However, the only land exposed above sea level on Earth 3.5 billion years ago was in the form of volcanic islands, similar to the Hawaiian Islands today. The study presents a scenario by which volcanic lightning interacted with gas from the erupting volcanoes to produce small molecules. These molecules then accumulated in warm (or cool) ponds and lakes on the flanks of the volcanoes. Reactions occurred in these bodies of water over time, and possibly through wet-dry cycles. Eventually, as the islands eroded away, the molecules were released into the oceans. The researchers propose that Darwinian evolution then occurred in the oceans, resulting the biochemistry of life as we know it on Earth.

The study, “Exposed Areas Above Sea Level on Earth >3.5 Gyr Ago: Implications for Prebiotic and Primitive Biotic Chemistry,” was published in the journal Life. The work was performed at the NSF/NASA Center for Chemical Evolution (CCE) at the Georgia Institute of Technology in Atlanta, Georgia. The CCE is a collaborative program supported by the National Science Foundation (NSF) and the NASA Astrobiology Program.