THEorigin of the first forms of lifeit is a question that has puzzled humanity for a long time. Several theories have emerged to try to explain the emergence of organisms, but none has been 100% accepted by scientists.
One of these theories that try to explain the origin of life is the one proposed by biologist John Burdon S. Haldane (1892-1964) and by the biochemist Aleksandr I. Oparin (1894-1980) in the 1920s. According to these authors, the origin of life is the result of a chemical evolution.
→ The theory of Oparin and Haldane
The theory proposed by Oparin and Haldane, independently, said that simple organic molecules such as amino acids, sugars and nitrogenous bases, were formed from inorganic compounds that formed agreed. Complex structures formed until life emerged.
According to these authors, about 2.5 billion years ago, the Earth began to cool and rocks were being formed. During this period, the atmosphere was basically composed of ammonia, methane, hydrogen and water vapor. This steam began to condense, giving rise to the water cycle, with the formation of rain.
During this period there were also many electrical discharges, which acted on the molecules present in the atmosphere. In addition to the discharges, ultraviolet radiation also acted on these molecules. The action of these two factors caused the emergence of new molecules, such as the amino acids, which are the protein-forming units.
Over time, seas, lakes and lakes were formed, which began to accumulate the organic compounds that were formed. In these environments, structures called coacervate, that is, a cluster of protein molecules. These structures developed the ability to duplicate themselves, that is, to form other individuals. Then, the first living beings appeared.
Therefore, we can divide this theory, which became known as coacervate theory, into three main points:
1- Formation of organic molecules;
2- Formation of coacervates;
3- Evolution to organisms capable of reproducing.
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