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If the deep marine hydrothermal setting was the site for the origin of life, then abiogenesis could have happened as early as 4.0-4.2 Gya. If life evolved in the ocean at depths of more than ten meters, it would have been shielded both from impacts and the then high levels of ultraviolet radiation from the sun.
In 1929, Haldane introduced the modern concept of abiogenesis in an eight-page article entitled "The Origin of Life" in The Rationalist Annual, [86] describing the primitive ocean as a "vast chemical laboratory" containing a mixture of inorganic compounds – like a "hot dilute soup" in which organic compounds could have formed.
Primordial soup, also known as prebiotic soup, is the hypothetical set of conditions present on the Earth around 3.7 to 4.0 billion years ago. It is an aspect of the heterotrophic theory (also known as the Oparin–Haldane hypothesis) concerning the origin of life, first proposed by Alexander Oparin in 1924, and J. B. S. Haldane in 1929.
This suggests that methanogenesis in the presence of serpentinites is restricted in space and time to mid-ocean ridges and upper levels of subduction zones. However, water has been found as deep as 12,000 metres (39,000 ft), [ 38 ] so water-based reactions are dependent upon the local conditions.
A scenario is a set of related concepts pertinent to the origin of life (abiogenesis), such as the iron-sulfur world. Many alternative abiogenesis scenarios have been proposed by scientists in a variety of fields from the 1950s onwards in an attempt to explain how the complex mechanisms of life could have come into existence. These include ...
The sea surface microlayer (SML) at the air-sea interface is a distinct, under-studied habitat compared to the subsurface and copepods, important components of ocean food webs, have developed key adaptations to exploit this niche. [40] The ocean-spanning SML forms the boundary between the atmosphere and the hydrosphere.
Abiotic factors in ocean environments also include aerial exposure, substrate, water clarity, solar energy and tides. [5] Consider the differences in the mechanics of C3 , C4 , and CAM plants in regulating the influx of carbon dioxide to the Calvin-Benson Cycle in relation to their abiotic stressors.
Scientists as far back as John Desmond Bernal in the late 1940s thus speculated that clay surfaces would play a large role in abiogenesis, as they might concentrate monomers. [87] Several such models for mineral-mediated polymerization have emerged, such as the interlayers of layered double hydroxides like green rust over wet-dry cycles. [ 88 ]