Raman spectroscopic approach to analytical astrobiology: the detection of key geological and biomolecular markers in the search for life

Abstract

You have accessMoreSectionsView PDF ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmail Cite this article Edwards Howell G. M. 2010Raman spectroscopic approach to analytical astrobiology: the detection of key geological and biomolecular markers in the search for lifePhil. Trans. R. Soc. A.3683059–3065http://doi.org/10.1098/rsta.2010.0100SectionYou have accessIntroductionRaman spectroscopic approach to analytical astrobiology: the detection of key geological and biomolecular markers in the search for life Howell G. M. Edwards Howell G. M. Edwards [email protected] Google Scholar Find this author on PubMed Search for more papers by this author Howell G. M. Edwards Howell G. M. Edwards [email protected] Google Scholar Find this author on PubMed Search for more papers by this author Published:13 July 2010https://doi.org/10.1098/rsta.2010.01001. PrologueThe compilation of this Theme Issue of Philosophical Transactions of the Royal Society on the theme of Raman spectroscopic analysis of materials from extreme environments is timely for several reasons, perhaps the most significant of these being the realization in the last decade that this technique can provide unique information about the limits of survival of biological organisms in terrestrial locations, where hitherto the prospects of finding life were thought to be minimal. The year 2009 marked the bicentenary of the birth of Charles Darwin and the sesquicentenary of the publication of his monumental work, On the Origin of Species by Natural Selection in November 1859. This book ran to six editions and it would be superfluous to comment here on the astounding debates that raged in the second half of the nineteenth century involving all aspects of arts and sciences and religion. Although today we associate Darwin’s work with evolution, it is interesting that this was only mentioned in the final and sixth edition, which also contained his first recognition of and counter argument against the claims then being made by theologians. Although Darwin himself did not have knowledge then of the extreme-tolerant, ‘extremophilic’, organisms that today we regard as ubiquitous, the analogy with the survival by natural selection of those organisms that were best suited to survive predatory attacks or environmental changes independently proposed by Alfred Russell Wallace and Darwin is quite similar in evolutionary terms to the birds, beetles and lizards that caused so much wonder from Darwin’s observations in the Galapagos Islands in the Beagle expedition of the 1830s.It is clear from the analytical data that have been obtained in recent years that the strategies being adopted by organisms in stressed environments, examples of which are tabulated in table 1, in life-threatening scenarios are critical for their survival and evolutionary behaviour. The key factors that have emerged suggest that the synthesis of particular suites of protective biochemicals that act as protectants and repair agents when damage has occurred, often in multi-functional roles, is critical for survival in these ‘limits of life’ situations. The correlation of the extreme terrestrial survival by Archaean cyanobacterial colonies that have had to adjust and evolve from a primitive and hostile Earth some 3.8 Gyr ago with the stresses of possible similar colonizations on our neighbouring planets and their satellites is now at the forefront of multidisciplinary research efforts to understand and evaluate these possibilities using unmanned planetary rovers and accompanying sensor instrumentation.Table 1.Terrestrial extremes for the survival of extremophilic organisms. Collapse temperaturePyrolobus fumarii (Volcano Island, Italy) 113°CChroococcidiopsis sp. (Mars Oasis, Antarctica) −15°Cpressure1200 barradiationDeinococcus radiodurans 5 Mrad (5000 times the fatal dose for humans)underground depth3.2 kmacidic pHpH 0.0basic pHpH 13.0longest in spaceBacillus subtilis 6 yr NASA sa