According to researchers, primitive shallow water bodies such as ponds might have provided appropriate conditions for the infusion of first life forms on Earth. Due to the less capacity, concentrations of key molecules that are essential in evolving life were higher in ponds.
Nitrogen is one of the key molecules found in all the life forms and this element could be present in the form of nitrogenous oxides in the ponds, where the possibility of accumulation of the compounds is high enough to react with other compounds and led to the production of complex biomolecules. However, in oceans, due to higher dilution and hence lower concentration of nitrogenous compounds, the possibility of accumulation and reaction with other compounds to pursue life-catalyzing reaction was quite low.
The research findings are recently published in the journal Geochemistry, Geophysics, Geosystems.
Two key hypothetical reactions considered by the scientists might have occurred, which played a crucial role in evolving life. In the first case, nitrogenous oxides present in deep oceans could have reacted with CO2 bubbles evolved from hydrothermal vents under the sea to generate molecular building blocks for living organisms. In the second case, RNA—the hereditary information carrier—could have evolved for the origin of life. When the primitive free-floating RNA molecule came into the contact with nitrogenous oxides, RNA could have been chemically stimulated to begin the primary molecular chains of life.
The formation of nitrogenous oxides from atmospheric nitrogen requires extremely high energy for the breakdown of nitrogen molecules. During the primitive era, this reaction could be carried out by lightning. This led to the formation of nitrogenous oxides, which were likely deposited in water bodies such as ponds and oceans.
However, based on the recent study, nitrogenous compounds in the oceans could be converted back into the atmospheric nitrogen by the ultraviolet radiations and the dissolved iron. Therefore, there are greater chances of the evolution of life from ponds rather than seas and oceans.
