Greenalite Nanoparticles in Alkaline Vent Plumes as Templates for the Origin of Life

Abstract

Mineral templates are thought to have played keys roles in the emergence of life. Drawing on recent findings from 3.45-2.45 billion-year-old iron-rich hydrothermal sedimentary rocks, we hypothesize that greenalite (Fe 3 Si 2 O 5 (OH) 4) was a readily available mineral in hydrothermal environments, where it may have acted as a template and catalyst in polymerization, vesicle formation and encapsulation, and protocell replication. We argue that venting of dissolved Fe 2+ and SiO 2 (aq) into the anoxic Hadean ocean favored the precipitation of nanometer-sized particles of greenalite in hydrothermal plumes, producing a continuous flow of free-floating clay templates that traversed the ocean. The mixing of acidic, metal-bearing hydrothermal plumes from volcanic ridge systems with more alkaline, organic-bearing plumes generated by serpentinization of ultramafic rocks brought together essential building blocks for life in solutions conducive to greenalite precipitation. We suggest that the extreme disorder in the greenalite crystal lattice, producing structural modulations resembling parallel corrugations (*22 Å wide) on particle edges, promoted the assembly and alignment of linear RNA-type molecules (*20 Å diameter). In alkaline solutions, greenalite nanoparticles could have accelerated the growth of membrane vesicles, while their encapsulation allowed RNA-type molecules to continue to form on the mineral templates, potentially enhancing the growth and division of primitive cell membranes. Once self-replicating RNA evolved, the mineral template became redundant, and protocells were free to replicate and roam the ocean realm.

Carbonate‐Associated Phosphate (CAP) Indicates Elevated Phosphate Availability in Neoarchean Shallow Marine Environments

“…A growing body of evidence has raised the hypothesis that Archean seawater phosphate concentrations may have been higher than present day levels in open marine environments (Planavsky et al., 2010; Rasmussen, Muhling, & Fischer, 2021; Rasmussen, Muhling, Suvorova, & Fischer, 2021). Recent discovery of apatite nanoparticles associated with the Fe(II)‐silicate greenalite within early diagenetic chert in 3.46 to 2.46 Ga BIFs from the Pilbara and Yilgarn cratons (Australia) and Kaapvaal craton (South Africa) supported this hypothesis (Rasmussen, Muhling, Suvorova, & Fischer, 2021).…”

‘Whole Organism’, Systems Biology, and Top-Down Criteria for Evaluating Scenarios for the Origin of Life

“…Most begin with a specific venue for the initiation of prebiotic chemistry, although some advocate for the role of multiple environments in life’s origin [ 7 , 8 , 9 , 10 ]. Proposed beginning venues include marine alkaline hydrothermal vents, either within microchambers [ 11 , 12 , 13 , 14 , 15 , 16 ] or iron (oxy)hydroxide (green rust) mounds [ 2 , 17 ], hydrothermally/volcanically charged sediments [ 18 , 19 ], terrestrial geothermal hot springs [ 20 ] including at their edges [ 21 , 22 ], within the pores of pumice rafts [ 23 , 24 ], between layers of micas [ 25 ], on clay surfaces [ 26 ] or greenalite nanoparticles [ 27 ], and even within the atmosphere as the key venue for initial biosynthesis fueled by a major meteorite impact [ 10 ]. Many of these have been recently summarized and evaluated [ 28 ], and we do not undertake a comprehensive analysis of the proposed starting venues here.…”

Marine phosphate availability and the chemical origins of life on Earth

“…Our results suggest that Hadean oceans could have delivered a crucial prebiotic feedstock molecule to a wide array of marine systems, where interaction with reactive solid and aqueous species may have facilitated key steps toward biosynthesis 36 . Beyond the marine realm, dry land is often invoked to concentrate feedstock chemicals and leverage selective photochemistry afforded by solar radiation [2][3][4]13 .…”