Concomitant formation of protocells and prebiotic compounds under a plausible early Earth atmosphere

Abstract

Miller–Urey experiments demonstrated that prebiotic organic compounds can be synthesized from a reducing atmosphere, alkaline water, and electrical discharges. We show that in these experiments, only in the presence of water, silica induces the formation of a solid organic film made of polymers of hydrogen cyanide. In these films, we found nano- to micron-size biomorphic protocells forming through a mechanism of bubbling and water–gas interfacial precipitation. Our results suggest that protocells and the key molecules of life already coexisted on the earliest Earth, setting stage for the emergence of life and additional criteria for life detection. These organic “protoworlds” could be widely distributed across the universe on any Earth-like body where they might follow different evolutionary paths.