Increase of chemical complexity

A global hydrothermal reactor triggered prebiotic synthesis on Earth

Nicolas Winssinger (Department of Organic Chemistry, UniGE), Luca Caricchi, (Department of Earth Sciences, UniGE), Chiara Boschi and Andrea Dini (Institute of Geosciences and Earth Resources, CNR, Italy)

Biosignatures in the rock record limit the time available for life to start on Earth to 600-800 million years (4.5-3.7 Ga; Hadean-Archean). Hydrothermal environments have been postulated as privileged environments for the emergence of life but, today, they are present on extremely small portions of the Earth. The specific tectonic conditions of the Hadean made our planet a global hydrothermal reactor, thus maximizing the probability of occurrence of favorable environments for the emergence of the building blocks of life. Phosphorus and boron, considered essential for the synthesis of prebiotic molecules, were extremely scarce on Hadean Earth. The establishment of a global hydrothermal reactor resulted in the production of enormous quantities of brucite, a mineral capable of absorbing and concentrating both elements. However, the impact of brucite on prebiotic chemistry, in particular, the catalytic properties of porous minerals with a surface functionalized with boron and phosphate have not been investigated. While organophosphates are central to life as we know it (DNA, RNA, phospholipids, energy currency), the scarcity of phosphate in prebiotic oceans, lakes and pools is prohibitive for the emergence of life. Capitalizing on the existing expertise at the University of Geneva and ongoing collaborations with the CNR in Italy, in the framework of the Life in the Universe initiative we have designed an experimental workflow to test the catalytic role of brucite on the emergence of prebiotic molecules. Specifically, porous brucite with high surface area of boron and phosphate, doped with different metals such as iron (FeII or III), will be used to test its impact on the formation of RNA and lipid precursors under prebiotic conditions.