Our cosmic origins remain plausible, not proven

‘It is mere rubbish thinking, at present, of the origin of life,’ Charles Darwin wrote to his friend Joseph Hooker in 1863. But that didn’t stop him speculating to Hooker just eight years later about a ‘warm little pond’ containing a prebiotic soup from which the first life emerged. And it hasn’t stopped us since from accumulating theories about the origin of life in almost embarrassing profusion, at a rate that far exceeds our capacity to test or eliminate any.

Among those theories, I’ve never felt very attracted by the ones that bob in Darwin’s soup, which focus on how the basic molecular ingredients of living organisms – amino acids, sugars, nucleotide bases – might have been made before life emerged. This must evidently have happened somewhere in the universe, but it leaves us a very long way from anything even close to being alive. Neither am I a fan of the obsession with making molecular systems that replicate, as if this alone crosses the threshold for life.