Life on Earth

There are two different theories on the origin of life on Earth: the autotrophy theory and the heterotrophy one. The first theory assumes that the first living being was autotrophic , meaning that it is able to produce organic substances from inorganic ones like green plants do, through a complex reaction called “chlorophyll photosynthesis”. In the second case instead, the first living organism would have been heterotrophic, meaning that it was not able to produce its own food, but had to feed on other living beings. In fact, animals (heterotrophic) need to eat plants (autotrophic) to survive, while the latter have no such need.
In the 1920s the English biologist John Burdon Sanderson Haldane (1892 – 1964) , considering that at the time the environment on Earth was very different from what it is today, began to draw up his own conclusions. Initially on the primitive Earth there was no life as there is today.
According to Haldane if organic matter formed nowadays, it would be immediately eliminated by some living organism , while at the time, in the total absence of any microorganisms that could decompose it, would have had plenty of time to develop and become more complex.
In 1924 the soviet researcher Aleksandr Ivanovic Oparin came forth with theories which were similar to Haldane’s one, but with the difference that according to the first, the primitive atmosphere had to be rich in hydrogen, while according to the English scientist, it was rich in carbon dioxide. To have experimental proof of this new theory we shall start from this last supposition.
Oparin and Haldane approached the argument from a scientific point of view omitting any religious interference and this obviously wasn’t accepted by the faithful that instead were trying to prove that life couldn’t have sprung forth from the random encounters between atoms, but was an act of God. Actually, proteins are extremely complex molecules, that cannot have formed from random encounters between hydrogen, carbon, oxygen and nitrogen atoms, but it has been scientifically proved that the possible combinations of simpler molecules are ruled by physical and chemical laws therefore they are limited and not random.

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