothesis that abiogenesis took place in hot vents in the ocean, likely in the mid ocean ridgeshave gained more acceptance. (2) The very early appearance of life on earth demonstrates that life likely formed quickly when conditions were favorable very early in earth's history. This indicates the dice are loaded to form life when conditions are right.
        Sounds very interesting. It would be nice if we could reproduce those conditions some day, with all the right ingredients, and see if we can coax something to happen.
        Middle-of-the-road swing voter. Feel free to sway my opinion.

        Comment


        • #5
          Originally posted by Yttrium View Post
          Sounds very interesting. It would be nice if we could reproduce those conditions some day, with all the right ingredients, and see if we can coax something to happen.
          Actually that is the direction of current research:

          Source: http://www.nature.com/articles/nmicrobiol2016116



          The physiology and habitat of the last universal common ancestor
          Madeline C. Weiss, Filipa L. Sousa, Natalia Mrnjavac, Sinje Neukirchen, Mayo Roettger, Shijulal Nelson-Sathi & William F. Martin

          The concept of a last universal common ancestor of all cells (LUCA, or the progenote) is central to the study of early evolution and life's origin, yet information about how and where LUCA lived is lacking. We investigated all clusters and phylogenetic trees for 6.1 million protein coding genes from sequenced prokaryotic genomes in order to reconstruct the microbial ecology of LUCA. Among 286,514 protein clusters, we identified 355 protein families (∼0.1%) that trace to LUCA by phylogenetic criteria. Because these proteins are not universally distributed, they can shed light on LUCA's physiology. Their functions, properties and prosthetic groups depict LUCA as anaerobic, CO2-fixing, H2-dependent with a Wood–Ljungdahl pathway, N2-fixing and thermophilic. LUCA's biochemistry was replete with FeS clusters and radical reaction mechanisms. Its cofactors reveal dependence upon transition metals, flavins, S-adenosyl methionine, coenzyme A, ferredoxin, molybdopterin, corrins and selenium. Its genetic code required nucleoside modifications and S-adenosyl methionine-dependent methylations. The 355 phylogenies identify clostridia and methanogens, whose modern lifestyles resemble that of LUCA, as basal among their respective domains. LUCA inhabited a geochemically active environment rich in H2, CO2 and iron. The data support the theory of an autotrophic origin of life involving the Wood–Ljungdahl pathway in a hydrothermal setting.

          The last universal common ancestor (LUCA) is an inferred evolutionary intermediate1 that links the abiotic phase of Earth's history with the first traces of microbial life in rocks that are 3.8–3.5 billion years of age2. Although LUCA was long considered the common ancestor of bacteria, archaea and eukaryotes3,4, newer two-domain trees of life have eukaryotes arising from prokaryotes5,6, making LUCA the common ancestor of bacteria and archaea. Previous genomic investigations of LUCA's gene content have focused on genes that are universally present across genomes4,7,8, revealing that LUCA had 30–100 proteins for ribosomes and translation. In principle, genes present in one archaeon and one bacterium might trace to LUCA, although their phylogenetic distribution could also be the result of post-LUCA gene origin and interdomain lateral gene transfer (LGT)8, given that thousands of such gene transfers between prokaryotic domains have been detected9.

          To identify genes that can illuminate the biology of LUCA, we took a phylogenetic approach. Among proteins encoded in sequenced prokaryotic genomes, we sought those that fulfil two simple criteria: (1) the protein should be present in at least two higher taxa of bacteria and archaea, respectively, and (2) its tree should recover bacterial and archaeal monophyly (Fig. 1). Genes meeting both criteria are unlikely to have undergone transdomain LGT, and thus were probably present in LUCA and inherited within domains since the time of LUCA. By focusing on phylogeny rather than universal gene presence, we can identify genes involved in LUCA's physiology—the ways that cells access carbon, energy and nutrients from the environment for growth.

          © Copyright Original Source



          The fortunate very rare luck of finding this fossil is amplified by the fact that seafloor vents and ocean sea floor spreading zones are very temporal on the landscape of the history of continental drift.
          Glendower: I can call spirits from the vasty deep.
          Hotspur: Why, so can I, or so can any man;
          But will they come when you do call for them? Shakespeare’s Henry IV, Part 1, Act III:

          go with the flow the river knows . . .

          Frank

          I do not know, therefore everything is in pencil.

          Comment


          • #6
            Another ancient fossil has been discovered supporting the theory that the first life began and evolved around hot springs. It is not as old as the previous found, but it is significant as a different type of fossil microbial fossil.

            Source: http://www.sci-news.com/paleontology/earliest-signs-microbial-life-land-04847.html



            Earliest Signs of Microbial Life on Land Found in 3.48-Billion-Year-Old Hot Spring Deposits
            May 10, 2017 by News Staff / Source

            Fossil evidence of early microbial life has been found in ancient hot spring deposits in the Dresser Formation in the Pilbara Craton, Western Australia, that date back approximately 3.48 billion years. A paper reporting this discovery is published in the journal Nature Communications.

            Spherical bubbles preserved in 3.48 billion-year-old hot spring deposits in the Dresser Formation provide evidence for early microbial life having lived on land. Image credit: University of New South Wales.
            Spherical bubbles preserved in 3.48 billion-year-old hot spring deposits in the Dresser Formation provide evidence for early microbial life having lived on land. Image credit: University of New South Wales.
            Paleontologists are considering two hypotheses regarding the origin of life. Either that it began in deep sea hydrothermal vents, or alternatively that it began on land in a version of Charles Darwin’s ‘warm little pond.’

            “The discovery of potential biological signatures in ancient hot springs in Western Australia provides a geological perspective that may lend weight to a land-based origin of life,” said lead author Tara Djokic, a Ph.D. candidate at the University of New South Wales.

            “Our research also has major implications for the search for life on Mars, because the Red Planet has ancient hot spring deposits of a similar age to the Dresser Formation.”

            Previously, the world’s oldest evidence for microbial life on land came from 2.7- 2.9 billion-year-old deposits in South Africa containing organic matter-rich ancient soils.

            “Our exciting findings don’t just extend back the record of life living in hot springs by 3 billion years, they indicate that life was inhabiting the land much earlier than previously thought, by up to about 580 million years,” Djokic said.

            Djokic and her colleagues from the Universities of Auckland and New South Wales studied exceptionally well-preserved deposits which are 3.48 billion years old in the Dresser Formation.

            © Copyright Original Source

            Glendower: I can call spirits from the vasty deep.
            Hotspur: Why, so can I, or so can any man;
            But will they come when you do call for them? Shakespeare’s Henry IV, Part 1, Act III:

            go with the flow the river knows . . .

            Frank

            I do not know, therefore everything is in pencil.

            Comment


            • #7
              hr.jpg
              When I Survey....

              Comment


              • #8
                Originally posted by Faber View Post
                [ATTACH=CONFIG]22302[/ATTACH]
                Glendower: I can call spirits from the vasty deep.
                Hotspur: Why, so can I, or so can any man;
                But will they come when you do call for them? Shakespeare’s Henry IV, Part 1, Act III:

                go with the flow the river knows . . .

                Frank

                I do not know, therefore everything is in pencil.

                Comment


                • #9
                  Part of the argument for the first life forming around hot springs in the up welling of ocean ridges is that the earth is about 4.5 billion years old by the evidence, the first continents formed about 3.7 billion years ago or earlier based on oldest continental crust found in western Greenland, and ancient zircon crystals. The oldest known life is at present is ~ 3.7 million years old found in rocks formed by hot springs at up welling zones of what we describe as mid ocean ridges.

                  The up welling zones began to occur as the cyclic currents under the new volcanic crust began to push up the underlyining material in up weling zones corresponding to subduction zones where the first continental lighter material oozed up from the material being subducted.
                  Last edited by shunyadragon; 05-14-2017, 07:37 PM.
                  Glendower: I can call spirits from the vasty deep.
                  Hotspur: Why, so can I, or so can any man;
                  But will they come when you do call for them? Shakespeare’s Henry IV, Part 1, Act III:

                  go with the flow the river knows . . .

                  Frank

                  I do not know, therefore everything is in pencil.

                  Comment

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