Biosignatures in Deep Time
International audience Life on the early Earth inhabited a planet whose environment was vastly different from the Earth of today. An anaerobic and hot early Earth was the birthplace of the first living cells but wide-spread small-scale physico-chemical diversity provided opportunities for a variety...
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ftunivorleans:oai:HAL:hal-02067828v1 2024-09-15T18:10:02+00:00 Biosignatures in Deep Time Westall, Frances Hickman-Lewis, Keyron Cavalazzi, Barbara Centre de biophysique moléculaire (CBM) Université d'Orléans (UO)-Université de Tours (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS) Alma Mater Studiorum Università di Bologna = University of Bologna (UNIBO) Barbara Cavalazzi, Frances Westall 2019-10-02 https://hal.science/hal-02067828 https://doi.org/10.1007/978-3-319-96175-0 en eng HAL CCSD Springer info:eu-repo/semantics/altIdentifier/doi/10.1007/978-3-319-96175-0 ISBN: 978-3-319-96174-3 hal-02067828 https://hal.science/hal-02067828 doi:10.1007/978-3-319-96175-0 Biosignatures for Astrobiology https://hal.science/hal-02067828 Barbara Cavalazzi, Frances Westall. Biosignatures for Astrobiology, Springer, pp.145-164, 2019, 978-3-319-96174-3. ⟨10.1007/978-3-319-96175-0⟩ [CHIM]Chemical Sciences info:eu-repo/semantics/bookPart Book sections 2019 ftunivorleans https://doi.org/10.1007/978-3-319-96175-0 2024-07-01T23:44:19Z International audience Life on the early Earth inhabited a planet whose environment was vastly different from the Earth of today. An anaerobic and hot early Earth was the birthplace of the first living cells but wide-spread small-scale physico-chemical diversity provided opportunities for a variety of specialists: alkalophiles, acidophiles, halophiles etc. The earliest record of life has been lost due to plate tectonic recycling and the oldest preserved terranes (~3.9–3.7 Ga) are heavily altered by metamorphism, although they may contain traces of fossil life. As of ~3.5 Ga, ancient sediments are so well-preserved that a broad diversity of micro-environments and fossil traces of life can be studied, providing a surprising window into communities of microbes that had already reached the evolutionary stage of photosynthesis. From the wide variety of traces of ancient life that have been reported from the Archaean geological record in Greenland, Canada, South Africa and Western Australia, we examine a few particularly pertinent examples. Biosignatures in the rock record include microfossils, microbial mats, stromatolites, microbially induced sedimentary structures, biominerals, biologically indicative isotopic ratios and fractionations, elemental distributions, organochemical patterns and other geochemical peculiarities best explained by biological mediation. Due to dynamic geological reprocessing over the billions of years since these fossils entered the rock record, identifications of very ancient traces of life have been subject to criticism, hence the often complex arguments regarding their biogenicity. We here highlight a range of unambiguously bona fide and widely supported examples of fossil biosignatures. Fossil biosignatures have great promise as analogues of life that might be detected on other planets. In this respect, the study of the early Earth is particularly pertinent to the search for life on Mars, given the planetary- and microbial-scale similarities that prevailed on both planets during their ... Book Part Greenland Université d'Orléans: HAL 145 164 |
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[CHIM]Chemical Sciences |
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[CHIM]Chemical Sciences Westall, Frances Hickman-Lewis, Keyron Cavalazzi, Barbara Biosignatures in Deep Time |
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[CHIM]Chemical Sciences |
description |
International audience Life on the early Earth inhabited a planet whose environment was vastly different from the Earth of today. An anaerobic and hot early Earth was the birthplace of the first living cells but wide-spread small-scale physico-chemical diversity provided opportunities for a variety of specialists: alkalophiles, acidophiles, halophiles etc. The earliest record of life has been lost due to plate tectonic recycling and the oldest preserved terranes (~3.9–3.7 Ga) are heavily altered by metamorphism, although they may contain traces of fossil life. As of ~3.5 Ga, ancient sediments are so well-preserved that a broad diversity of micro-environments and fossil traces of life can be studied, providing a surprising window into communities of microbes that had already reached the evolutionary stage of photosynthesis. From the wide variety of traces of ancient life that have been reported from the Archaean geological record in Greenland, Canada, South Africa and Western Australia, we examine a few particularly pertinent examples. Biosignatures in the rock record include microfossils, microbial mats, stromatolites, microbially induced sedimentary structures, biominerals, biologically indicative isotopic ratios and fractionations, elemental distributions, organochemical patterns and other geochemical peculiarities best explained by biological mediation. Due to dynamic geological reprocessing over the billions of years since these fossils entered the rock record, identifications of very ancient traces of life have been subject to criticism, hence the often complex arguments regarding their biogenicity. We here highlight a range of unambiguously bona fide and widely supported examples of fossil biosignatures. Fossil biosignatures have great promise as analogues of life that might be detected on other planets. In this respect, the study of the early Earth is particularly pertinent to the search for life on Mars, given the planetary- and microbial-scale similarities that prevailed on both planets during their ... |
author2 |
Centre de biophysique moléculaire (CBM) Université d'Orléans (UO)-Université de Tours (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS) Alma Mater Studiorum Università di Bologna = University of Bologna (UNIBO) Barbara Cavalazzi, Frances Westall |
format |
Book Part |
author |
Westall, Frances Hickman-Lewis, Keyron Cavalazzi, Barbara |
author_facet |
Westall, Frances Hickman-Lewis, Keyron Cavalazzi, Barbara |
author_sort |
Westall, Frances |
title |
Biosignatures in Deep Time |
title_short |
Biosignatures in Deep Time |
title_full |
Biosignatures in Deep Time |
title_fullStr |
Biosignatures in Deep Time |
title_full_unstemmed |
Biosignatures in Deep Time |
title_sort |
biosignatures in deep time |
publisher |
HAL CCSD |
publishDate |
2019 |
url |
https://hal.science/hal-02067828 https://doi.org/10.1007/978-3-319-96175-0 |
genre |
Greenland |
genre_facet |
Greenland |
op_source |
Biosignatures for Astrobiology https://hal.science/hal-02067828 Barbara Cavalazzi, Frances Westall. Biosignatures for Astrobiology, Springer, pp.145-164, 2019, 978-3-319-96174-3. ⟨10.1007/978-3-319-96175-0⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1007/978-3-319-96175-0 ISBN: 978-3-319-96174-3 hal-02067828 https://hal.science/hal-02067828 doi:10.1007/978-3-319-96175-0 |
op_doi |
https://doi.org/10.1007/978-3-319-96175-0 |
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145 |
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164 |
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1810447637604728832 |