Entropy in biological systems

   This post is based on ideas I had in relationship to a (very sophisticated) website discussion on the views of England (and associated discussion through posts) of entropy and biological systems which you will find at http://www.simonsfoundation.org/quanta/20140122-a-new-physics-theory-of-life/#comment-159978

    The original state was a physical state and not a biological one until life prevailed and as such must obey all known physics rules. However the possibility exists that early organisms may have initially overcome some of the constraints of the physical universe, or at least to minimise them. This is where the concepts of England and others regarding entropy must be invoked, if not later to describe ecological systems. 
   I have been greatly perturbed by the constant use of “equilibrium” forest ecosystems etc. and it is very difficult going from the molecular, to the macro level of organisation of microbial communities or forests, but at the micro level effectively if something is at equilibrium it is dead. Kauffman described the possibility that dynamical non-equilibrium systems could be stable, which seems to me a better description for forests and other ecosystems i.e. at the macro level. Whatever consensus is eventually reached the molecular to the ecosystem level should be consistent in the final thesis. Except that we all know that Einstein/gravity and the quantum world aren’t that consistent! So do we have to await the outcome of those investigations before we assign Boltzmann to the wider world of soil bacterial communities? It seems to me that until physics resolves that dilemma it will be quite plausible to differentiate macro and micro systems, especially in the biological world which attempts to control the physical (albeit with various success levels). 
    The new theories of life based on entropy could be maligned, but then that is what was done to the chemical theory of life 50 years ago. There are coupled chemical and physical conditions which occurred when life first arose as mentioned. But life is another system which often overcomes or utilizes or improves physicochemical conditions for its own purposes. Of course it must ultimately be accountable to physics processes such as entropy and this may indeed be a driving factor in the organisation of some or most ecosystems and communities, but perhaps not in ways proposed by England and others. 
   There is still the problem of the original sentient organism though. Much investigation has been done on chemical factors involved such as the ATP system and H systems, and also on heavy metals, so that early organisms could have arisen primarily in response to chemical factors. The fundamental nutrient requirements of nascent life really needs to be clarified before we can make any estimates regarding chemical equations etc., and thus energy and entropy. The truth is we don’t really know the chemical equations, although there is acknowledgement that RNA was involved early on. Personally I think the entropy outcomes of the ADP/ATP system which is shared by all lifeforms is important.
  When life began I don’t think one could call the first precursor of the protocell an “ecosystem”, so we are definitely not dealing with the macro level there, but probably with the micro level and the equilibrium Boltzmann equations.  My view is that the early cell progenitor probably arose as a chemical system under a membrane between rock surfaces, which became coordinated to the point where it behaved as one entity and thereafter formed a more permanent membrane.  This precursor to the proto-cell must not have been singular, so that a number of such chemical “bubbles” existed.  They began to “trade” scarce nutrients with each other, although which ones were scarce is not clear, perhaps you do have a nascent ecosystem, involving entropy at the macro level.
  One thing I noted I think from  Lehninger’s biochemistry books was in regard to the excess of energy that plants have to deal with. Additionally the entire mitochondrial ATP energy system of animals is also set up to deal with exactly what the article described, dissipating energy, but not in the sense proposed. The problem is too much energy. Plants cannot deal with the amount energy provided daily, and animal mitochondria cannot either.  Both deal with this via stepped processes involving many chemical equations.  But are these two major biology energy production systems ultimately driven to produce net entropy?
   After the nascent filmy bubble of chemicals coalesced and later formed a protocell complete with RNA, they were no longer ever again purely physical. There is something of a split in science where entire systems are studied by either physical scientists or biologists noticeably in carbon chemistry where some see the problem as a purely physical/chemical study, whilst others are only interested in microbial or plant production systems. Any theory that proposes to describe life cannot be a purely physical theory as lifeforms are sentient.
    Even the most primitive bacteria has sophisticated responses, and one of these is to move away from the pipette- to survive. It is as though life is a response system to the physical environment.  Thus theories of life may incorporate mathematics and physics, including concepts such as entropy, but if the life system is a response system, it may have qualities that are unique also, and these must be incorporated into descriptions of the system e.g. sentience.  It is also dangerous to degrade the biosphere, because the physical system will then have more influence than the life system on the planet again i.e. in two interacting systems one may be more dominant. Only by maintaining biosphere resilience can we avoid the worst physicochemical excesses, and even then not always, such as in the case of earthquakes etc. so that it is clear that in spite of the life system’s best efforts, the physical system retains its dominance, at least to some extent.  This begs the question to what extent is the life system and the physical system one as in the case of Gaia, or to what extent are they two interacting systems.
   This is a question that should be answered by a similar body to international synchotrons e.g. an international Biotron. Surely the systems involved on the very planet we live on are essential for us to understand, and only then can we really understand how land-ocean-atmosphere interactions behave in the sense of climate change etc. My view is that James Lovelock was on the right track with “Gaia” but went a bit too far, and the systems are still separate but very much integrated due to life processes, so that the physical system retains less dominance than in the dawn of life.
    If life is seen as a response system, perhaps its function is to diminish entropy, and thereby increase order and complexity as described by Kauffman, not increase it.  But as I do not know if the overall results of entropy production in the ATP or photosynthesis systems are net positive or negative, which would give a clue, I can’t be sure. It is clear however that such processes in organisms create a very large amount of order, which no doubt diminishes entropy in the interim.  Self-organisation in a community or ecosystem could be in order to decrease entropy found in the physicochemical planetary environment, and this could be seen as a form of efficiency.
  In that type of scenario, organism death would be when the (body) system can no longer provide a response (literally) and when in fact entropy does increase. However this is simplistic because apostasis (cell death) appears to be some sort of necessary component of bodily systems so that cell growth (cancer) can actually cause illness and death. My final thought on this is that when watching the lion killing the buffalo, I can’t see how other than with trophic energy explanations (which was an important addition above) anyone can see too much order in that. Therefore if such a process as death is the reverse of order, it may be the mechanism to ensure that ultimately ecosystems obey thermodynamics and produce net entropy.


About ccatctc

biologist, conservationist, avid reader of scientific info, concerned about the state of the planet.

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