Chemical evolution of life - By Oparin and Haldane

 

The origin of life by means of chemical evolution was  first explained by Russian biologist  A. I. Oparin and JBS Haldane. The oparin theory was published in 1936 in his book the origin of life. 

Oparin  and haldane proposed that the first form of life could have come from pre-existing  non living organic molecules like RNA protein etc. The formation of life takes place by a chemical evolution. This theory also states that the spontaneous generation of life under the present environmental condition is not possible. During the first billion years of its existence were radically different from the today 's condition.

At present scientists believed that the origin of life was a gradual process and life did not appear suddenly. The first condition in the origin of life was the stable condition of earth. And according to theories of life and  various geologists, about two billion years ago there were favorable conditions for the start of life.

According to oparin and Haldane  the planet was formed as a big explosion  from the mass of the sun. At that time the temperature was very high, about 5000 to 6000 degrees celsius.The carbon elements existed in the form of carbon, cyanogen and methane.

After that , the water vapor, ammonia, and methane were formed due to the reaction of protoplasmic elements in the atmosphere. 

As the earth cooled down, the molecule of water became liquified and water contained methane ammonia and minerals in the dissolved state.

Later on, due to  thundering or volcanic eruption these above molecules reacted to each other by its interaction and sugar amino acids,  protein , nucleic acids were formed by the polymerisation. Due to these polymerisation, some colloidal microscopic particles were formed in ocean water.

Oparin considered that these colloidal microscopic particles were living molecules from which the primitive organisms were developed. These primitive colloidal particles were also considered as microbes.

Some scientists believed that these microbes were like bacteria like Nitrosomonas.

The first proteinaceous structure that was formed at early primtive earth was Protobionts or coacervates.

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