How life originated on Earth continues to fascinate scientists, but it's not easy peering back billions of years into the past. Now, evidence is growing for a relatively new hypothesis of how life began: with a very precise mix of RNA and DNA.
RNA and DNA both determine the genetic make-up of all biological life, with DNA acting as a genetic blueprint and RNA as a blueprint reader or decoder. For a long time, it was thought that RNA developed on Earth first, with DNA evolving afterwards – but mounting evidence suggests they may have emerged at the same time and both been involved in kickstarting life on the planet.