Quantifying Catalysis at the Origin of Life.

The construction of hypothetical environments to produce organic molecules such as metabolic intermediates or amino acids is the subject of ongoing research into the emergence of life. Experiments specifically focused on an anabolic approach typically rely on a mineral catalyst to facilitate the supply of organics that may have produced prebiotic building blocks for life. Alternatively to a true catalytic system, a mineral could be sacrificially oxidized in the production of organics, necessitating the emergent 'life' to turn to virgin materials for each iteration of metabolic processes. The aim of this perspective is to view the current 'metabolism-first' literature through the lens of materials chemistry to evaluate the need for higher catalytic activity and materials analyses. While many elegant studies have detailed the production of chemical building blocks under geologically plausible and biologically relevant conditions, few appear to do so with sub-stoichiometric amounts of metals or minerals. Moving toward sub-stoichiometric metals with rigorous materials analyses is necessary to demonstrate the viability of an elusive cornerstone of the 'metabolism-first' hypotheses: catalysis. We emphasize that future work should aim to demonstrate decreased catalyst loading, increased productivity, and/or rigorous materials analyses for evidence of true catalysis.