sciencehabit quotes a report from Scientific Magazine: DNA is better known, but many researchers today believe that life on Earth got started with its cousin RNA, since that nucleic acid can act as both a repository of genetic information and a catalyst to speed up biochemical reactions. But those favoring this "RNA world" hypothesis have struggled for decades to explain how the molecule's four building blocks could have arisen from the simpler compounds present during our planet's early days. Now chemists have identified simple reactions that, using the raw materials on early Earth, can synthesize close cousins of all four building blocks. The resemblance isn't perfect, but it suggests scientists may be closing in on a plausible scenario for how life on Earth began. The study has been published in the journal Nature.