Earth's Early Atmosphere

  title={Earth's Early Atmosphere},
  author={U. Wiechert},
  pages={2341 - 2342}
New evidence indicates that before 2400 million years ago, Earth's atmosphere contained no more than trace amounts of oxygen. In his Perspective, [Wiechert][1] reviews the latest evidence reported by [Farquhar][2] et al ., who have analyzed the sulfur isotope composition of ancient inclusions in diamond. These inclusions were transported into the mantle by subduction and reached Earth's surface again by explosive volcanism. Further insights into conditions on early Earth are provided by Habicht… Expand
Darwin’s warm little pond revisited: from molecules to the origin of life
In this review, this review has concentrated on experimental and theoretical research published over the last two decades, which has added a wealth of new details and helped to close gaps in previous understanding of this multifaceted field. Expand
Early Cell Evolution, Eukaryotes, Anoxia, Sulfide, Oxygen, Fungi First (?), and a Tree of Genomes Revisited
New views of eukaryote phylogeny suggest that fungi may be among the earliest‐branching eUKaryotes, and from the standpoint of the fungal feeding habit (osmotrophy rather than phagotrophy) and the diversity in their ATP‐producing pathways, a eucaryotic tree with fungi first would make sense. Expand
Studies on Tropical Palaeo-variation in Climate and Cosmic Ray Influx : Geochemical data from stalagmites collected in Tanzania and northern South Africa
The main aims of this project were to contribute to the knowledge about tropical climate variations, and to investigate the possibilities of obtaining cosmic ray influx data fromExpand
Methane-rich fluid inclusions from ophiolitic dunite and post-collisional mafic–ultramafic intrusion: The mantle dynamics underneath the Palaeo-Asian Ocean through to the post-collisional period
Abstract The protracted development history of the Palaeo-Asian Ocean starting from ∼1000 Ma to ∼320 Ma, and continuation of mantle-derived magmatism right through the post-collisional period asExpand
Importance of Biologically Active Aurora-like Ultraviolet Emission: Stochastic Irradiation of Earth and Mars by Flares and Explosions
The results suggest that coding organisms on such planets (and on the early Earth) may evolve very differently than on contemporary Earth, with diversity and evolutionary rate controlled by a stochastically varying mutation rate and frequent hypermutation episodes. Expand
The Drake Equation in an astrobiological context
  • G. Konesky
  • Physics, Engineering
  • Optical Engineering + Applications
  • 2010
The Drake Equation was originally composed as an attempt to quantify the potential number of extraterrestrial civilizations in our Galaxy which we might be able to detect using a radio telescope.Expand
The Evolution of Oxygen-Independent Energy Metabolism in Eukaryotes with Hydrogenosomes and Mitosomes
This chapter serves to further revise the role of oxygen in eukaryote evolution in light of surprising findings about O2 and energetics and inlight of what geologists have discovered regarding the timing of oxygen accumulation in Earth history. Expand
Nitrogen Deposition Via N+ Implantation: Implications for Primordial Amino Acids Synthesis Revisited
In this paper amino acids synthesis in aqueous solution induced by ion implantation, which was possibly ubiquitous on primitive Earth, is investigated. As a discharge using a graphite rod as theExpand
Fundamental molecules of life are pigments which arose and co-evolved as a response to the thermodynamic imperative of dissipating the prevailing solar spectrum
Abstract. The driving force behind the origin and evolution of life has been the thermodynamic imperative of increasing the entropy production of the biosphere through increasing the global solarExpand
Methanogens: a window into ancient sulfur metabolism.
Contrary to this hypothesis, methanogens do not utilize sulfate as a sulfur source, Cys is not utilized as an sulfur donor for Fe-S cluster and Met biosynthesis, and Cys biosynthesis uses an unusual tRNA-dependent pathway. Expand


Atmospheric influence of Earth's earliest sulfur cycle
Mass-independent isotopic signatures in Precambrian rocks indicate that a change occurred in the sulfur cycle between 2090 and 2450 million years ago, implying that atmospheric oxygen partial pressures were low and that the roles of oxidative weathering and of microbial oxidation and reduction of sulfur were minimal. Expand
A new model for Proterozoic ocean chemistry
There was a significant oxidation of the Earth's surface around 2 billion years ago (2 Gyr). Direct evidence for this oxidation comes, mostly, from geological records of the redox-sensitive elementsExpand
Isotope evidence for the involvement of recycled sediments in diamond formation
DIAMONDS, as chemically robust containers of material from the mantle, have provided important information regarding the evolution of the Earth's interior1; yet despite much effort2–9, the origins ofExpand
Greenhouse warming by CH4 in the atmosphere of early Earth.
It is found that a CH4 mixing ratio of 10(-4) (100 ppmv) or more in Earth's early atmosphere would provide agreement with the paleosol data from 2.3-2.4 Ga, which could have triggered the Earth's first widespread glaciation. Expand
The Archean sulfur cycle and the early history of atmospheric oxygen.
Sedimentary sulfur isotope record suggests low concentrations of seawater sulfate and atmospheric oxygen in the early Archean and early Proterozoic and shows how sulfate reduction rate influences the preservation of biological fractionations in sediments. Expand
Biogenic Methane, Hydrogen Escape, and the Irreversible Oxidation of Early Earth
Expected irreversible oxidation (∼1012 to 1013 moles oxygen per year) may help explain how Earth's surface environment became irreversibly oxidized. Expand
Calibration of Sulfate Levels in the Archean Ocean
Sulfur isotope fractionation experiments on marine and freshwater sulfate reducers, together with the isotope record, imply that oceanic Archean sulfate concentrations were less than one-hundredth of present marine sulfate levels and one-fifth of what was previously thought. Expand
Mass-Independent Sulfur of Inclusions in Diamond and Sulfur Recycling on Early Earth
Populations of sulfide inclusions in diamonds from the Orapa kimberlite pipe in the Kaapvaal-Zimbabwe craton, Botswana, preserve mass-independent sulfur isotope fractionations. The data indicate thatExpand
Sulphur isotope heterogeneity in the mantle from ion microprobe measurements of sulphide inclusions in diamonds
The sulphur isotope composition of the mantle has been generally considered to be 0±2‰1. There is, however, considerable uncertainty in the mean δ34S value of the mantle and in its range becauseExpand
Eclogitic diamond formation at jwaneng: No room for a recycled component
Paired delta15N-delta13C-N variations in 40 eclogitic diamonds from the Jwaneng kimberlite in Botswana show that neither the influence of recycled biogenic carbon nor the global and primordial heterogeneity of mantle carbon are likely for the origin of the large delta13C range; the data instead support a fractionation process. Expand