W
wildleafblower
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I was doing research on another topic that I was preparing to present to Ed when I ran across the following:
Astrophysics and Space Science(2008) 317: 145–146
DOI 10.1007/s10509-008-9920-6
LETTERS TO THE EDITOR
Pitfalls of geocentricism
Max K. Wallis2 , M. Wainwright2, J. T. Wickramasinghe1 and N. C. Wickramasinghe2
(1) Cardiff Centre for Astrobiology, Cardiff University, Cardiff, CF10 3DY, UK
(2) Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
Received: 17 September 2008 / Accepted: 17 September 2008 / Published online: 29 October 2008
Abstract The principles of biogeography have little or no direct relevance in an astrobiological context. If a microbial ecosystem exists on one planetary body, its spread to neighbouring planets is controlled by available transfer routes with adequate survival en route and appropriate nutrient and growth conditions on the host planetary body.
[snip]
1 Biogeography
The modern science of biogeography cited by Ebach et al. (2008) seeks to explain patterns of species distribution on This letter to the editor is related to the other two letters available at . . .[snip-please review online]
Earth in terms of evolutionary relationships and movement pathways. But it has little to say about microorganisms in the deep biosphere of sediments, antarctic icecap, ocean bed
‘smokers’ and other marginal environments where extremeophiles have been discovered in huge variety.
The pioneer of biogeography Alfred Russel Wallace (1863) discovered major discontinuities in animal species across the “Wallace line” in the Malay peninsula, the first example of a geographical barriers for dispersal and interbreeding. Spatial connections between related groups of species are relatively straightforward to delineate for the dispersal of terrestrial life. Paleobiogeography of the fossil record includes geological movements, while phylogenetics indicates evolutionary pathways and times. The biogeography of Ebach et al. (2008) depends on accessibility to experimental science. But it’s relevance to astrosciences and in particular studies of environments for life in the solar system and dispersal of life between them remains uncertain.
For the possible dispersal of extraterrestrial life the ground rules are necessarily different. We know of no place outside Earth where life exists with certainty. One could either identify promising extraterrestrial habitats and argue that life originates de novo with relative ease, or argue the opposite that it does not. Since the origin of life remains unsolved by science, with the Oparin-Haldane-Urey approach far from proving Earth-based mechanisms, the option of rare origination on the astronomical scale plus dispersal of space-hardy forms is worthy of study.
Recent discoveries relating to the survival attributes of extremophilic microorganisms point in favour of the latter option (Vreeland et al.2000; Horneck et al. 2001).
springerlink.com/content/q116k7464885l307/
http://www.springerlink.com/content/q116k7464885l307/
Interesting!