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Oparin and Haldane suggested that the atmosphere of the early Earth may have been chemically reducing in nature, composed primarily of methane (CH 4), ammonia (NH 3), water (H 2 O), hydrogen sulfide (H 2 S), carbon dioxide (CO 2) or carbon monoxide (CO), and phosphate (PO 4 3−), with molecular oxygen (O 2) and ozone (O 3) either rare or absent.
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.
The history of life on Earth traces the processes by which living and extinct organisms evolved, from the earliest emergence of life to the present day. Earth formed about 4.5 billion years ago (abbreviated as Ga, for gigaannum) and evidence suggests that life emerged prior to 3.7 Ga. [1] [2] [3] The similarities among all known present-day species indicate that they have diverged through the ...
Primordial soup, also known as prebiotic soup and Haldane 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.
[2] [3] Such ideas have something in common with the modern hypothesis of the origin of life, which asserts that life emerged some four billion years ago from non-living materials, over a time span of millions of years, and subsequently diversified into all the forms that now exist. [4] [5]
The LUCA probably existed at latest 3.6 billion years ago, and possibly as early as 4.3 billion years ago [2] or earlier. The nature of this point or stage of divergence remains a topic of research. All earlier forms of life preceding this divergence and all extant organisms are generally thought to share common ancestry. On the basis of a ...
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Theories of the origin of humans. Add languages. ... Download QR code; Print/export Download as PDF; Printable version; Appearance. move to sidebar hide.