“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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