When did Life Likely Emerge on Earth in an RNA-First Process?

Abstract

The widespread presence of ribonucleic acid (RNA) catalysts and cofactors in Earth's biosphere today suggests that RNA was the first biopolymer to support Darwinian evolution. However, most "path-hypotheses" to generate building blocks for RNA require reduced nitrogen-containing compounds not made in useful amounts in the CO2-N2-H2O atmospheres of the Hadean. We review models for Earth's impact history that invoke a single ~10^23 kg impactor (Moneta) to account for measured amounts of platinum, gold, and other siderophilic ("iron-loving") elements on the Earth and Moon. If it were the last sterilizing impactor, Moneta would have reduced the atmosphere but not its mantle, opening a "window of opportunity" for RNA synthesis, a period when RNA precursors rained from the atmosphere to land holding oxidized minerals that stabilize advanced RNA precursors and RNA. Surprisingly, this combination of physics, geology, and chemistry suggests a time when RNA formation was most probable, ~120 +/- 100 million years after Moneta's impact, or ~4.36 +/- 0.1 billion years ago. Uncertainties in this time are driven by uncertainties in rates of productive atmosphere loss and amounts of sub-aerial land.

arXiv commentPaper accepted to ChemSystemsChem [https://onlinelibrary.wiley.com/journal/25704206] August 22, 2019

References in corpus (15)

• The Pale Orange Dot: The Spectrum and Habitability of Hazy Archean Earth
• Transient reducing greenhouse warming on early Mars
• Origin of the RNA World: The Fate of Nucleobases in Warm Little Ponds
• Cataclysm no more: New views on the timing and delivery of lunar impactors
• Highly siderophile elements were stripped from Earth's mantle by iron sulfide segregation
• Pale Orange Dots: The Impact of Organic Haze on the Habitability and Detectability of Earthlike Exoplanets
• Onset of giant planet migration before 4480 million years ago
• The terrestrial late veneer from core disruption of a lunar-sized impactor
• Evolution of the solar activity over time and effects on planetary atmospheres. II. kappa^1 Ceti, an analog of the Sun when life arose on Earth
• Nitrogen Oxide Concentrations in Natural Waters on Early Earth
• Late veneer and late accretion to the terrestrial planets
• The Last Stages of Terrestrial Planet Formation: Dynamical Friction and the Late Veneer
• Measuring the Abundance of sub-kilometer sized Kuiper Belt Objects using Stellar Occultations
• Ejection of iron-bearing giant-impact fragments and the dynamical and geochemical influence of the fragment re-accretion
• Jupiter's influence on the building blocks of Mars and Earth

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