Life on Earth may have developed below rather than above ground, reveal scientists – Science – News – The Independent

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How life on Earth came into existence is still one of the greatest mysteries in science but new research into the “deep biosphere” indicates that the first replicating life-forms on the planet may have originated deep underground rather than, as commonly believed, on the surface.

Scientists have now discovered microbes living and reproducing as deep as 5km (3.1 miles) below ground and studies have shown that they are likely to have survived in complete isolation from the surface biosphere for millions and perhaps even billions of years.

One of the latest studies into the deep biosphere has found that these microbes form a distinct subsurface community of genetically similar individuals despite living on opposite sides of the world. This global similarity of such an isolated life-form suggests that they may have evolved directly from a common ancestor that lived as long ago at the period when life on earth originated, some 3.5 billion years ago.

An increasing number of researchers believe that life could have first got going in the tiny cracks of underground rocks, fuelled not by the energy of sunlight but by chemical fuel in the form of hydrogen and methane which can be produced in certain types of rock under high temperatures and pressures.

Written By: Steve Connor
continue to source article at independent.co.uk

4 COMMENTS

  1. @OP – Life on Earth may have developed below rather than above ground, reveal scientists

    This is a particularly poorly written article, which starts with a silly strawman title. – Nobody I am aware of suggests abiogenesis took place “above ground”. Current models suggest oceans, or hydrothermal vents, (superseding the earlier possible suggestion of shorelines) as sources.

    It then shows a picture of more recent folded sea-floor sedimentary rocks containing fossil shells.

    The interrelatedness of microbes across the planet, would suggest they were spread by ocean (or less likely atmospheric) currents.

    An increasing number of researchers believe that life could have first got going in the tiny cracks of underground rocks, fuelled not by the energy of sunlight but by chemical fuel in the form of hydrogen and methane which can be produced in certain types of rock under high temperatures and pressures.

    I don’t think there was ever any doubt, that abiogenesis pre-dated photosynthesis.

    but by chemical fuel in the form of hydrogen and methane which can be produced in certain types of rock under high temperatures and pressures.

    This sounds very like association with hydrothermal vents which is not a new concept, but the article gives minimal mention to these, – preferring to dwell on outdated views.

    The classical view of how life originated in a primordial soup came out of work carried out in 1953 by Harold Urey and Stanley Miller at Chicago University.

    These journalists really must keep up to date! The present thinking was updated from this work decades ago!

    Scientists have now discovered microbes living and reproducing as deep as 5km (3.1 miles) below ground and studies have shown that they are likely to have survived in complete isolation from the surface biosphere for millions and perhaps even billions of years.

    “Millions of years” ago is not the time life arose on Earth. They need much better dating than that to support these sorts of claims of association with abiogenesis.

    • In reply to #1 by Alan4discussion:

      @OP – Life on Earth may have developed below rather than above ground, reveal scientists

      This is a particularly poorly written article, which starts with a silly strawman title. – Nobody I am aware of suggests abiogenesis took place “above ground”. Current models suggest oceans, or hydrothermal…

      Yeah, it’s the old problem of science journalism. In order to be interesting it has to be a “revolutionary” discovery or theory. I think Neil deGrasse Tyson once mentioned how annoyed he got at the phrase “Scientists now have to go back to the drawing board.” As if we were ever anywhere but at the drawing board!

  2. The article tells us:

    “Research has shown that these underground microbes exploit a geological process known as serpentisation, when hydrogen and methane are produced as water comes into contact with the common mineral olivine under high temperatures and pressures. The microbes use the hydrogen for fuel and the methane as a source of carbon, making them completely independent of the photosynthetic microbes and plants living at the Earth’s surface.”

    This is the same bogus claim made several years ago when hydrothermal vents on the ocean floor were in the spotlight.

    Hydrogen or methane can be an energy source (used for fuel) as part of an oxidation-reduction reaction. Today’s Earth has plenty of oxygen to serve as the oxidizing agent. This oxygen comes from photosynthesis. The microbes are only “completely independent” in the minds of ignorant journalists or ignorant scientists. In the real world, the energy comes from sunlight by means of photosynthesis.

    • In reply to #3 by Chuck Johnson:
      >

      This is the same bogus claim made several years ago when hydrothermal vents on the ocean floor were in the spotlight.

      There is nothing bogus about that claim. This is a poorly written article which should also have mentioned H2S and SO2. There are plenty of examples of anaerobic life forms even on modern Earth.

      Hydrogen or methane can be an energy source (used for fuel) as part of an oxidation-reduction reaction. Today’s Earth has plenty of oxygen to serve as the oxidizing agent. This oxygen comes from photosynthesis.

      Oxygen also comes from the dissociation of H2O molecules in the upper atmosphere by solar radiation, and the loss of separated hydrogen atoms to space – as it did on pre-biotic Earth.

      “Physicists have shown that the Earth is losing about three kilograms of hydrogen gas every second. It’s about 95,000 tonnes of hydrogen that the planet is losing every year.

      There would be no free oxygen until the primordial atmospheric methane and ammonia had been oxidised. Even then there was a vast supply of dissolved iron and other oxidizable minerals in the seas from the time of the earlier reducing atmosphere.

      The microbes are only “completely independent” in the minds of ignorant journalists or ignorant scientists.

      This can easily be shown to be nonsense, with only a few clicks!

      http://en.wikipedia.org/wiki/Anaerobic-organism

      http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1489322/

      In the real world, the energy comes from sunlight by means of photosynthesis.

      Some comes from photosynthesis, some comes from sunlight without photosynthesis, and some comes from anaerobic chemical reactions. Then there is the Earth’s nuclear energy and residual geothermal heat powering some reactions!

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