SUMMARYA study published in Science Advances argues that bacteria and archaea may have independently transitioned from nonliving chemistry to free-living life on Earth. The analysis focused on the most basic metabolic reactions and found that the enzymes behind them are not conserved across the two lineages. The researchers conclude this could mean life arose twice, while the genetic code had a single origin.
A new study argues that life may have emerged twice on Earth. "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," reports ScienceAlert, citing a new study that "focused on the most rudimentary set of chemical reactions thought to enable this transformation." From the report: "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 Dusseldorf 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. The findings have been published in the journal Science Advances.