Rapid emergence of life shown by discovery of 3,700-million-year-old microbial structures

@article{Nutman2016RapidEO,
  title={Rapid emergence of life shown by discovery of 3,700-million-year-old microbial structures},
  author={Allen P. Nutman and Vickie C. Bennett and Clark R.L. Friend and Martin Van Kranendonk and Allan R. Chivas},
  journal={Nature},
  year={2016},
  volume={537},
  pages={535-538}
}
Biological activity is a major factor in Earth’s chemical cycles, including facilitating CO2 sequestration and providing climate feedbacks. Thus a key question in Earth’s evolution is when did life arise and impact hydrosphere–atmosphere–lithosphere chemical cycles? Until now, evidence for the oldest life on Earth focused on debated stable isotopic signatures of 3,800–3,700 million year (Myr)-old metamorphosed sedimentary rocks and minerals from the Isua supracrustal belt (ISB), southwest… 

Reassessing evidence of life in 3,700-million-year-old rocks of Greenland

Three-dimensional analysis of the morphology and orientation of the structures within the context of host rock fabrics, combined with texture-specific analyses of major and trace element chemistry, show that the ‘stromatolites’ are more plausibly interpreted as part of an assemblage of deformation structures formed in carbonate-altered metasediments long after burial.

Microbial life and biogeochemical cycling on land 3,220 million years ago

The colonization of emergent continental landmass by microbial life was an evolutionary step of paramount importance in Earth history. Here we report direct fossil evidence for life on land 3,220

Morpho- and Chemo-Fossil Evidence of Early Life

This chapter summarizes what is known about the timing of the emergence of life on Earth from the morpho- and chemo-fossil (chemical and isotopic signals remaining from the decomposition of living

Paleo-Rock-Hosted Life on Earth and the Search on Mars: A Review and Strategy for Exploration

Findings suggest that rock-hosted life would have been more likely to emerge and be preserved in a martian context, and outline a Mars exploration strategy that targets subsurface life and scales spatially, focusing initially on identifying rocks with evidence for groundwater flow and low-temperature mineralization, then identifying redox and permeability interfaces preserved within rock outcrops.

Geology: Evidence of life in Earth's oldest rocks

  • A. Allwood
  • Geology, Environmental Science
    Nature
  • 2016
This report describes metamorphosed stromatolites deposited around 3,700 million years ago in what is now Greenland, which is more than 200 million years older than the previous record-holders for earliest-known fossils, so these strom atolites rank as the Earth's earliest fossils by some margin.

Importance of Prokaryotes in the Functioning and Evolution of the Present and Past Geosphere and Biosphere

On a volcanic and anaerobic planet characterized by abundant hydrothermal activity, physicochemical gradients and disequilibria at the local scale would have been fundamental for the emergence of

Metabolic specializations within a bacterial community to create living rocks

It is proposed that abundance of extracellular alkaline phosphatases, in combination with the absence of transport regulatory enzymes, may lead to the precipitation of phosphatic deposits within these stromatolites, and it is concluded that the cumulative effect of several conserved bacterial species drives accretion in these two strom atolite formations.

The Martian subsurface as a potential window into the origin of life

Few traces of Earth’s geologic record are preserved from the time of life’s emergence, over 3,800 million years ago. Consequently, what little we understand about abiogenesis — the origin of life on
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