ConradDJ said:
Concepts like equilibrium and dissipative structure are indeed relevant to most categories of physical order. But they are fundamental only at a certain level. Specifically – the laws of physics make it natural for many kinds of systems to arise that recreate their own structure again and again over time. A planetary orbit is the simplest example, though here the concept of equilibrium doesn’t yet apply – if an orbit is perturbed there is no tendency for it to return to a previous state. A star is an example of a system that does maintain an equilibrium-state through opposing forces of gravitation and nuclear fusion. In this kind of dissipative structure, many perturbations can easily be absorbed – but if this kind of system is pushed beyond a certain limit, it fails and will never recover equilibrium.
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Quite true. But I am trying to go beyond these everyday imperfect examples to extract the general truths. So we actually want to forget all the local particulars which hide the deeper principles.
This has been one of the problems in the development of hierarchy theory I have argued. The urge to include unnecessary details.
But there is something that is deeply counter-intuitive in my approach, agreed. The normal idea of dissipative structure is as a closed and stable system transacting energy. So you have a cell that takes in stuff at one end and pushes it out the other. The cell itself stays the same size. Likewise a star. A balance of gravity and fusion, it stays the same size by varying its burn rate.
But I instead am thinking about systems like scalefree networks and universes which instead are dissipatively expanding, not statically transacting. A big difference, though thermodynamically the same second law applies.
So a universe, in effect, is making its own heat sink. The expansion of spacetime is paid for by the cooling of spacetime. This is more like a star than a cell because it is more freely self-organising. A cell has to construct its walls, a star just collapses to a balance point. And a universe just freely expands and cools.
It is all about removing the constraints until you have a hierarchy as naked as possible.
ConradDJ said:
Once a self-replicating system is established, we have a completely new kind of possibility-generating dynamic. Each organism by itself is a complex of self-equilibrating chemical systems, that can maintain itself over time or else fail and die. But the failure of individual organisms to survive and reproduce is the basis of “selection”, which plays a necessary constructive role in the evolutionary process. This is completely new.
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True, true, true. But again, this is the very familiar story of complexity, and I am talking about a hierarchy theory approach to simplicity as well - that is where the novelty lies.
I was for many years very focused on issues of complexity. And it was a big surprise to find that the same systems logic - stripped to its fundamentals - would seem to give a view of the origins of simplicity as well. I shifted track to this new area of study. But I don't deny my original one.
ConradDJ said:
As you say, biological evolution evolves constraints that channel homeostatic processes. But it’s not as though some system invented the possibility of imposing constraints on itself! The constraints come from the new "requirement" of self-reproduction.
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The evolvability of species has in fact itself evolved. Bacteria for example will exchange RNA at any time with any species (OK, within limits, but in handwaving way...). So this is quite unconstrained. Then higher levels of biotic complexity gradually tightened the moment of genetic experimentation and the choice of partner. We have fruit flies doing little mating dances and copulating/laying eggs. Genetic variation in each new generation is a highly constrained matter, compared to the very random bacterium.
Interesting to think how many replicational constraints the human species is now removing to create its new freedoms.
ConradDJ said:
And equilibration is now playing a secondary role. The primary biological dynamic is a one-way process that improves the homeostatic efficiency of organisms as a means of improving their reproductive success, and adapts the species to a given physical environment for the same reason.
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In populations, genes form equilbriums. There is coming and going and a resulting gaussian distribution - the definition of equilbrium. Same in ecosystems. Species come and go, and there is no great
change in entropy throughput overall.
There may be some progressive trend in the history of life towards richness, complexity, entropy throughput, but it is perhaps surprisingly weak. Major steps forward would have to depend on new breakthroughs, like photosynthetic pigments early on, mitosis, somewhat later, grammatical language very recently. Then we see punctuations in the evolutionary equilbrium!
ConradDJ said:
Once life gets going, this species-level evolutionary process itself begins to evolve. Since the physical environment changes over time, there is a selective advantage for species that evolve more effectively than others. As species become more and more interdependent, this co-evolutionary dynamic becomes more important, and the evolutionary process itself starts to evolve more and more rapidly – in the emergence of sexually reproducing species, the emergence of flowering plants, etc.
So there are stages in which one level of order emerges “naturally” from a previous level – as homeostatic systems arise naturally in any complex physical environment, or as ecological structures of inter-species dependency emerge naturally once life begins to proliferate.
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So we agree generally. But I think I am making the point that major game-changing advances are more random and unpredictable than natural and automatic - steps just waiting to be found.
Another problem with life is that it exists in a dynamic context - shifting tectonic plates, variable sun brightness, wobbly Earth orbit, asteroid smashes - so this would obscure any natural path of innovation that did exist.
However, I myself would argue that there is a deep natural path to be seen if we drill down a few levels to that of a succession of increasing dimensional constraints. So as I mentioned, I think, the innovation of serial codes - OD symbols on a 1D line - is this kind of deep structure, the explanation of the causal power and dramatic shifts that occurred with genes, then words.
So there is something for sure in this search for a progressive tendency. But that is why you need a hierarchy theory approach stripped right down to raw geometry really.
ConradDJ said:
Now each stage takes up and incorporates the fundamental structures of previous stages. At every stage of evolution there are new kinds of self-equilibrating processes, e.g. in economics... new kinds of “gradients” and “dissipative structures”. That means that hierarchy theory can indeed find instances of its basic principles almost everywhere. But the fact that homeostatic equilibrium is a more generally applicable concept than reproduction doesn’t make it more fundamental as an explanatory principle, when it comes to biology.
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And this is the value of dichotomistic logic. It does not force us to chose one or the other as more fundamental. Instead it forces us to chose both as equally fundamental.
So homeostasis = innovation. Stasis = flux.
This is explicit in the MR (metabolism and repair) systems approach of Robert Rosen - the doyen of recent mathematical biology. See...
http://www.people.vcu.edu/~mikuleck/PPRISS3.html
ConradDJ said:
Philosophically, my personal proclivity is to emphasize the unique, the breakthroughs to a new level of possibility. I think there is an overarching “logic” to the way new possibility-structures have emerged in the world, but I don’t think concepts like equilibrium are adequate, even as metaphors. The “logic” needs to include both the “natural” emergence of new kinds of structure over time, within given constraints, and unique events (like the origin of the universe itself?) that in certain special contexts can create a whole new ball game, making accidents meaningful in new kinds of relationships.
Perhaps I have persuaded you that it is one-sided to have such a preference - either for what changes/progresses, or what stays the same. You need both these things to have anything - simple or complex.
The unique can only exist with the context of the general. But a holistic model would model both and not expect to construct the world merely by reference to the unique.
And a last comment on placing progressive tendencies and complexity on a pedestal. In the long run, the second law wins. Destiny is heat death. So simplicity is there at the start and there again at the end. And globally, slice the universe at any moment along the way and it has to be at equilibrium, regardless of whether it is all the simplest kind of equilibrium, or whether as now, around about the middle of its history, that simplicity is seasoned with a small dash of complexity.
Remember that the cosmic background radiation constitutes most what exist so far as the universe is concerned. The rest is just a few percent at best.
http://www.mso.anu.edu.au/~charley/papers/LineweaverEgan2008v2.pdf