Teh wrote:
(Nested quote removed.)
As you say, Gaia is a metaphor, just not a particularly suitable one to apply to reality.
Okay folk, Gaia is useful as metaphor in the way described above, but it is more than this...it is an intuitive representation, from a scientist, which has further led to significant evidence to support hypotheses based on 'Gaia'. I might add that 'The Big Bang' and other key theories in science are useful predictors and orientation points, often intuitively arrived at (ALL scientists use intuition, whether they realise it or not -they are human), but these theories (including 'The Big Bang') cannot be irrefutably proved, nor the science behind them completely explained. Working hypotheses are useful and this is precisely what Gaia is -a working hypothesis. Nevertheless as far as I understand it it provides a useful framework which has led to significant information gathering- -below I have copied and pasted information from Wikipedia. I understand this is not the most credible source, but it is true enough, and I haven't currently got time to search for the more credible sources online -but they are there if you want to look for them, I assure you:
The Gaia hypothesis, also known as Gaia theory or Gaia principle, proposes that organisms interact with their inorganic surroundings on Earth to form a self-regulating, complex system that contributes to maintaining the conditions for life on the planet. Topics of interest include how the biosphere and the evolution of life forms affect the stability of global temperature, ocean salinity, oxygen in the atmosphere and other environmental variables that affect the habitability of Earth.
The hypothesis was formulated by the scientist James Lovelock[1] and co-developed by the microbiologist Lynn Margulis in the 1970s.[2] While early versions of the hypothesis were criticized for being teleological and contradicting principles of natural selection, later refinements have resulted in ideas highlighted by the Gaia Hypothesis being used in disciplines such as geophysiology, Earth system science, biogeochemistry, systems ecology, and climate science.[3][4][5] In 2006, the Geological Society of London awarded Lovelock the Wollaston Medal largely for his work on the Gaia theory.[6]
Gaian hypotheses suggest that organisms co-evolve with their environment: that is, they "influence their abiotic environment, and that environment in turn influences the biota by Darwinian process". Lovelock (1995) gave evidence of this in his second book, showing the evolution from the world of the early thermo-acido-philic and methanogenic bacteria towards the oxygen-enriched atmosphere today that supports more complex life.
The scientifically accepted form of the hypothesis has been called "influential Gaia". It states the biota influence certain aspects of the abiotic world, e.g. temperature and atmosphere. They state the evolution of life and its environment may affect each other. An example is how the activity of photosynthetic bacteria during Precambrian times have completely modified the Earth atmosphere to turn it aerobic, and as such supporting evolution of life (in particular eukaryotic life).
Biologists and Earth scientists usually view the factors that stabilize the characteristics of a period as an undirected emergent property or entelechy of the system; as each individual species pursues its own self-interest, for example, their combined actions may have counterbalancing effects on environmental change. Opponents of this view sometimes reference examples of events that resulted in dramatic change rather than stable equilibrium, such as the conversion of the Earth's atmosphere from a reducing environment to an oxygen-rich one.
Fringe science versions of the hypothesis claim that changes in the biosphere are brought about through the coordination of living organisms and maintain those conditions through homeostasis. In Gaia philosophy, all lifeforms are considered part of one single living planetary being called Gaia. In this view, the atmosphere, the seas and the terrestrial crust would be results of interventions carried out by Gaia through the coevolving diversity of living organisms. However, the Earth as a unit does not match the generally accepted biological criteria for life itself, for example, there is no evidence to suggest that "Gaia" has reproduced. This argument is countered by the fact that mules do not reproduce, yet they are also classified as living.
- By Bethel Saint Bright
- By Sy Borg