Abiogenesis

Abiogenesis (Greek a-bio-genesis, "non biological origins") is, in its most general sense, the hypothetical generation of life from non-living matter. Today the term is primarily used to refer to hypotheses of the origin of life from a primordial soup. Earlier notions of abiogenesis, now more commonly known as spontaneous generation, held that living organisms are generated by decaying organic substances, e.g. that mice spontaneously appear in stored grain or maggots spontaneously appear in meat. (That idea, which has long been known to be incorrect, will be called "Aristotelian abiogenesis" in this article.)

Modern concept of abiogenesis

Main article: Origin of life

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Even as Aristotelian abiogenesis was being disproven, many scientists, such as T. H. Huxley, continued to postulate a "primordial archebiosis", in which the living organisms observed in the present world had originally arisen in a series of stages from non-living matter. (This hypothetical scenario is not greatly different from the original Aristotelian hypothesis). Such scientists pointed out that the disproof of Aristotelian abiogenesis applied only to "known existing organisms", not to unknown forms of life or proto-life which may have existed under the vastly different conditions of the early Earth. This does not take into account the proposed impossibility of complex organisms developing from less complex forms (irreducible complexity).

Related Topics:
T. H. Huxley - Irreducible complexity

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The modern definition of abiogenesis is concerned with the formation of the earliest forms of life on earth from primordial chemicals. This is a significantly different thing from the concept of Aristotelian abiogenesis, which postulated the formation of complex organisms. Different hypotheses for modern abiogenetic processes are currently under debate with no clear frontrunner; see, for example, RNA world hypothesis, proteinoid, Miller experiment.

Related Topics:
RNA world hypothesis - Proteinoid - Miller experiment

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