This article is supplemental to “Genes and the Central Fallacy of Evolutionary Theory”, and should be read in conjunction with that essay. Both pieces are part of a larger work in progress entitled: Toward a Biology Worthy of Life. Original publication of this article: February 28, 2013. Date of last revision: March 6, 2013. Copyright 2013 The Nature Institute. All rights reserved.
There is no single seat of power in the organism. Its living dynamism is reflected in a fundamental polarity exhibited by every living thing — a polarity involving the interpenetration of, and creative tension between, two principles: on the one hand, relatively fixed structure and organization; on the other, plastic energies. Samuel Taylor Coleridge spoke of an irreducible polarity between "confining form" and "free life" (cited in Barfield 1971, p. 31*), and it is indeed impossible to have life without structure, identity, and already achieved form, just as it is is also impossible to have life without movement, flexibility, and change.
Neither pole can ever be absolute, and each requires the other in order to be itself. We couldn’t speak of limitation or confining form if there were no energy to limit or confine; at the same time, free movement requires a more fixed element as a resistance to work against. Or, in slightly different terms: form or structure without free movement would be a crystalline death, while free movement without structure would be meaningless chaos.
The gestural language of our bodies depends upon this polarity. The ballet dancer could express nothing, just as none of us could even stand upright and walk, if our flexible muscles did not have the resistance of our bones to work against. Much the same is true of facial gestures as well as the vocal organs through which we form audible gestures. Our blood could not flow properly without the constraining channels of artery and vein. At a lower level of observation we see a similar tension displayed in the relation between relatively plastic stem cells and the more defined end-products of cell differentiation.
And lower still: the field of protein research, long dominated by the search for static, crystal-like structures, has been revolutionized by the realization that protein molecules are not in general folded so fixedly. Not only are dynamic, conformational changes common, but “intrinsically disordered” or “unstructured” regions play a vital role in many proteins. This understanding, according to structural biologist Peter Tompa (2012*), would have been “pure heresy” a little more than ten years ago. But “the evidence for the generality and importance of [the intrinsically disordered state] is now so insurmountable that it demands the inclusion of ‘unstructural’ biology into mainstream biology and biochemistry textbooks”.
Not that “disorder” is really the best term. “Flexibility” or “plasticity” might be better; the less structured regions of a protein are crucial to the potential for contributing to appropriate structure in a context-dependent manner. This is why regulatory, signaling, and “hub” proteins — proteins at the center of complex molecular interaction networks — are especially rich in disordered regions. Their flexibility makes them adaptable to a broad range of structural “matings” with other, perhaps more rigidly structured proteins.
Or, again, there is the cell membrane (plasma membrane). It bounds and gives form to the cell, thereby helping to preserve the cellular identity. But it counters this fixity by also serving as a platform for exchange between the interior of the cell and its “social” context. Messenger molecules from outside, in communicating with membrane-associated molecules, trigger signaling cascades directed inward from the membrane (often toward the nucleus in order to carry out gene-regulatory functions), and at the same time the cell exports through the membrane its own “signals” for pick-up by its neighbors. The cell, with the help of its membrane, maintains a balance between preserving self-identity and responding to the unpredictable flux of the environment (Grecco et al. 2011*).
As a last example of a rather different sort: the flourishing of tissues through cell proliferation, cell growth, and cell migration depends upon the ultimate loss of “free life” — namely, cell death. It was discovered several years ago that dying cells put out “signals” required by surrounding healthy cells for growth and proliferation. Just as death and decay on the forest floor are prerequisite for new life, so, too, in the tissues of our bodies.
It happens that naked DNA lies toward one of the poles we are speaking of. Removed from its enlivening context, it comes about as close to being inert and crystalline as anything in our bodies. But this character is counterbalanced by all those fluid processes, continual molecular exchanges, and dynamic rhythms through which chromosomes are modified and brought into productive movement And so we can think of the double helix as providing a structure of relative inertness and rigidity that becomes a playing field for the more plastic potentials of the organism — rather as the abstractly defined words of a dictionary (which, merely as given, would make communication nearly impossible) are brought alive through the fluidly shifting, contextually supported meanings of living speech.
Life arises through a thousand examples of this interplay between limiting structure and free response. The interplay, not one pole or the other, is what counts. We see an interactive unity resulting from the creative tension of an essential, living, polar dynamic. There is certainly no basis for claiming more information or meaning in relatively rigid structures than there is in relatively free flows. If one pole were to be considered the primary one (although never absolutely so), it would have to be the pole of plasticity, flexibility, and flow. In the organism — and this is particularly evident during embryonic development — the general rule is that flow precedes and shapes fixed structure (Talbott 2002*).
One further note. There is a temporal aspect to this polar tension, related to a common observation about the development of organisms: they possess a certain flexibility and adaptability in the face of perturbations — as when (to take a case of artificial manipulation) researchers excise a group of cells in a young embryo and transplant them to a different location. The organism may then adapt the cells to their new location, changing their destiny. We see an equally impressive response to insult in those organisms capable of regenerating severed limbs.
But this bodily adaptability shifts toward the opposite pole over the course of a lifetime. We can see the shift in the changing dialogue between what we might call the principle of renewal and that of decay, both of which are essential to the organism. The dramatic transformation of organs during embryonic and later development would be impossible if cells were not continually dying off, leaving space for the remolding achieved by newly born cells. The overall impression left by this polar dialogue in the young organism is one of thriving, developing, ever-renewing life. As the organism ages, however, it tends to become stiffer, less flexible, more “fixed in its ways”, at least physically. Death, of course, brings the ultimate rigidity — and an exit from the polar dynamic of life.
This, too, points to the fact that the primary pole of life is that of plasticity, even if it engages in necessary dialogue with a more death-like fixity. The long-running fascination of biologists with the supposedly unchanging linear sequence of DNA as if it were the “Book of Life” was an aberration — almost the antithesis of reality.
Barfield, Owen (1971). What Coleridge Thought. Middletown CT: Wesleyan University Press.
Grecco, Hernán, Malte Schmick and Philippe I. H. Bastiaens (2011). “Signaling from the Living Plasma Membrane”, Cell vol. 144 (March 18), pp. 897-909. doi:10.1016/j.cell.2011.01.029
Talbott, Stephen L. (2002). “On Being Wholehearted”, NetFuture #140 (Dec. 26).
Talbott, Stephen L. (2010). “Getting Over the Code Delusion”. Latest version and a brief summary are available http://natureinstitute.org/txt/st/org/index.htm#delusion
Tompa, Peter (2012). “Intrinsically Disordered Proteins: A 10-Year Recap”, Trends in Biochemical Sciences vol. 37, no. 12 (Dec.), pp. 509-16. doi:10.1016/j.tibs.2012.08.004
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Steve Talbott :: Free Life and Confining Form