Lightning, Minerals, and the Iron Bottleneck: A Probabilistic Geochemical Framework for Early Abiogenesis Environments V8

Understanding how life emerged from non-living chemistry remains one of the central challenges in science. This study develops a probabilistic and geochemical framework to quantify the likelihood of abiogenesis under early Earth conditions, explicitly linking environmental opportunity with chemical feasibility. Multiple environments have been proposed as plausible settings for abiogenesis, including oceans, hydrothermal systems, and surface environments. Each offers distinct advantages but also faces constraints related to concentration, energy availability, and reaction stability. Rather than favoring a single exclusive scenario, we introduce a quantitative approach that enables comparative evaluation across different prebiotic environments. Within this framework, shallow, mineral-rich surface ponds are examined as environments in which episodic wet--dry cycling, evaporative concentration, mineral catalysis, and localized energy inputs could coincide spatially and temporally. Ultraviolet radiation and lightning provide complementary energy sources, while mineral surfaces such as clays and iron sulfides enhance molecular stability and reactivity. The probability of abiogenesis is expressed as a function of environmental opportunity, parameterized by the number of active environments, their persistence timescales, and the frequency of productive chemical events (formalized in Appendix~A). Under conservative assumptions, the resulting probabilities are non-negligible, indicating that life’s emergence on early Earth was plausible but not inevitable. Comparative estimates suggest that surface ponds and, secondarily, the oceanic surface microlayer provide favorable conditions relative to more dilute or continuously aqueous environments. By quantitatively linking prebiotic chemistry, mineral evolution, and planetary energy fluxes, this framework constrains the emergence of life to realistic Archean conditions and offers testable guidance for astrobiology. Transient aqueous niches characterized by mineral diversity and cyclic energy inputs emerge as promising targets in the search for life beyond Earth.