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What do we think life is? A simple illustration and its consequences

Published online by Cambridge University Press:  06 September 2013

William Bains
William Bains*
Affiliation:
EAPS, MIT, Cambridge, MA, USA SENS Research Foundation Laboratory, Chemical Engineering and Biotechnology, Cambridge CB2 1QT, UK e-mail: bains@mit.edu
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Abstract

The conundrum of finding a ‘definition’ for life can be side-stepped by asking how people actually identify examples of life, and using this as the basis for life detection strategies. I illustrate how astrobiologists actually select things that are living from things that are not living with a simple exercise, and use this as the starting point to develop four characteristics that underlie their decisions: highly distinctive structure (physical or chemical), dynamic behaviour (physical or chemical), multiple instances of life forming a ‘natural group’ and that the structural and dynamic characteristics of the group are independent of the details of the substrate on which life is growing. I show that these all derive the role of a code in the dynamic maintenance and propagation of life. I argue that evolution is neither a useful nor a practical way of identifying life. I conclude with some specific ways that these general categories of the observable properties of life can be detected.

Keywords

definitiondetectionkey featureslife
Type
Research Article
Information
International Journal of Astrobiology , Volume 13 , Issue 2: Special issue: Fifth UK Astrobiology Conference (ASB5) , April 2014 , pp. 101 - 111
Copyright
Copyright © Cambridge University Press 2013 

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