Re: Metabolic closure in (M,R)-systems

[Judith Rosen <***>]

Hi Athel,

What was the title of the paper you cited?

On page 261 of Essays on Life, Itself:
Robert Rosen wrote: "I devised a class of relational cell models called (M,R)-Systems (M for metabolism, R for repair). The idea behind these systems was to characterize the minimal organization a material system would have to manifest or realize to justify calling it a cell. It seemed natural to do this; the cell is important in biology, elevated into a basic reductionistic unit by the cell theory. Yet so many different kinds of things, from bacteria to neurons, are called cells that, if this terminology is to be meaningful at all, it cannot have an exclusively material basis.

It seemed to me (and still does) that one would not call a material structure a cell unless its activities could be partitioned into two classes, reflecting the morphological partition between nucleus (genome) and cytoplasm (phenome), and the corresponding functional partition between what goes on in cytoplasm (the M of the system) and what goes on in the nucleus (the R)."

On page 203 of Anticipatory Systems:
Robert Rosen wrote: "The (M,R)-Systems represent another class of relational metaphors, this time developed within the more restricted confines of the biology of cells.

The point of departure for these ideas lies once again in this fact; that although the biologists can recognize many different kinds of cells, which may differ from one another more or less radically in physical terms, there are certain invariant commonalities which allow them all to be recognized as cells. As before, we can discern that these commonalities must be expressed in terms of biological qualities, and that these in turn must be defined on a class of systems, rather than on single ones. Once these are characterized and the linkages between them determined, we will have at our disposal a relational  characterization of all cells. From such a characterization, we will be able to understand what cellular properties follow from cellularity per se, and which devolve upon the specific physical features of particular realizations.

Two basic biological qualities play the fundamental role in characterizing our class of systems. The first of these may be crudely summed up in a single word; metabolism. However much individual specific cells differ from one another in chemical constitution, they are alike in that they are open systems, capable of ingesting and processing environmental materials, and converting them into new forms. The second of these qualities may roughly be called repair. It has to do with the utilization of processed materials to reconstitute the specific machinery by which metabolic processing occurs. Speaking very crudely, metabolism corresponds to cellular activities which are collectively called cytoplasmic, while repair corresponds to cellular activities generally called nuclear or genetic. We shall call a system capable of both these activities, linked to one another in a specific way, an (M,R)-System."

He goes on to develop one of those mathematical contexts that you are looking for, in the ensuing pages.

I'll see what else I can find for you.

Judith

Web address: http://www.rosen-enterprises.com
BioTheory: An electronic journal of general science based on the Relational (Rosennean) Complexity Paradigm
On Sep 8, 2005, at 11:25 AM, Athel Cornish-Bowden wrote:

> Judith wrote:
>
> > My only real quarrel with the paper is that it states as fact certain things that are merely opinion, with regards to more than just the perceived  deficiencies of Robert Rosen's own development of the "(M,R)-System" model. Among these opinions is the one stating that this model is purely a model of metabolic networks. My father would argue that ...
>
> Well maybe he would (anyone can change their view over the years), but we were basing what we said on what he actually did write, not on anything he may have said in private conversations. In Bull. Math. Biophys. 20, 245 (1958), he wrote:
>
> > Introduction. An important aspect of the activities of an organism for which we would like to account may be summed up in the word "metabolism". Speaking very roughly, the metabolism of an organism may be visualized as a sequence of operations whereby a set of materials drawn from the environment (which we shall term input materials) are transformed into a new set of materials (output materials) which are directly utilized by the organism in some fashion.  The study of this sequence of operations is one of the fundamental problems of biology.
>
> This seems to us to mean that what Robert Rosen meant by an (M,R) system and by metabolism is what we meant by them in our paper.
>
> It's probably also worth mentioning that we were aware (and said so) that Robert Rosen's work extended over many more domains (the modelling relation, the problems of the newtonian paradigm, the need for a new epistemology, complexity, etc.) than we touched upon in the paper.
>
> athel
>
>
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> --
> Athel Cornish-Bowden
> ***
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