enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Abiogenesis - Wikipedia

    en.wikipedia.org/wiki/Abiogenesis

    Subsequent research has shown possible routes of synthesis; for example, formamide produces all four ribonucleotides and other biological molecules when warmed in the presence of various terrestrial minerals. [124] [125] The RNA world hypothesis proposes that undirected polymerisation led to the emergence of ribozymes, and in turn to an RNA ...

  3. Abiogenic petroleum origin - Wikipedia

    en.wikipedia.org/wiki/Abiogenic_petroleum_origin

    There are few clear examples of abiogenic methane-ethane-butane, as the same processes favor enrichment of light isotopes in all chemical reactions, whether organic or inorganic. δ 13 C of methane overlaps that of inorganic carbonate and graphite in the crust, which are heavily depleted in 12 C, and attain this by isotopic fractionation during ...

  4. Non-planetary abiogenesis - Wikipedia

    en.wikipedia.org/wiki/Non-planetary_abiogenesis

    In chapter "Stellar Graveyards, Nucleosynthesis, and Why We Exist" of The Stars of Heaven (2001) Clifford A. Pickover discusses various forms of abiological lifes. He poses the question whether in the times of ultimate expansion of the Universe with extremely low density of matter some structures could exist that can support the life of the ...

  5. Earliest known life forms - Wikipedia

    en.wikipedia.org/wiki/Earliest_known_life_forms

    Evidence of possibly the oldest forms of life on Earth has been found in hydrothermal vent precipitates. [1]The earliest known life forms on Earth may be as old as 4.1 billion years (or Ga) according to biologically fractionated graphite inside a single zircon grain in the Jack Hills range of Australia. [2]

  6. History of research into the origin of life - Wikipedia

    en.wikipedia.org/wiki/History_of_research_into...

    Spontaneous generation, the first naturalistic theory of abiogenesis, goes back to Aristotle and ancient Greek philosophy, and continued to have support in Western scholarship until the 19th century. [15] The theory held that "lower" animals are generated by decaying organic substances.

  7. History of life - Wikipedia

    en.wikipedia.org/wiki/History_of_life

    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 ...

  8. Alternative abiogenesis scenarios - Wikipedia

    en.wikipedia.org/wiki/Alternative_abiogenesis...

    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 ...

  9. Primordial soup - Wikipedia

    en.wikipedia.org/wiki/Primordial_soup

    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.