Hostname: page-component-78c5997874-j824f Total loading time: 0 Render date: 2024-11-08T05:11:34.926Z Has data issue: false hasContentIssue false
  • English
  • Français

On the origin and evolution of life in the Galaxy

Published online by Cambridge University Press:  01 October 2010

Michael McCabe  and
Holly Lucas
Michael McCabe*
Affiliation:
Department of Mathematics, University of Portsmouth, Lion Terrace, Portsmouth, Hants P041 3HF, UK
Holly Lucas
Affiliation:
Department of Mathematics, University of Portsmouth, Lion Terrace, Portsmouth, Hants P041 3HF, UK
*
e-mail: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

A simple stochastic model for evolution, based upon the need to pass a sequence of n critical steps is applied to both terrestrial and extraterrestrial origins of life. In the former case, the time at which humans have emerged during the habitable period of Earth suggests a value of n=4. Progressively adding earlier evolutionary transitions gives an optimum fit when n=5, implying either that their initial transitions are not critical or that habitability began around 6 Ga ago. The origin of life on Mars or elsewhere within the Solar System is excluded by the latter case and the simple anthropic argument is that extraterrestrial life is scarce in the Universe because it does not have time to evolve. Alternatively, the timescale can be extended if the migration of basic progenotic material to Earth is possible. If extra transitions are included in the model to allow for Earth migration, then the start of habitability needs to be even earlier than 6 Ga ago. Our present understanding of Galactic habitability and dynamics does not exclude this possibility. We conclude that Galactic punctuated equilibrium, proposed as a way round the anthropic problem, is not the only way of making life more common in the Galaxy.

Keywords

critical evolutionary transitionsEarth migrationevolutionGalactic Habitable ZoneGalaxyhabitabilityorigin of lifestochasticmathematical model
Type
Research Article
Information
International Journal of Astrobiology , Volume 9 , Special Issue 4: Special issue Papers from the Astrobiology Society of Britain Conference 2010 , October 2010 , pp. 217 - 226
Copyright
Copyright © Cambridge University Press 2010

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Barrow, J.D. & Tipler, F.J. (1986). The Anthropic Cosmological Principle. Oxford University Press, Oxford.Google Scholar
Burchell, M.J. (2006). W(h)ither the Drake Equation? Int. J. Astrobiol. 5, 243–250.CrossRefGoogle Scholar
Carter, B. (1983). Phil. Trans. R. Soc. Series A 310, 347–363.Google Scholar
Carter, B. (2008). Int. J. Astrobiol. 7, 177–182.CrossRefGoogle Scholar
Cirkovic, M.M., Vukotic, B. & Dragicevic, I. (2009). Astrobiology 9(5), 491–581.CrossRefGoogle ScholarPubMed
Cohen, B.A. et al. . (2000). Support for the lunar cataclysm hypothesis from lunar meteorite impact melt ages. Science 290, 1754–1755.CrossRefGoogle ScholarPubMed
Del Peloso, E.F. (2005). Astron. Astrophys. 440, 1153.CrossRefGoogle Scholar
Flambaum, V.V. (2003). Astrobiology 3, 237–239.CrossRefGoogle Scholar
Frebel, A. (2007). Astrophys. J. 660, L117.CrossRefGoogle Scholar
Gonzalez, G. et al. . (2001). The Galactic Habitable Zone: Galactic chemical evolution. Icarus 152, 185–200.CrossRefGoogle Scholar
Gonzalez, G. (2005). Orig. Life Evol. Biosph. 33, 555.CrossRefGoogle Scholar
Hanson, R. (1998). Must Early Life Be Easy? The Rhythm of Major Evolutionary Transitions. http://hanson.gmu.edu/hardstep.pdf.Google Scholar
Haywood, M. (2009). Mon. Not. Roy. Astron. Soc. 388(3), 1175–1184.CrossRefGoogle Scholar
Lépine, J.R.D., Acharova, I.A. & Mishurov, N. (2003). Astrophys. J. 589, 210–216.CrossRefGoogle Scholar
Lineweaver, C.H., Fenner, Y. & Gibson, B.K. (2004). Science 303, 59–62.CrossRefGoogle Scholar
Martin, W. et al. . (2008). Hydrothermal vents and the origin of life. Nature Rev. Microbiol. 6, 805–814.CrossRefGoogle ScholarPubMed
Mattson, L. (2009). On the existence of a Galactic Habitable Zone and the origin of carbon. Swedish Astrobiology Meeting, Lund, http://videos.nordita.org/conference/SwAN2009/Mattsson.pdf.Google Scholar
Maynard Smith, J. & Szathmary, E. (1995). The Major Transitions in Evolution. Oxford University Press, Oxford, ISBN 019850294X.Google Scholar
Melosh, H.J. (2003). Exchange of meteorites (and life?) between stellar systems. Astrobiology 3(1), 207–215.CrossRefGoogle ScholarPubMed
Napier, W.M. (2004). A mechanism for interstellar panspermia. Mon. Not. Roy. Astron. Soc. 348(1), 46–51.CrossRefGoogle Scholar
Prantzos, N. (2008). Space Sci. Rev. 135, 313.CrossRefGoogle Scholar
Rivkin, A.S. & Emery, J.P. (2010). Detection of ice and organics on an asteroidal surface. Nature 464, 1322–1323.CrossRefGoogle Scholar
Roškar, R., Debattista, V.P., Quinn, T.R., Stinson, G.S. & Wadsley, J. (2008). Astrophys. J. 684, L79–L82.CrossRefGoogle Scholar
Schilbach, E., Roeser, S. & Scholz, R.D. (2009). Astron. Astrophys. 493, 27.CrossRefGoogle Scholar
Treeman, A.H. et al. . (2000). The SNC meteorites are from Mars. Planet. Space Sci. 48(12–14), 1213–1230.CrossRefGoogle Scholar
Valley, J.W. et al. . (2002). A cool early Earth. Geology 30, 351–354.2.0.CO;2>CrossRefGoogle Scholar
Wallis, M.K. & Wickramasinghe, C.R. (2004). Interstellar transfer of planetary microbiota. Mon. Not. Roy. Astron. Soc. 348(1), 52–61.CrossRefGoogle Scholar
Ward, P.D. & Brownlee, D. (2000). Rare Earth: Why Complex Life is Uncommon in the Universe. Copernicus Books, New York (Springer, Verlag), ISBN 0-387-98701-0.CrossRefGoogle Scholar
Watson, A.J. (2008). Astrobiol. J. 8, 1–11.Google Scholar
Wesson, P.S. (2010). Panspermia, past and present: Astrophysical and biophysical conditions for the dissemination of life in space. Space Sci. Rev. DOI: 10.1007/S11214-010-9671-x.Google Scholar