Article URL: https://www.sciencealert.com/radical-study-suggests-life-on-earth-arose-from-non-living-matter-twice Comments URL: https://news.ycombinator.com/item?id=49209572 Points…

The fact that you, or I, or any living creature, is here at all is a series of astonishing strokes of luck stretching back more than 4 billion years. One of the biggest hurdles was the very first one: How did life emerge from a primordial soup of stuff that very much wasn't alive? A radical new study, published in Science Advances, suggests that this unlikely threshold may actually have been crossed not once, but twice. Two of the main lineages of life – bacteria and archaea – may have independently figured out the secrets of metabolism that upgraded them from non-living to living, according to the new study, which focused on the most rudimentary set of chemical reactions thought to enable this transformation. "The surprise is that the enzymes that catalyze those reactions are not conserved across the evolutionary divide that separates bacteria and archaea," says William Martin, a biologist at Heinrich Heine University Düsseldorf in Germany. "The new data leave only one conclusion. The bacterial and archaeal lineages made the transition to the free-living state independently. Only free-living cells are alive. "Let's call it by name: we are looking at one origin of the genetic code, but two origins of life." That's a huge claim to make, especially when defining what life even is can be surprisingly tricky.