From prebiotic soup to fine-grained RNA world

‘It is mere rubbish thinking, at present, of origin of life’, Charles Darwin famously wrote in 1863 to his friend Joseph Hooker. Equally memorably, a mere eight years later he could not refrain from doing so anyway, writing to Hooker again that if there had been ‘some warm little pond with all sort of ammonia and phosphoric salts,—light, heat, electricity present’, then it was possible that ‘a protein compound was chemically formed, ready to undergo still more complex changes’ – leading to the first life-forms.

Darwin’s notion of a prebiotic soup seasoned with the right chemical ingredients was later developed in speculations by Alexander Oparin and J B S Haldane, and then tested experimentally in the ground-breaking experiments of Stanley Miller and Harold Urey in 1952. These produced simple amino acids from a mixture of methane, ammonia, hydrogen and water energised with electrical discharges. But while countless lab studies of plausible prebiotic chemistry have been conducted since, the tale has only grown ever more complicated as we come to understand more about the actual geochemical and geological conditions on the early Earth.