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Titel |
Habitability from a microbial point of view |
VerfasserIn |
Frances Westall, Damien Loizeau, Frédéric Foucher, Nicolas Bost, Marylène Bertrand, Jorge Vago, Gerhard Kminek |
Konferenz |
EGU General Assembly 2014
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Medientyp |
Artikel
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Sprache |
Englisch
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Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 16 (2014) |
Datensatznummer |
250095031
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Publikation (Nr.) |
EGU/EGU2014-10471.pdf |
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Zusammenfassung |
We examine here the definition of habitability from the point of view of primitive, anaerobic
microorganisms noting that the conditions of habitability are different for the appearance of
life, for established life, and for life in dormant mode [1]. Habitability in this sense is clearly
distinguished from the “prebiotic world” that precedes the appearance of life. The differences
in the conditions of habitability necessary for life to appear, for life to flourish and for
dormant life entrain differences in spatial and temporal scales of habitability. For
the origin of life, the ingredients carbon molecules, water, nutrients and energy
need to be present on time scales applicable for the origin of life (105 to a few 106
y ?), necessitating the spatial scales of a minimum of ~100 km. Established life
can take advantage of short-lived habitats (hours, days) to much longer lived ones
on spatial scales of 100s μm to cm-m, whereas dormant life can survive (but not
metabolise) in extreme environments for very long periods (perhaps up to millions of
years) at microbial spatial scales (100s μm – mms). Thus, it is not necessary for the
whole of a planet of satellite to be habitable. But the degree of continued habitability
will have a strong influence on the possibility of organisms to evolve. For a planet
such as Mars, for instance, microbial habitability was (perhaps still is) at different
times and in different places. Habitable conditions conducive to the appearance
of life, established life and possibly even dormant life could co-exist at different
locations.
Reference:
[1] F. Westall, D. Loizeau, F. Foucher, N. Bost, M. Bertrand, J. Vago, & G. Kminek,
Astrobiology 13:9, 887-897 (2013). |
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