RNA nucleosides built in one prebiotic pot

Origins-of-life research models integrate the synthesis of RNA building blocks For decades, the RNA world has been one of the most influential hypotheses regarding the origins of life on Earth. In this hypothetical era before the emergence of DNA and proteins, “life” on primordial Earth consisted of RNA molecules that both store genetic information and catalyze self-replication reactions ( 1 ). Despite its popularity with researchers, the RNA world hypothesis has suffered from its own origins conundrum: A mechanism for the simultaneous prebiotic synthesis of RNA nucleosides from both the purine and pyrimidine families has long eluded scientists ( 2 ). Although disparate prebiotic syntheses have been demonstrated for the two classes of RNA nucleosides ( 3 , 4 ), no single geochemical scenario has generated both. Now, on page 76 of this issue, Becker et al. ( 5 ) report on chemistry that accomplishes this long-awaited goal.