Abiogenesis

Abiogenesis (Brit.: /ˌeɪˌbaɪoʊˈdʒɛnᵻsᵻs, -ˌbaɪə-, -ˌbiːoʊ-, -ˌbiːə-/AY-by-oh-JEN-ə-siss or AY-bee-oh-JEN-ə-siss) or biopoiesis or OoL (Origins of Life), is the natural process of life arising from non-living matter, such as simple organic compounds. It is thought to have occurred on Earth between 3.8 and 4.1 billion years ago, and is studied through a combination of laboratory experiments and extrapolation from the genetic information of modern organisms in order to make reasonable conjectures about what pre-life chemical reactions may have given rise to a living system.

The study of abiogenesis involves three main types of considerations: the geophysical, the chemical, and the biological, with more recent approaches attempting a synthesis of all three. Many approaches investigate how self-replicating molecules, or their components, came into existence. It is generally accepted that current life on Earth descended from an RNA world, although RNA-based life may not have been the first life to have existed. The Miller–Urey experiment and similar experiments demonstrated that most amino acids, basic chemicals of life, can be synthesized from inorganic compounds in conditions intended to be similar to early Earth. Several mechanisms of organic molecule synthesis have been investigated, including lightning and radiation. Other approaches ("metabolism first" hypotheses) focus on understanding how catalysis in chemical systems on the early Earth might have provided the precursor molecules necessary for self-replication. Complex organic molecules have been found in the Solar System and in interstellar space, and these molecules may have provided starting material for the development of life on Earth.