Metabolic Metaphysics: Organism and Environment

The Star Larvae Hypothesis
Nature's Plan for Humankind
Part 1. Metabolic Metaphysics

Organism and Environment

Some cross sections of nature’s metabolism act like discrete unities. These organisms elude easy delineation, however, because their metabolisms diffuse into their environments.

Think you're Bright? Rise and Shine at http://starlarvae.blogspot.com/

The interlocking of natural systems in a hierarchy of ascending scale is a common model of nature's organization. The model typically starts with subatomic particles, then climbs to the level of atoms and molecules, then on to cells and organisms, ecosystems and biospheres and from there to the levels of the cosmic beyond—with as many intermediate steps as necessary for the occasion. The problem with this model is that the levels are defined by convention; they are not naturally discrete. Any given level in the hierarchy is an environment for lower levels, and it exchanges matter and/or energy with them. And any given level acts as an organism or population of organisms embedded in a higher-level environment. An organism exchanges matter and energy with its environment, and as a result the precise definition, or delineation, of the organism is problematic. This situation is familiar enough in the case of the many biological cycles that run through an ecosystem, all of which ultimately depend on electromagnetic radiation from an extraterrestrial source—the sun.

But even when events occur below the biological scale, as when atoms bond to form molecules, the identity of each participant becomes fuzzy. A molecule is an environment in which the atoms' electrons are shared or exchanged, and the relationship that results is the chemical bond that keeps the atoms in place. The environment of the molecule reconstitutes the precise components that make up the atom. To which atom do the shared electrons belong?

To illustrate the applicability of this principle at the other end of the hierarchy, on a scale larger than the biological, consider the Earth. Taken as a unity, or single organism, the Earth was dubbed Gaia by scientist James Lovelock. Gaia was an ancient Earth goddess, and Lovelock adopted the name to convey the unity of life on Earth as constituting a single self-regulating entity, with life itself actively maintaining the terrestrial environment in a condition that supports life. Lovelock's model of the biosphere actively maintaining itself—the entire organic world acting in concert on its own behalf—is gaining ground as the overarching model of ecological science.

"No science can be more secure than the unconscious metaphysics which tacitly it presupposes. The individual thing is necessarily a modification of its environment, and cannot be understood in disjunction. All reasoning, apart from some metaphysical reference, is vicious."

-- Alfred North Whitehead
Adventures of Ideas

But, as with any organism, the living Earth is not a discrete, self-contained system. It is embedded in an environment. That environment is the solar system, populated by the sun, other planets, moons, asteroids, and clouds of comets. The sun plays an obvious, essential role in keeping the whole show running. But the other bodies of the solar system also seem to be essential for life to evolve. In "Rare Earth," Peter D. Ward and Donald Brownlee catalog many of the cosmic coincidences that make Earth hospitable to the evolution of complex biological life. Their observations include the following:

Not only is Earth the right distance from a star of the right size to make bio-friendly conditions possible, but its conspicuously large moon is situated precisely so as to stabilize the planet’s season-generating tilt.
The outer giants, Jupiter and Saturn, act as gravitational vacuum cleaners, protecting the inner planets, including Earth, from excessive bombardment by stray comets and asteroids. Some of these projectiles get through, but Ward and Brownlee calculate that without the gravitational clean-up work performed by Jupiter and Saturn, Gaia long ago would have been pummeled beyond recovery.
Much of Earth's water supply is likely to have been delivered by comets. It is hardly controversial anymore to suggest that comets probably also delivered a supply of organic materials to the early Earth, in effect kick-starting the genesis of biological life.

This inventory of dependencies suggests that Gaia is a misnomer. The planet Earth is one component of a larger system, which as a whole can be thought of as constituting a discrete organism. But even that organism, our solar system, is able to thrive only because it resides in a hospitable neighborhood. Neither much nearer the center of the Milky Way galaxy nor much nearer the fringes would it find adequately hospitable conditions. The solar system resides in what cosmologists call a galactic habitable zone, wherein the density of matter and the kinds of materials needed to assemble solar systems are available. (See "Refuges of Life in a Hostile Universe," by Guillermo Gonzalez, Donald Brownlee, and Peter D Ward, Scientific American, October 2001.)

"Abstract speculation has been the salvation of the world—speculations which made systems and then transcended them, speculations which ventured to the furthest limits of abstraction. To set limits to speculation is treason to the future."

-- Alfred North Whitehead
The Function of Reason

Based on our solar system’s particulars, Ward and Brownlee dismiss the prospect of complex life existing elsewhere in the universe. They argue that the precise arrangement of conditions needed is too unlikely to occur again. But nature’s propensity to self-organize begs the question as to what constitutes an unlikely coincidence and what constitutes a predictable result of nature's self-organizing tendencies.

Ward and Brownlee interpret their data in secular terms. But others interpret the same data in religious terms. The result is the notion that Earth is a Privileged Planet, one so uniquely designed to be hospitable to biological life that only a supernatural explanation is plausible. Now that telescopes are revealing planets around other stars, the Rare Earth hypothesis is becoming testable. The scientific and religious communities might not have to wait long to see whether their hypotheses survive telescopic scrutiny.

Identifying any level in nature's hierarchy as discrete is an exercise in imprecision. The individual organism might seem to be an unambiguously delineated unit of nature, but, as the Gaia example, or any study of biological food chains, reveals, the organism exists only in a state of dependence on its environment. Perversely, environments confuse the issue not only by highlighting the ambiguous boundaries among nature's levels of scale, but also by introducing organisms to one another and fostering mutually beneficial, sometimes essential, relationships among them. The result, symbiosis, further challenges any easy delineation of the discrete organism.