Questioning the Paradigm of a Phosphate?Limited Archean Biosphere

The nature of Archean life remains one the most contested topics in study Earth history. debate may be formulated as follows: When did present day metabolisms emerge to ecological significance? What limited productivity early biospheres? How existence and individual affect chemistry oxidation state ocean-atmosphere? In a new study, Ingalls et al. (2022, https://doi.org/10.1029/2022GL098100) apply novel proxy, carbonate-associated phosphate (CAP), Neoarchean carbonate rocks argue that seawater was more phosphate-rich than through Phanerozoic time. Although interpretation CAP signals is currently burdened by uncertainties regarding chemistry, their results suggest levels were comparable modern seawater, if not higher. If true, then Earth's successful metabolism, oxygenic photosynthesis, had either achieved prominence exploit relatively waters, or curtailed other under-appreciated mechanisms.