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Into the Cool, Part III, Chapter 11
Thermodynamics and Life

   

I like to compare evolution to the weaving of a great tapestry. The strong unyielding warp of this tapestry is formed by the essential nature of elementary non-living matter, and the way in which this matter has been brought together in the evolution of our planet. In building this warp the second law of thermodynamics has played a predominant role. The multi-colored woof which forms the detail of the tapestry I like to think of as having been woven onto the warp principally by mutation and natural selection. While the warp establishes the dimensions and supports the whole, it is the woof that most intrigues the aesthetic sense of the student of organic evolution, showing as it does the beauty and variety of fitness of organisms to their environment. But why should we pay so little attention to the warp, which is after all a basic part of the whole structure? Perhaps the analogy would be more complete if something were introduced that is occasionally seen in textiles—the active participation of the warp in the pattern itself. Only then, I think, does one grasp the full significance of the analogy.”

Harold F. Blum

Life is a terrible and beautiful process deeply tied to energy, a process that creates improbable structures as it destroys gradients. Like nonliving vortex and convection structures, the systems of life cycle materials in regions of energetic excess; by existing, and persisting, local gradients are degraded and, as in the Tornado in a Bottle, they are degraded more effectively than would otherwise be the case. But like BZ reactions spinning out spellbinding patterns, life's systems are not just physical but chemical; and with the appearance of transcription over 3.5 billion years ago in what scientists call the primordial soup, stable means of degradation evolved, allowing three-dimensional nanotechnological copying to go on. Transcription, the copying of DNA into RNA, let life grow fancy protein systems, bodies. At the same time the information to do so replicated. These events allowed the chemical degraders of life the opportunity to persist as gradient reducers beyond the time of their own inevitable entropic decay. The spread of metastable reproducing cells, open systems organizing themselves and their immediate environment, trading gases and evolving ecosystems, was to push the entire biosphere away from thermodynamic equilibrium. Today we live on a planet whose surface is not in equilibrium, but energized, producing heat and pollution in its wake. The character and possibilities of life, not only as a planetary biological phenomenon, but also on the scale of our individual lives, cannot be properly appreciated without a working knowledge of the ways of energy. Yet as a scientific discipline, the thermodynamics of life—a subdiscipline of nonequilibrium thermodynamics—remains esoteric within science and virtually unknown to the public.

Lotka explicitly includes energy in his Darwinian analysis. Organisms struggle not only for food and habitat, but for the energy that drives their material organization—their metabolism, reproduction, and expansion. Populations grow to take advantage of energy sources, enlarging flow regimes. Increased flow leads to increased material cycling. Imagine a geneticaly engineered corn variant that produces two crops rather than a single crop of corn per year. Neither the acreage of land under cultivation nor the biomass in the field will necessarily change, but the system accelerates due to the increased output of corn. A system can expand by enlarging a wheel, spinning it faster, or both.

In every instance considered natural selection will so operate as to increase the total mass of the organic system, to increase the rate of circulation of matter through the system, and to increase the total energy flux through the system, so long as it is presented an unutilized residue of matter and available energy [exergy] . . . Evolution in these circumstances proceeds in such a direction as to make the total energy flux through the system a maximum compatible with the constraints.

Those beings that best access, store, and deploy energy, or the informational means to do so at a later date, prosper. We are children of the sun, continuously transforming its energies, already transformed by photosynthetic and other life-forms, into ourselves. We are genetically organized energetic legacies. Over time, as more energy is transformed by way of living processes, the total mass of the organic system increases. This is called growth.

Lotka's energy-based perspective cut through the conceptual dividing line between life and nonlife, and between humans and the biosphere.

Jeffrey Wicken references Immanuel Kant's 1790 description of life in The Critique of Judgment. "I see now no way to dodge the Kantian challenge," Wicken writes.

In Kant's conception, an organism was a "natural purpose," in which each part and process was jointly cause and effect, end and means, of the operation of the whole. This remains an extremely useful definition. First, it states explicitly the circularity of biological causation and teleonomic organization with which any theory of emergence must come to terms. Second, it can be brought readily into the framework of contemporary science in a way that makes contact with the ecological identity of organisms. In this definition, Kant had pithily captured the concept of informed autocatalysis. A "natural purpose" is an informed autocatalytic system or AO—a system with an internal organization of kinetic relationships able to maintain itself by pulling environmental resources into its own production. The fact that an organism behaves as its own end and means through participation in the dissipative flow of nature suggests a deep connection between self-organization and the Second Law.

Organisms may be seen as connectable nodes that transform the environment as they mediate energetic flows. An airborne retrovirus that quickly destroyed the human population would terrify us. Quickly growing systems—ones that through evolution, technology, or both, tap into previously unrecognized or untapped gradients—may spread like wildfire. But, like raging flames, they rob themselves of their own resources. Slow growers, by contrast, display an innate ingenuity; they make up in longevity and cunning what they lack in rapid gradient destruction, dissipation, and entropy production. They gratify nature not instantly but enduringly. There are many ways to skin a cat, whether Schrödinger's new cat of the role thermodynamics plays in living systems or Blake's feline of energy and fearful symmetry.

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Part III: The living

11. Thermodynamics and Life

12. Brimstone Beginnings

13. Blue Planet Blues

14. Regress under Stress

15. The Secret of Trees

16. Into the Cool

17. Trends in Evolution

© 2005 Hawkwood Institute Eric D. Schneider Into the Cool