====== Primordial Soup ======

>In 1953 an iconic set of experiments showed that some of the chemical building blocks of life, such as amino acids, could form spontaneously in the atmospheric conditions thought to prevail on the primordial Earth. This gave rise to the idea that the early oceans were a "primordial soup" from which life somehow emerged.\\ [...]\\ The idea still holds a great deal of water, but 50 years on the details remain sketchy. It is still unclear, for example, how a primordial soup of simple molecules could give rise to today's system of DNA and proteins. It is a classic chicken-and-egg problem: DNA codes for the proteins that catalyse the chemical reactions that replicate DNA. How could one exist before the other?"\\ \\ Source : [[http://www.newscientist.com/article/mg18324635.000-the-mysteries-of-life.html|New Scientist]] Sept. 2004

The first ideas of life having somehow formed from inanimate matter go back as far as Ancient Greece.

The original concept of //The Primordial Soup// emerged in the 1920s, suggesting that combinations of carbon, hydrogen, water vapour, and ammonia - together with electric discharges from [[content:earth_sciences:lightning|lightning]] - could form amino acids.

There are other considerations though : The same conditions which form the amino acids can also destroy them. And, as the //New Scientist// article cited above explains, the fact that amino acids can be present doesn't explain the formation of DNA and proteins.

There are currently several dozen other theories regarding how life might have evolved on Earth - //none of which has been generally accepted.//

See: [[https://en.wikipedia.org/wiki/Alternative_abiogenesis_scenarios|Wikipedia]]

An alternative theory called [[https://en.wikipedia.org/wiki/Panspermia|Panspermia]] suggests that life may have arrived on Earth via comets etc. Traces of amino acids have now been found on comets, meteorites and even in space itself ([[https://www.researchgate.net/profile/R-Boyd|example ref.]]) In 2023, it was announced that //uracil// - one of the base-pair componds of RNA - had been found in a meteorite ([[https://www.nature.com/articles/s41467-023-36904-3|ref.]]).

Nevertheless, the problem still remains as to how life arose, regardless of where it happened.

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Also see : [[content:life_sciences:life_itself:life_on_earth]] and [[content:life_sciences:life_itself:life-definition]]

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