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The origin of life.

posted Jan 30, 2015, 12:00 AM by Ranmini Perera   [ updated Jul 19, 2016, 10:26 PM by Upali Salpadoru ]









 Fig.1 Alvin's manipulator reaches toward a black smoker chimney seen through the view port.
"A popular theory today is that the life originated in the ‘black smokers’. "

The “Theory of evolution” is a story without a beginning. 
But day by day, year after year, since the publication of the book . “Origin of Species” in 1859,  evidence has  been gathering  reinforcing the theory.  
Until a few years ago , it was the general belief, that the beginning would be for ever remain hidden. Charles Darwin and his supporters anticipated greatest support from palaeontology. (study of fossils) As the early life forms would have been soft bodied, nobody expected to get any  fossilized  remains or even a trace of them.

Courtsey:- Oceanus mag  Woods hole oceaniographic institution.

The discovery and analysis of Stromatolites formed in shallow water by the adhering of earliest life forms to rocks has changed the picture. “Some of the first forms of life on Earth are recorded in stromatolites in rocks 3.5 billion years old. These continue to form most abundantly in Shark Bay in  Australia. They provide the most ancient records of life on Earth by fossil remains.” -The online dictionary-.
 

Fig.2 Stramatolites are the oldest fossils...... Virtual fossil library.....


Although the discovery of stromatolites  has proved the existence of life in the pre archaic era, it has not revealed the transformation of inorganic to organic matter.  Darwin was of opinion that life began in hot water  containing the elements such as  Hydrogen, Nitrogen, Carbon, Phosphorus  and Sulphur exposed to volcanic eruptions, meteoric showers, lightening and UV rays. This is ‘spontaneous generation of life’ which was opposed by Louis Pasteur Fr. (1822 – 1896).

In 1824, the Russian  biologist, Alexander Oparin proposed that the  "spontaneous generation of life" would have occurred at least once. He gave two reasons to explain why it cannot occur now.  Firstly the conditions on the earth have  undergone a reversal.  Earlier it was a very harsh and violent earth with a ‘reducing’ atmosphere. (Oxygen less). The other was that if a new organism were to be generated spontaneously the established organisms prevalent today would devour it.


The eminent  English biologist J.B.S. Haldane suggested that the change from inorganic to organic would have taken place in the ‘premodial soup’ existed in the oceans at the time. The famous Professor in  X’ ray crystallography,  J.D. Bernal strongly supported this.In 1952

Prof. Harold Urey devised a laboratory test  to find out what happened with the ‘primordial soup’  3 to 4 billion  years ago. Stanley Miller, his graduate student , successfully carried out this experiment. A mixture of water, methane and ammonia was exposed in a closed system, to electric sparks continuously for a few days. In a day the colourless water became pink. After a week it was brown. At the end, on analysis Miller found a number of organic compounds  including 5 of the amino acids, which are the monomers of protein, with which our bodies are made of.
After Miller’s death, a recent analysis of preserved distillates , has disclosed the presence of over 20 amino acids.  


A popular theory today is that the life originated in the ‘black smokers’.   “a vent in a geologically active region of the sea floor from which issues superheated water laden with minerals (as sulphide precipitates); also :  a rock chimney covering such a vent” ......Merriam Webster online dictionary.....  Under these extremely hostile conditions, life has been discovered. These  unlike all other life forms that we know of, do not depend on the energy from the sun. Their food consist of sulphur, iron and other inorganic matter.  It is now assumed that they form the wide base of all food chains. So many scientist believe that these were the pioneer living creatures.


“NASA sponsored experiments in 1996, designed to test organic synthesis in ‘black smokers’, where high temperature and pressure prevail, simple gases were subjected to chemically reactive minerals. It has been proved beyond doubt  that volcanic gases can readily react with rocks and sea water to make all of the life’s building blocks.” ............The story of Earth by R M Hazan...........


 Svante Arrhenius Swedish Noble Laureate chemist   in 1903 published The Distribution of Life in Space,  According to him living forms such as bacterial spores travel astronomical distances propelled by radiation energy and start living when they find a proper habitat. At the time it was considered as science fiction. This hypothesis is now known as radio-panspermia.

English Astronomer Sir Fred Hoyle (1915 – 2001) and  Sri Lankan Sri Lankan born astrophysicist Chandra Wickremasinghe , are two stalwarts supporting Panspermia. Fred Hoyle not only supported panspermia but vehemently opposed any form of  abiogenesis’. According to him the chance of occurring this is one in 1040,000. This is many times greater than the number of atoms in the world which is only 1080. 


As evidence they cite the ability of microbial spores to lie dormant for many years embedded in rocks getting exposed to heat and radiation. Chemical analysis of  Carbon rich meteorites have shown the presence of many organic compounds which can become building blocks of living things..  Murchison meteorite that crashed in Australia over 40 years ago is one of them. “Prof. Philippe Kopplin from the Institute for Ecological Chemistry in Neuherberg, Germany and his colleagues examined the .. meteorite ……….and found.. more than 14,000 different elementary compositions, including 70 amino acids .”...... Universe Today.


Another example is the meteorite that fell to earth  in Polonnaruwa on Dec.29,2012. “The team, led by Jamie Wallis of Cardiff University and , director of the Buckingham Center for Astrobiology, says that electron microscope images depict what look to be microscopic diatoms, a form of algae,.” ...........NPR  The two way.......  There is no universal agreement on this as many experts believe that the samples may have been contaminated.


Fig.3Muchison meteorite.

Strictly speaking, panspermia does not address the origin of life, they just throw the ball into another court.  According to them life originated some where in the milky way and  came to the earth via cosmic debry. But how it began anywhere they don’t have an answer.


Hurdle number one has been cleared.  There is no dispute with regard to the formation of organic basic units of life.  This synthesis has been proved beyond reasonable doubt. Next hurdle is to show the assembling of molecules capable of memory and the ability to replicate. This probably would be achieved in a couple of decades.

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