Saturday, July 30, 2011

GAIA: A New Look at Life on Earth

James Lovelock puts forth an intriguing, fresh perspective on life on Earth as a hypothesis, which he calls "Gaia". According to the Gaia hypothesis, "the physical and chemical condition of the surface of the Earth, of the atmosphere, and of the oceans has been and is actively made fit and comfortable by the presence of life itself" which is in contrast with the orthodox point of view that "life adapted to the planetary conditions as it and they evolved their separate ways".

Lovelock's quest began when he was visiting the Jet Propulsion Laboratories of the California Institute of Technology as a scientific consultant. He attempted to think of a general characteristic of all forms of life so that the process for detection of extraterrestrial life could be made more definitive. His initial thought was to look for "entropy reduction". Later he developed the idea that a planet harboring life must have a cybernetic feedback mechanism of a planetary scale in action and some form of homeostasis would be maintaining the suitable circumstances for life even through abrupt environmental changes. In other words, the planet itself would act like a gargantuan organism.

First he argues about how life on Earth participates in maintaining (even against that punishing second law of thermodynamics) the improbable distribution of gases in the atmosphere. He says, "the atmosphere is not merely a biological product, but more probably a biological construction: not living, but like a cat's fur, a bird's feathers, or the paper of a wasp's nest, an extension of a living system designed to maintain a chosen environment." Then he goes on arguing about how the life on Earth keeps the salinity of sea water in check.

He points out that as Gaia is like a living organism, it produces wastes like we, humans do and thus pollution is not something that exclusively humans are capable of causing, a considerable amount of poisonous chemicals are released from natural sources.

Except for some repetitiousness at the end, his writing style is lucid, precise, and delightful.

Words:
  1. Biosphere: The part of the earth and its atmosphere in which living organisms exist or that is capable of supporting life
  2. Wraith: An apparition of a living person that appears as a portent just before that person's death; The ghost of a dead person; Something shadowy and insubstantial
  3. Throes: A severe pang or spasm of pain, as in childbirth
  4. Pent-up: Not given expression; repressed
  5. Surmise: To infer (something) without sufficiently conclusive evidence; To make a guess or conjecture
  6. Aeon: 1000 million years
  7. Albedo (whiteness): The proportion of sunlight reflected to space by a planet
  8. Detritus: Disintegrated or eroded matter; Accumulated material: debris
  9. status quo: The existing condition or state of affairs
  10. Equable: Unvarying; steady; Free from extremes; Not easily disturbed: serene
  11. Garner: To gather and store in or as if in a granary; To amass: acquire
  12. Turpitude: Depravity: baseness; A base act
  13. Shibboleth: A word or pronunciation that distinguishes people of one group or class from those of another; A word or phrase identified with a particular group or cause: a catchword; A commonplace saying or idea; A custom or practice that betrays one as an outsider
  14. Pittance: A meager monetary allowance, wage, or remuneration; A very small amount
  15. Immaculate: Impeccably clean: spotless; Free from stain or blemish: pure; Free from fault or error; Having no markings
  16. Conflagration: A large destructive fire
  17. Prescient: Of or relating to prescience (Knowledge of actions or events before they occur: foresight); Possessing prescience
  18. Intention tremor: With this the unfortunate sufferer who tries to pick up a pencil overreaches his target, over-compensates and swings too far the other way, oscillating back and forth in the frustrating failure to achieve a simple aim
  19. Stodgy: Dull, unimaginative, and commonplace; Prim or pompous: stuffy; Indigestible and starchy: heavy (~ food); Solidly built: stocky
  20. per se: Of, in, or by itself or oneself: intrinsically; With respect to its inherent nature ("this statement is interesting per se")
  21. Hypothermia: Abnormally low body temperature
  22. in situ: In the original or natural place or site ("carcinoma in situ")
  23. Blinkered: Subjective and limited, as in viewpoint or perception
  24. Troposphere, Stratosphere, Ionosphere, and Exosphere: Layers of the atmosphere in increasing order of height from the ground
  25. Ruminant: Any of various hoofed, even-toed, usually horned mammals of the suborder Ruminantia, such as cattle, sheep, goats, deer, and giraffes, characteristically having a stomach divided into four compartments and chewing a cud consisting of regurgitated, partially digested food
  26. Supernumeraries: One that is in excess of the regular, necessary, or usual number
  27. Vermin: Various small animals or insects, such as rats or cockroaches, that are destructive, annoying, or injurious to health
  28. Husbandry: The act or practice of cultivating crops and breeding and raising livestock: agriculture; The application of scientific principles to agriculture, especially to animal breeding; Careful management or conservation of resources: economy
  29. Perilous: Full of or involving peril (exposure to risk or harm): dangerous
  30. Pejorism: The theory that the world is deteriorating or growing worse
  31. Stoical: Seemingly indifferent to or unaffected by pleasure or pain: impassive
  32. Depredation: A predatory attack: a raid; Damage or loss: ravage
  33. Nihilistic: Of or relating to nihilism (An extreme form of skepticism that denies all existence; A doctrine holding that all values are baseless and that nothing can be known or communicated)
  34. Impunity: Exemption from punishment, penalty, or harm
Excerpts:
  • "The Second Law states unequivocally that the entropy of an open
    system must increase. Since we are all open systems, this means that
    all of us are doomed to die. Yet it is so often ignored or deliberately
    forgotten that the unending death-roll of all creatures, including
    ourselves, is the essential complement to the unceasing renewal of
    life. The death sentence of the Second Law applies only to identities,
    and could be rephrased: 'Mortality is the price of identity.' The family
    lives longer than its members, the tribe longer still, and homo sapiens
    as a species has existed for several million years. Gaia, the sum of the
    biota and those parts of the environment coming under its influence,
    is probably three and a half aeons old. This is a most remarkable yet
    quite legal avoidance of the Second Law. In the end, the sun will
    overheat and all life on Earth will cease, but that may not happen
    before another aeon has passed. Compared with the lifetime of
    our species, let alone that of an individual human being, this time
    span is no tragic brief spell, but offers almost an infinity of opportunities
    to terrestrial life."
  • "Our uncertainties about the future of our planet and the consequences
    of pollution stem largely from our ignorance of planetary
    control systems. If Gaia does indeed exist, then there are associations
    of species which co-operate to perform some essential regulatory
    functions. The thyroid gland is present in all mammals and most
    vertebrates. It harvests the meagre supplies of iodine from the internal
    bodily environment and converts them into iodine-bearing hormones
    which regulate our metabolism and without which we
    cannot live. [As indicated in chapter 6,] certain large marine algae,
    laminaria, may perform a similar function to the thyroid gland but on
    a planetary scale."
  • "The very concept of pollution is anthropocentric and it may even
    be irrelevant in the Gaian context. Many so-called pollutants are
    naturally present and it becomes exceedingly difficult to know at
    what level the appellation 'pollutant' may be justified. Carbon monoxide,
    for example, which is poisonous to us and to most large
    mammals, is a product of incomplete combustion, a toxic agent from
    exhaust gases of cars, coke or coal-burning stoves, and cigarettes; a
    pollutant put into otherwise clean fresh air by man, you might think.
    However, if the air is analysed we find that carbon monoxide gas is
    to be found everywhere. It comes from the oxidation of methane gas
    in the atmosphere itself and as much as 1,000 million tons of it are so
    produced each year. It is thus an indirect but natural vegetable
    product and is also found in the swim-bladders of many sea creatures.
    The syphonophores, for example, are loaded with this gas in concentrations
    which would speedily kill us off if present in our own atmosphere
    at similar levels."
  • "One of the most characteristic properties of all living
    organisms, from the smallest to the largest, is their capacity to develop,
    operate, and maintain systems which set a goal and then strive
    to achieve it through the cybernetic process of trial and error. The
    discovery of such a system, operating on a global scale and having as
    its goal the establishment and maintenance of optimum physical and chemical conditions for life, would surely provide us with convincing
    evidence of Gaia's existence."
  • "At the end of the last
    century Boltzman made an elegant redefinition of entropy as a
    measure of the probability of a molecular distribution. It may seem
    at first obscure, but it leads directly to what we seek. It implies that
    wherever we find a highly improbable molecular assembly it is
    probably life or one of its products, and if we find such a distribution
    to be global in extent then perhaps we are seeing something of Gaia,
    the largest living creature on Earth."
  • "If we can imagine a planet made of nothing but the component
    parts of watches, we may reasonably assume that in the fullness of
    time—perhaps 1,000 million years—gravitational forces and the restless
    motion of the wind would assemble at least one working watch.
    Life on Earth probably started in a similar manner. The countless
    number and variety of random encounters between individual molecular
    components of life may have eventually resulted in a chance
    association of parts which together could perform a life-like task,
    such as gathering sunlight and using its energy to contrive some
    further action which would otherwise have been impossible or forbidden
    by the laws of physics. (The ancient Greek myth of Prometheus
    stealing fire from heaven and the biblical story of Adam and
    Eve tasting the forbidden fruit may have far deeper roots in our
    ancestral history than we realize.) Later, as more of these primitive
    assembly-forms appeared, some successfully combined and from
    their union more complex assemblies emerged with new properties
    and powers, and united in their turn, the product of fruitful associations
    being always a more potent assembly of working parts, until
    eventually there came into being a complex entity with the properties
    of life itself: the first micro-organism and one capable of using
    sunlight and the molecules of the environment to produce its own
    duplicate.
    The odds against such a sequence of encounters leading to the first
    living entity are enormous. On the other hand, the number of random
    encounters between the component molecules of the Earth's
    primeval substance must have been incalculable. Life was thus an
    almost utterly improbable event with almost infinite opportunities of
    happening. So it did."

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