One hypothesis is that the iron sulphide spewing from deep-sea volcanic vents precipitated into a solid mass with lots of tiny chambers where simple biological molecules could become concentrated and assemble, using energy from iron redox reactions.
The ‘panspermia hypothesis’, on the other hand, suggests that living cells or spores may have arrived fully formed travelling on comets from outer space. Recent research by Prof John Sutherland at Cambridge University offers a possible compromise between the two: comet impacts may have delivered hydrogen cyanide, which reacted with the hydrogen sulphide already on Earth to form the earliest building block molecules. That then assembled to form RNA.
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