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Rationale: Why Origin of Life matters to Mars exploration?

First and Last Outposts: The Origin and Preservation of Life in Terrestrial and Martian Hydrothermal Fields Mars2020 Third Landing Site Selection Workshop Monrovia, CA 8-10 Feb 2017 Bruce Damer, University of California, Santa Cruz David Deamer, Martin Van Kranendonk, Malcolm Walter, Tara Djokic.

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Rationale: Why Origin of Life matters to Mars exploration?

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  1. First and Last Outposts: The Origin and Preservation of Life in Terrestrial and Martian Hydrothermal FieldsMars2020 Third Landing Site Selection Workshop Monrovia, CA 8-10 Feb 2017 Bruce Damer, University of California, Santa CruzDavid Deamer, Martin Van Kranendonk, Malcolm Walter, Tara Djokic NOTE ADDED BY JPL WEBMASTER: This content has not been approved or adopted by, NASA, JPL, or the California Institute of Technology. This document is being made available for information purposes only, and any views and opinions expressed herein do not necessarily state or reflect those of NASA, JPL, or the California Institute of Technology.

  2. History: hand count that sent Spirit to GusevJPL final MER landing site selection meeting-Jan 2003

  3. Rationale: Why Origin of Life matters to Mars exploration? In a search for evidence of ancient life in the earliest (Noachian) history of Mars, it would be useful to apply a chemical and geological framework for an origin of life on a terrestrial world. In recent years the origin of life field has undergone a paradigm shift and established some guiding principals in the chemistry, geology, thermodynamics, combinatorics and evolution for both an origin and early life phases. Applying these principles we can posit when, where, and how long life needs to start and robustly establish on Earth or Mars. Recent discoveries providing a body of evidence: Pilbara 3.5Ga terrestrial hot springs are a primary early driver for life on Earth; new laboratory discoveries suggest a viable chemical pathway.

  4. The Science of the Origin of Life: Charles Darwin’s intuition-1871 "But if (and oh what a big if) we could conceive in some warm little pond with all sorts of ammoniaand phosphoric salts, light, heat, electricity etcetera present, that a protein compound was chemically formed, ready to undergo still more complex changes [..] " ~Charles Darwin, in a letter to Joseph Hooker (1871)

  5. The Science of Origin of Life: 1920s-50s Haldane-Oparin “soups” Alexander Oparin's and J. B. S. Haldane's hypothesis: putative conditions on the primitive Earth favored chemical reactions that synthesized more complex organic compounds from simpler inorganic precursors. 1953-Miller-Urey spark chamber synthesis Synthesis of amino acids launched experimental phase of origin of life research. 1977 Discovery-deep sea hydrothermal vents Suggested as a location for an origin of life by Corliss, Russell, Martin, Lane et al. Polymerization and encapsulation not yet demonstrated. -> Chemistry community now returning its focus toland-based pools.

  6. Discovery: prebiotic, non-enzymatic polymerization Hydration-dehydration cycling – David Deamer 1980s CO2 atmosphere, 85 C, pH 3 Hydration-dehydration cycles with nucleobases (A, U) in presence of lipid -> RNA-like polymers are produced through a few cycles of 4-24 hours. CO2 dehydration H2O rehydration Hydration-dehydration of amino acids ->peptides (Hud, Cronin).

  7. Field testing the hypothesis: “Hot Little Pool” Kamchatka Russia Pools collect & concentrate molecular inventories: meteoritic (IDPs) and hydrothermal sources for nucleobases, amino acids, fatty acids, key elements (C, Zn, B, P, and N), minerals for prebiotic chemistry. Access to 3 energy sources: heat activation, dehydration and sunlight. Regular wet-dry cycling in presence of membranes to drive polymerization reactions. Membraneous structures form in hydrothermal field conditions from 14 carbon fatty acid, glycerol, Phosphate, @ pH 3.

  8. Field testing the hypothesis: fumarole polymerizationBumpass Hell, Mount Lassen Volcanic Park, California 2 nucleobases (A,U) + amphiphile (Phosphatidylcholine) @ pH 3 Polymerization of RNA-like polymers has now been observed in exposure to hydrothermal field conditions

  9. Encapsulation of synthesized polymers When dried lipid layers are exposed to rehydration, large numbers of vesicles “bud off” some containing random polymers. Each provides an experiment in a natural process of combinatorial selection for function (stabilization, pores, metabolism). Lipid: decanoic acid+ decanoyl monoglyceride Monomers: dAMP+TMP Fluorescent stain: DAPI Cyclic polymerization of nucleotides works in presence of clay or dissolved silica.

  10. Terrestrial Origin of Life Hypothesis Life(2015, 2016) ScientificAmerican(forthcoming)

  11. ChemicalFramework Three coupled phases cycle polymers toward increasing complexity. Competition and cooperation drive molecular evolution toward a robust progenote (Woese & Fox) a protocell aggregate capable of growth, distribution and adaptation.

  12. Geological Framework Downhill distribution subjects progenotes to adaptive pathways… …and determines where life ends up

  13. The “Goldilocks chemistry” (Joyce) for an origin of life is found in inland hydrothermal “warm little fluctuating pools”. time Optimal Extreme

  14. “Pools of fitness” and downhill distribution provides resources and evolutionary gradients for early life collect concentrate distribute cycle adapt stress Early life on Earth had hundreds of millions of years to establish robust adaptations such as photoautotrophy and protein synthesis. Early life on Mars would be in a race against a rapidly retracting habitable environment.

  15. Conclusion: Hydrothermal sites are potentialfirst and last outpostsfor life on Mars • Like Earth, conditions for an origin of life on Mars would have existed at early (>3.5Ga) hydrothermal “first outposts” like Home Plate: fresh water precipitation, wet-dry cycling, IDP reagent in-fall, & geothermal feeder chemistry. However, facing a dying planet, farther from life’s Goldilocks chemistry in hydrothermal outcrops there is increasing risk that life was unable to persist, and will not be found. • Long term access to the surface by surviving rock-hosted deep Mars biosphere chemotrophic/halophilic communities could be detectable at hot spring outcrop “last outpost” like Home Plate, which on Earth provide the oldest and best preservation of life. • Home Plate therefore has high astrobiology relevance: potential biosignatures have already been demonstrated and return samples could provide a fundamental scientific discovery bearing on life on Mars but also the origin of life on the Earth.

  16. Acknowledgements Collaborators and Supporters UC Santa Cruz Australian Centre for Astrobiology Univ. New South Wales McMaster University Center for Chemical Evolution, Georgia Tech. Cronin Lab, University of Glasgow Thanks to Steve Ruff @ ASU for inviting our participation Biota Institute: origins.biota.org Contact: Bruce Damer bdamer@ucsc.edu University of Paris University of Washington Harry Lonsdale Research Award NASA DigitalSpace Research

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