Why ‘RNA world’ theory on origin of life may be wrong after all

                      

Evidence for the RNA world is looking a bit muddier (Image: Frans Lanting/Getty)
WITHIN every living cell lurks a relic from the earliest stages of life on Earth, like a flint spear point in a modern military arsenal. Its discovery is overturning our understanding of how we came to be – and could signal the end of the favoured explanation of the origin of life, “RNA world”.
Life has a chicken-and-egg problem: enzymes are needed to make nucleic acids – the genetic material – but to build them you need the genetic information contained in nucleic acids. So most researchers assume that the earliest life, long before the evolution of cells, consisted of RNA molecules. These contain genetic information but can also fold into complex shapes, so could serve as enzymes to help make more RNA in their own image – enabling Darwinian ...