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

Rasmussen, B. and Muhling, J. R. and Fischer, W. W. (2021) Greenalite Nanoparticles in Alkaline Vent Plumes as Templates for the Origin of Life. Astrobiology, 21 (2). pp. 246-259. ISSN 1531-1074.

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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 (Fe₃Si₂O₅ (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 Fe²⁺ and SiO₂ (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.

Item Type:Article
Related URLs:
URLURL TypeDescription
Rasmussen, B.0000-0001-5052-6797
Muhling, J. R.0000-0003-1890-9119
Fischer, W. W.0000-0002-8836-3054
Additional Information:© 2020 B. Rasmussen et al., 2020; Published by Mary Ann Liebert, Inc. This Open Access article is distributed under the terms of the Creative Commons Attribution Noncommercial License ( which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited. Submitted 30 March 2020; Accepted 7 September 2020; Online Ahead of Print: October 20, 2020. B.R. and J.R.M. received support from Australian Research Council grants DP140100512 and DP190102237. W.W.F. acknowledges support of the Simons Foundation Collaboration on the Origins of Life. Support for the acquisition of the scientific drill cores was provided by the Agouron Institute and NASA Astrobiology Program. Electron microscopy was performed at the Centre for Microscopy, Characterisation and Analysis at the University of Western Australia, a node of Microscopy Australia, funded from university and government sources. We thank S. Bengtson for comments on an early version of the manuscript and two anonymous journal reviewers for their helpful comments. No competing financial interests exist. Associate Editor: Nita Sahai
Funding AgencyGrant Number
Australian Research CouncilDP140100512
Australian Research CouncilDP190102237
Simons FoundationUNSPECIFIED
Agouron InstituteUNSPECIFIED
Subject Keywords:Origin of life; Alkaline vents; Greenalite; Clay templates; RNA; Hydrothermal sediments
Issue or Number:2
Record Number:CaltechAUTHORS:20201027-082416105
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Official Citation:B. Rasmussen, J.R. Muhling, and W.W. Fischer. Astrobiology. Feb 2021. 246-259.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:106290
Deposited By: Tony Diaz
Deposited On:27 Oct 2020 17:06
Last Modified:09 Feb 2021 23:33

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