Evolutionary waterways: the contextual dynamics of bilogical diversity.
Popular evolutionary theory unrealistically separates "dry" inherited information from the "wet" context in which that information is processed. Consequently, the recipe for biological diversity omits a vital ingredient, water, and evolution is thought to involve purely external selection of fully discrete informational units that struggle for existence in a fixed frame of reference. A misguided, aridly dispassionate, uncompassionate belief in calculable, controllable genetic futures emerges.
A more empathic understanding arises from appreciating that evolutionary versatility results from varied patterns of assimilation and distribution of free energy in a dynamically bounded ("indeterminate") context. Here, the properties of water as a receptive medium are paramount.
Introduction: Informational Traffic and Contextual Waterways
In perhaps his most ironically titled book (1), Richard Dawkins depicts evolution as a "digital river" of DNA, "uninfluenced by the experiences and achievements of the successive bodies through which it flows" or by the "contamination" of sex. He asserts that there is "no throbbing, heaving, pullulating, protoplasmic, mystic jelly ... life is just bytes and bytes of digital information."
Such views epitomize an evolutionary perspective that devitalizes life by reducing it to fully discrete units of reproducible information--genes. These units are considered only to be capable of change through random mutation and subject to purely external selection pressure applied within fixed frames of reference where competition is the counterpart of growth, at odds with compassionate feeling.
The digital river is, however, a contradiction; a particle stream with no coherence or continuity, and hence no force or responsiveness of its own. It can only run into sand as the energies of its individual ingredients are dissipated in the resistive field of its environmental setting.
Real river systems are very different. Driven by energy input, they both create and follow shifting paths of least resistance through space and time due to interactive feedback between their ingredients and catchment. Both the topographical boundaries of their banks and regional boundaries of their watersheds, are "indeterminate"(always prone to move). (2) These boundaries define the intercommunicating contents and containers of dynamic energetic contexts that continue to open and be open to new possibilities as long as their flow is sustained by energy input.
What makes the difference between a real river and a digital river is obvious: water. Likewise, what makes the difference between real life and a sterile, digital perception of life, is water. Water brings life to life. It provides the coherence and continuity of context that has enabled genes to proliferate and diversify through evolutionary time. Its continual presence through evolutionary lineages going back to the dynamic origin(s) of life itself has sustained the flow of genetic information within indeterminate boundaries whose variable patterns of differentiation and integration generate never-ending possibilities of form and behavior. To try to understand this flow without reference to its context is like trying to understand traffic without reference to the highways that both define and are defined by the form and movement of vehicles.
We therefore want, here, to encourage a deeper appreciation of the relevance of water and its physical properties--about which more continues to be discovered (3)--in the evolution and interrelationships of life. In vital partnership with DNA, water is most fundamentally the "artist's medium" through which energy expresses itself in a life that is both wild and full of surprises for those who might presume to control or predict it. Water is also the medium in which scientific thought and artistic feeling, and many other seeming opposites, can complement rather than conflict. Within it may lie the deep reason for emotion, our responsiveness to our own and others' needful being.
The Need for a Systemic Perspective: Contextual Dynamics
What possibilities for innovation and relationship are there in a droplet of water? To understand this question fully, it is necessary to extend beyond (while encompassing) purely analytical approaches and adopt a systemic perspective based on how energy can be transferred into, within, and out of the droplet. This perspective is neither reductionistic nor holistic. Both these latter approaches imply discreteness--the one assuming the separateness of parts, the other the entirety of wholes--and so restrict awareness of possibilities because they don't allow any dialogue between the insides and outsides of their respective organizational units.
Systemically, a droplet of water can be regarded as a pool of free energy, a dynamic context whose surface-tense boundary is both a site of maximal order and a reactive interface between its inside and outside. The surface area of this boundary can be altered by assimilating or discharging energy sources.
Assimilative processes result in expansion of the boundary. At low input rates, this expansion is isotropic, minimizing the resultant increase in free surface. At higher rates, symmetry-breaking (4) occurs, so that the droplet polarizes into a rivulet or subdivides into branches that, in being both separate and connected to one another to some extent, have only a degree of freedom. At even higher rates, the droplet may dissociate into smaller droplets and ultimately molecules. Viewed as a snapshot in time, these entities may appear to be discrete individual units, but this ignores the historical trajectories that link them to a common origin. Such trajectories are only apparent when viewed within a dynamic context of space and time, where their indeterminate capacity for expansion and change reveal discreteness as an illusion.
Assimilative processes causing progressive subdivision of an initially coherent state can be termed "self-differentiation." (2,5,6) They generate increasing amounts of exposed free surface through which the system both gathers and dissipates energy. The emergence of such surface has, confusingly, been referred to as "self-organization," (7) or "order out of chaos" due, we suspect, to misinterpreting the location of system boundaries and so supposing that the surface arises from a random rather than coherent state. In fact, from a systemic perspective, chaos, in the form of the deterministic proliferation of free surface in a forced system, is a state of increased order--increased boundary, even though the connectivity of this boundary becomes progressively more tenuous. (5,6)
Since finely divided, self-differentiated systems are necessarily highly dissipative, they are only sustainable as long as large quantities of assimilable free energy sources remain available. Were self-differentiation to continue without such sources, it could only end in a boundless and hence truly random entropic state. This fate is, however, prevented by "self-integrative" processes (2,5,6,) complementary to self-differentiation, which minimize free surface by pooling boundaries into more coherent organizations. In the case of water, vapor may condense into droplets, droplets may coalesce into pools, and pools freeze into a myriad of ice forms, with a release of stored energy accompanying each reduction in free surface.
Such are the creative possibilities for differentiation and integration of form even in a droplet of pure water. Now, allow materials to be incorporated or dissolved within the droplet's contents, changing their viscosity, matric, electrical, and osmotic potential, or added to the surface of the droplet to form an insulating coating or envelope. Harnessed in this way, the dynamic potential for elaboration of diverse water forms becomes even greater, enabling their permeability, deformability, and continuity and consequent receptivity, responsiveness, and conductivity to be varied according to circumstances.
In those water forms that we have come to regard as life forms, materials added to and enveloping water constrain and enable the expression of diversity over scales ranging from the boundaries of molecular to social and ecosystem domains. These materials may be organic or inorganic. They may originate outside the life form's boundaries; they may be synthesized within, as the consequence of gene action, or they may be produced by interaction at boundaries between internal and external reagents. They include the carbohydrates, fats, proteins, nucleic acids, and other metabolites found in living cells. They include the oxidatively cross-linked hides, bark layers, cuticles, and cell walls of innumerable forms of plant, animal, and fungal life. They include the calcium-enriched shells and coatings of invertebrates and algae. They also include the earthy highways, byways, dams, and buildings created by animals ranging from termites and earthworms to moles, beavers, and human beings as they open up and seal off paths of least resistance.
Viewed in the continuous dynamic context of harnessed water, genes are not the sole agents of their own destiny, subject to random chance and environmental vicissitudes. Phenotype--outward form and behavior--is not, as genetic determinism would have it, a direct genetic function of environmental variables. Rather, genes are variables whose influence on boundary properties affects the pattern in which water is arrayed, and re-arrayed, through space and time. Life forms are not fully discrete individuals, but rather interconnective trajectories encompassing the self-differentiated and self-integrated states of life cycles and spirals produced as energy supply and demand waxes and wanes. Selection is due to unpredictable, interactive feedback between expansive and resistive processes that can both open up and close down options, much as a potter molds clay. There is no fixed frame of reference in which life forms inevitably struggle for existence. The emergence and expansion of one form of life makes it possible for others to follow within its wake or upon its foundation, just as the binding of sand dunes by marram grass makes it possible for trees to take root. Diversity both in form and scale is autocatalytic.
Fungal Mycelia: Epitomizing the Possibilities of Indeterminacy
The systemic approach to viewing life in the dynamic context of evolutionary waterways is beautifully illustrated by fungal mycelia. This is because of the way mycelia are physically organized as indeterminate, versatile systems of interconnected, water conducting tubes. These systems can span heterogeneous environments of potentially great complexity, ranging over space and time scales from micrometers to kilometers and seconds to millennia and in which energy is often in very variable supply. (5)
The versatility of fungal mycelia becomes evident as soon as a spore takes up water and nutrients, so expanding isotropically at first and then breaking symmetry with the emergence of one or more indeterminately expanding, protoplasm-filled germ tubes. Alternatively, a determinate unicellular pattern may be maintained for greater or lesser periods, as in yeasts.
Once polarity has been established, the hyphal tubes may become internally partitioned by valve-like in growths known as septa, and branch in either a tributary-like or a distributary-like pattern. The branches either diverge or converge and fuse--anastomose). Whereas some parts of the system are in close contact with the nutrient source, others become sealed off or emerge beyond the immediate sites of assimilation. The branches may remain diffuse or they may aggregate to form protective, reproductive, or migratory structures. While some parts of the system continue to expand, others degenerate.
The biological utility of such a changeable dynamic structure becomes clear whenever fungi are observed growing in heterogeneous environments. For example, in moist woodland soil, networks of mycelial cables interconnect the roots of neighboring plants as well as decaying wood or leaves. The processes leading to the formation of such networks can be revealed experimentally by growing the relevant fungi in sets of chambers that are isolated from one another with respect to diffusion through the growth medium, but interconnected by passageways that allow particular portions of the mycelium to grow between and across separate domains. Here it is possible to see how, purely by changing its boundary properties in response to local circumstances and without any central administration, a mycelium can generate a persistent network that is reinforced along avenues of successful exploration.
The special properties of mycelial networks arise from the fact that they connect boundary resistances in parallel rather than in series, as in branched systems, so increasing conductivity and reducing the tendency to self-differentiate/break symmetry. Networking enables stable "establishments" to form at the same time as allowing multiple redistributional options through a potentially huge number of sub-circuits. It also makes possible large amplifications of organizational scale as a result of the increase in waterpower, which can be delivered, to a local site of expansion or emergence--the system may literally be capable of "mushrooming." For the latter to occur, however, energy input has to exceed throughput capacity. This may be difficult for a system that automatically "self-limits" by minimizing the proliferation of assimilative boundary, but can be achieved through degenerative mechanisms. These mechanisms allow dis-integration of part of the network and consequent redistribution to outgrowth sites, as in fairy rings (8).
It is vital, however, to appreciate that such properties are by no means peculiar to fungi. Extremely similar properties are evident in the roots and shoots of many plants, in nervous systems, leaf veins, blood systems, and the trajectories of moving animals as they diverge from, converge upon, follow, and reinforce one another's riverine paths. They underlie the proliferation, consolidation, and extinction of phylogenetic pathways as species emerge, associate, and disappear. They reflect the trajectories of free thought. In short, these properties are a universal feature of dynamically bounded systems that both create and follow paths of least resistance as they differentiate and integrate.
Interacting with Earth, Fire, and Air
The dynamic interplay between self-differentiation and self-integration, epitomized by the proliferation and networking of fungal mycelia, depends fundamentally on the availability of external energy supplies ("resources"). High availability allows high input rates and consequent self-differentiation of dissipative surface (boundary-proliferation). Restricted availability leads to self-integration into coherent organizations capable of exploring for, conserving, and recycling resources, and so connecting across times/spaces of shortage between times/spaces of plenty.
Studies with fungi have helped to highlight the importance of the relationship between sources of fuel, oxygen and water in the boundary chemistry that mediates this interplay. (5) Fungi, like the majority of earthly organisms, have become addicted to oxygen as a potent but potentially dangerous source of chemical energy through its role as an acceptor of electrons passed from the earthy fuel of carbohydrates, fats, and proteins through the consuming fire of respiration. Oxygen--of which water, through the constructive light-fire of photosynthesis, is itself a source--accepts these electrons one at a time, so generating extremely reactive chemical species, including free radicals, that are only rendered innocuous once the electrons have been fully incorporated into water. Any imbalance between the supply and demand for electrons allows the reactive species to accumulate, disrupting the chemical integrity of living cells and causing degeneration. This fate can be prevented in watery environments by quenching and excreting reactive species by means of antioxidant compounds--that can then play additional roles, e.g., as antibiotics. In terrestrial environments, though, it is necessary to prevent excess oxygen entering cells from the gaseous phase, where it diffuses 10,000 times more rapidly than through water, and this is done by actually using the oxygen to produce polymeric, oxygen-impermeable coatings. These coatings change the boundary permeability and consequent pattern-generating potential of life forms that possess them. Their role in the evolution of terrestrial life is pivotal, yet has attracted little attention as an explanation for phenomena as fundamental as the heteromorphic alternation of haploid and diploid generations and origin of arborescent form in land plants. (2)
Receptive Water: a Source for Emotion
Water, then, is the medium into which and through which life forms receive and distribute energy. It enables life forms to be both sensitive and responsive, diversifying in times of wealth and coming together in times of need, avoiding growth beyond their means. But perhaps its significance is even deeper, extending or transcending the boundaries of the strictly scientific. In dreams and myths it symbolizes the unconscious, the female and the natural, compassionate, spontaneous self that comes, stays, and goes wherever it will. (9) In its reflection can be found a route to contemplative introspection and repose. In its disturbance can be found turbulence. What better place to look for a reason for emotion--a source of nurture in nature? Is it a coincidence that we refer to our boiling, bubbling, flat, frothy, floating, drifting, drowning feelings in watery terms, that we release watery tears when experiencing extremes of sorrow and joy, and attribute bodies of water with anger and calm? But water was present before our consciousness of these feelings. Perhaps when we regard ourselves and others, we are water reflecting upon itself, capable both of unconditional love and of alienation depending on the state of our dynamic boundaries.
Conclusion: Dynamic Water, Dynamic Context
The dynamic need of life for water is obvious, so obvious that it is usually taken for granted. It is neither explored in its full depth nor celebrated other than in a few dismissive words at the beginning of elementary biology textbooks before moving on to the nitty-gritty of adaptive mechanisms. Perhaps in consequence, the importance of water is usually recognized in terms of how it enables life to exist at any one time, as a habitat, a solvent, a chemical reagent, a support, or a circulatory fluid. There is much less awareness of how water has enabled life to change and be changed by its dynamic context, and will continue to do so as long as our planet doesn't become deserted. As artists know only too well, a medium is so much more than just a solvent.
(1.) Dawkins, R. (1995). River out of Eden. London: Weidenfeld & Nicolson.
(2.) Rayner, A.D.M. (1997). Degrees of freedom--living in dynamic boundaries. London: Imperial College Press.
(3.) Smith, C. W. (1998). Is a living system a macroscopic quantum system? Frontier Perspectives, 7(1),16-23.
(4.) Stewart, I. and Golubitsky, M. (1992). Fearful symmetry: is God a geometer? Oxford: Blackwell.
(5.) Rayner, A.D.M., Watkins, Z. R.,and Beeching, J. R. (1999). Self-integration--an emerging concept from the fungal mycelium. In N.A.R. Gow, G. M. Gadd, and G. Robson, (Eds), The fungal colony. Cambridge University Press.
(6.) Rayner, A.D.M. (1997). Evolving boundaries: the systemic origin of phenotypic diversity. Journal of Transfigural Mathematics, 3(2), 13-22.
(7.) Prigogine, I. and Stengers, I. (1984). Order out of chaos. London: Heinemann.
(8.) Davidson, F. A., et al. (1996). Context-dependent macroscopic patterns in growing and interacting fungal networks. Proceedings of the Royal Society of London, series B, 263, 873-880.
(9.) Godwin, M. (1994). The holy grail--its origins, secrets and meaning revealed. London: Bloomsbury.
Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K. E-Mail: A.D.M. Rayner@bath.ac.uk
1 Foxcombe Road, Bath BA1 3ED, U.K.
|Printer friendly Cite/link Email Feedback|
|Author:||Rayner, Alan; Way, Caroline|
|Date:||Sep 22, 1999|
|Previous Article:||Response of physiological parameters to low frequency and low intensity pulsed magnetic fields.|
|Next Article:||Gravity as a wave phenomenon.|