A new perspective by Sara Walker and Leroy Cronin titled "Beyond Prebiotic Chemistry" is available in this week's issue of Science. The perspective explores the dynamic properties of networks that might be necessary for the emergence of the living state, and proposes that uncovering ``laws of life'' might be necessary to solving its origins. The full text is available from Science.
8/12/2016 06:37:00 am
It's a nice idea and we certainly do need to think beyond the particular chemistry that constitutes life as we know it here on earth. This life is already the result of at least two 'singularities': choices made in a highly non-ergodic system that make the particular history important (i.e. not all states are accessible after the choice is made). However, we should not get carried away with abstraction (I believe) since, As Leroy and Sara correctly say near the beginning of their article, unless there is some way to hold the concentration, interactions will disappear through difusive dispersion. Therefore, I think that a key feature of general living systems, missing from their agenda, is the 'tegument' or boundary. This is an explicit part of the definition of an autopoietic system (Maturana, H. and Varela, F. J. 1980) and the theme of Pier Luisi's group (see http://www.plluisi.org/). I would therefore refer to a *bounded* autocatalytic set that is capable of innovation. I think it is also worth noting that information (in the (Kolmogorov rather than Shannon sense) is distributed throughout the network and that its ability to selectively interact with its environment (on its own terms - cognition as Varela puts it) is an information process particular to life. This and the ability to innovate are both a consequence of information abstraction (see Walker 2014) and it is this abstraction that gives life its apparently unique property of autonomy in action (that is living things alone seem to be the source of their own actions). To understand that, we need the ability to quantify information abstraction (whereby cause and effect is replaced by signal and response). I think this will specify the difference between a general autopoietic system and a living one. In the abiotic universe, everything is rigidly connected by chains of cause and effect (with randomness introduced by quantum effects). Living systems partially isolate themselved from this: their responses to environmental circumstances are internally generated and depend more on their previous (evolutionary) history. I think that is a good place to next focus research. Clearly, I agree with the authors that profound answers are to be gained from an information-based study of life in gerenal terms.
5/27/2021 08:03:21 pm
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Sara Imari Walker