Marine snow is typically understood as a biological phenomenon in modern oceans, consisting of aggregates of organic matter and microorganisms. However, the fundamental physicochemical processes underlying particle aggregation, adsorption, and transport are not inherently biological. Here, we propose that marine snow–like aggregates, formed from mineral colloids and prebiotic organic compounds, may have acted as mobile interfacial carriers in early Earth environments. Such aggregates could concentrate, transport, and redistribute prebiotic molecules across spatially distinct niches, linking sites of molecular accumulation—such as ice–water interfaces—with sites of transformation and energy availability, including hydrothermal systems. By providing dynamic interfaces that undergo repeated aggregation and dispersion, these structures may have facilitated molecular exchange and recombination processes that are otherwise unlikely in dilute aqueous environments. This hypothesis reframes marine snow as a physicochemical mechanism for spatial integration in prebiotic chemistry and suggests testable implications for the role of colloidal transport in the origin of life.
S. Kato (Wed,) studied this question.