A novel chemoton model for the emergence of self-maintaining systems

Understanding how life emerged on earth is arguably one of mankind’s most fundamental questions. Having been with us in scientific terms for several centuries without solution it is clearly a challenging problem. New ideas are needed, and one of these places emergent behaviour as a central idea. All life as we know it, exhibits emergent behaviour in that living things are, chemically speaking, far from equilibrium with their environment and are maintained as such by a flow of energy and materials (food).

 

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Hveradalur lake geothermal field, Kverkfjoll mountains, Iceland (Field expedition, June 2011).

 

However, trying to build a model of what constitutes a living system is not easy as emergent behaviour is also present within non-living natural environments, such as volcanoes, fire and the shapes of sand dunes on a beach. In the 1970’s however Chilean & Hungarian scientists proposed complementary models for the most primitive of living systems and it is the “chemoton” model of Hungarian chemical engineer Tibor Ganti that is most relevant here. Ganti proposed that the basic model of a living entity (chemoton) comprised three interconnected chemical cycles, one to synthesise the membrane of the organism, another for synthesising all the chemicals needed to maintain the organism and a third for controlling which chemicals are produced. However, what is needed to power such a chemoton is a bioenergetic chemical cycle which, whilst inherent in Ganti’s model, has not previously been highlighted definitively.

 

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Boiling acid mud-pots. Hveradalur lake geothermal field, Iceland.

 

We propose here a novel chemical evolutionary mechanism for the emergence of such a system of membrane-bound bioenergetics, based on phosphorus compounds ubiquitous in contemporary biochemistry (eg: adenosine triphosphate, ATP). In exploring the feasibility of this mechanism, we will also consider how such a system could have emerged from early earth geological environments such as anoxic geothermal fields (such as are common in Siberia, California & Iceland, the latter for which we have recent experience of relevant field work –  see images) recently considered as possible cradles of early life.

Dr Terence P Kee
University of Leeds


Terence was awarded a Research Project Grant in March 2012; providing £166,816.