Life on Earth may have begun from non-living matter on two separate occasions, according to a radical study highlighted by ScienceAlert. The idea challenges the assumption that all living things trace back to one unique emergence event.

The origin of life remains one of science’s biggest questions. More than four billion years ago, Earth contained the raw ingredients associated with a primordial environment, but explaining how those materials became living systems is a major scientific hurdle.

If life arose independently twice, it could change how researchers think about the earliest chapters of Earth’s history and the likelihood of life emerging under suitable conditions. The proposal remains a striking interpretation of a problem that scientists continue to investigate.