Story thread · 4 reports / 4 sources

Radical Study Suggests Life on Earth Arose Twice

slashdot.org · 4dShare

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.

First report: Two origins of life: Free-living cells may have emerged twice as bacteria and archaea diverged — phys.org, 6d