Rethinking hydrothermal vents: a structural ecology perspective on the early emergence of metabolic roles

Hydrothermal vents are widely considered plausible settings for the origin of life, owing to their steep redox gradients and the availability of chemical energy. Their capacity to support organic synthesis, molecular retention, and breakdown varies with local conditions. Here, I propose a conceptual framework for assessing whether connected environments could support complementary prebiotic chemical functions. Hydrothermal systems may contribute to the breakdown and reuse of supplied organic compounds alongside their constructive roles, while ice-water interfaces may support concentration, selected synthetic reactions, and product retention when suitable reactants are available. Producer-like, consumer-like, and decomposer-like functions are used as nonexclusive analogies for chemical production, use of supplied organic compounds, and breakdown yielding potentially reusable products; they do not denote demonstrated abiotic metabolisms. The central hypothesis is that life's beginnings may have depended partly on transitions between environments, rather than on processes within any single environment alone. This proposal can be assessed by comparing coupled and isolated reaction systems for product survival, reuse, and sustained reaction activity. The article presents no new experimental validation, and neither the proposed environmental connections nor their contribution to the emergence of heritable metabolism or the last universal common ancestor is established.