Researchers have found that early Earth’s atmosphere could naturally produce sulfur-based biomolecules, including amino acids like cysteine. Using light and simple gases, they recreated conditions that created complex molecules long thought to require living organisms.

These findings suggest that life’s raw ingredients may have been widespread, not limited to rare environments like volcanic vents.

Early Atmosphere as a Source of Life’s Raw Materials
Earth’s ancient air may have played a far larger role in the rise of life than scientists once believed.

A study published today (December 1) in the Proceedings of the National Academy of Sciences, led by researchers from CU Boulder and several collaborators, reports that the early atmosphere may have been actively generating sulfur-based molecules billions of years ago. These compounds are known to be important for life.

The discovery challenges the long-standing assumption that such sulfur molecules appeared only after living organisms had already evolved.

“Our study could help us understand the evolution of life at its earliest stages,” said first author Nate Reed, a postdoctoral fellow at NASA who completed the research while working in the Department of Chemistry and the Cooperative Institute for Research in Environmental Sciences (CIRES) at CU Boulder.