Headline October 29, 2016/ ''' *EARLY -][ENVIRONMENT][- EARTH* '''


- EARTH* '''

GEOLOGISTS HAVE JUST DISCOVERED in Greenland evidence for ancient life in rocks that are  *3.7 billion years old*.

The find, if confirmed-
Would make these fossils the oldest on Earth and may change scientific understanding of the origins of Life.

Experts are likely to debate whether the structures described in the new report were formed biologically or through natural processes. 
If biological, the great age of the fossils complicates the task of reconstructing  the evolution of life from the chemicals naturally present on the early Earth.

It leaves comparatively little time for evolution to have occurred and puts the process close to a time when Earth was being bombarded by destructive asteroids.

The fossils were discovered four years ago, but not publicized  while the geologists, a team led by Allen P. Nutman of the University of Wollongong in Australia, checked out their find.

''Of course one felt very excited, but we're not the running types, and we took our time,'' Dr. Nutman said. 
''We kept it secret because we wanted to present it in the most robust way we could manage.''

The fossils were part of an outcrop of ancient rock that had its usual snow cover. The rock layer forming the outcrop, known to geologists as the  *Isua supercrustal belt, lies on the southwest coast of Greenland and is some 3.9 to 3.7 billion years old.

Researchers earlier had claimed that Isua rock had a chemical composition indicative of live, but critics said this mix of chemicals could have arisen through natural processes.

The new fossils, described on Wednesday in the journal Nature, are the first visible structures found in Isua rocks. They are thought to be stromatolites,layers of sediment packed together by microbial communities living in shallow water,

They are some  230 million years more ancient than the oldest previously known fossils, also stramatolites. Those are  3.48 billion years old and were discovered in the Pilbara Craton of Western Australia.

The new report  ''provides the oldest direct evidence of microbial life,'' said Gerald Joyce, an expert on the origins of life at the  Scripps Research Institute in La Jolla, Calif.

Dr. Nautman said there was a  *diminishing probability*   that older fossils   will ever be found. Rocks from this period are very very rare 

Those that survive have been cooked to such high heats by geological processes like Mountain-forming that evidence of fossils and sedimentary layers is destroyed. Most of the  Isua  rocks have been cooked in this way.    
Only the small outcrop now discovered, measuring some 98 by 230 feet, avoided intense heating. Through this chance-escape, the little patch throws a narrow shaft of light onto events close to the dawn of life on Earth.

The rock contains several small cones, the tallest just over an inch and half. 

The cones have a layered structure that resembles the bands of sediment gathered and cemented together by the microbial communities that form today's stromatolites. 

Because of the  importance of the claim made by Dr. Nutman and his colleagues, considerable discussion can be expected before their interpretation is generally accepted.

Certain features  ''are fully credible hallmarks of microbial activity,''  Abigail C. Allwood of the  California Institute of Technology's Jet Propulsion Laboratory wrote in a commentary accompanying the article.

They have few features that make them  ''interesting and  possibly biological,'' she added in an email.

Another expert in the early Earth's environment:
Tanja Bosak of the Massachusetts Institute of Technology, said the structures do resemble modern stromatolites, but their origin  ''will be hotly debated.''

Given there is no sign of certain features that might bolster the case for biological origin, such as crinkling in the layers of sediment.

The Honour and Serving of the latest Operational Research *The oldest evidence of life on Earth* continues. Thank Ya all for reading and sharing forward. And see you on the following one.

With respectful dedication to the Scientists, Students, Professors and Teachers of advance sciences. See Ya all on !WOW!  -the World Students Society and !E-WOW!  -Ecosystem 2011:

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