Gaia theory science: Encyclopedia II - Gaia theory science - Recent Developments

Gaia theory science - Recent Developments

Gaia theory science - The Second Gaia Conference

By the time of the 2nd Chapman Conference on the Gaia Hypothesis, held at Valencia, in Spain on the 23 June 2000, the situation had developed significantly in accordance with the developing science of Bio-geophysiology. Rather than a discussion of the Gaian teleological views, or "types" of Gaia Theory, the focus was upon the specific mechanisms by which basic short term homeostasis was maintained within a framework of significant evolutionary long term structural change.

The major questions were:--

A. "How has the global biogeochemical/climate system called Gaia changed in time? What is its history? Can Gaia maintain stability of the system at one time scale but still undergo vectorial change at longer time scales? How can the geologic record be used to examine these questions?

B. What is the structure of Gaia? Are the feedbacks sufficiently strong to influence the evolution of climate? Are there parts of the system determined pragmatically by whatever disciplinary study is being undertaken at any given time or are there a set of parts that should be taken as most true for understanding Gaia as containing evolving organisms over time? What are the feedbacks among these different parts of the Gaian system, and what does the near closure of matter mean for the structure of Gaia as a global ecosystem and for the productivity of life?

C. How do models of Gaian processes and phenomena relate to reality and how do they help address and understand Gaia? How do results from Daisyworld transfer to the real world? What are the main candidates for "daisies"? Does it matter for Gaia theory whether we find daisies or not? How should we be searching for daisies, and should we intensify the search? How can Gaian mechanisms be investigated using process models or global models of the climate system which include the biota and allow for chemical cycling?"

Tyler Volk has suggested that once life evolves, a Gaian system is almost ievitably produced as a result of an evolution towards far from equilibrium homeostatic states that maximise entropy production (MEP). [Kleidon] in Climate Change 66(3) Beyond Gaia: Thermodynamics of Life and Earth System Functioning, has confirmed Volk's hypothesis "that homeostatic behavior can emerge from a state of MEP associated with the planetary albedo." and "that the resulting behavior of a biotic Earth at a state of MEP may well lead to near-homeostatic behavior of the Earth system on long time scales, as stated by the Gaia hypothesis."

[Staley] has recently demonstrated in the Journal of Theoretical Biology 218(1) Sept 7, 2002 that Darwinian selection leads to Gaia. In "an alternative form of Gaia theory based on more traditional Darwinian principles is proposed. In the new approach, environmental regulation is a consequence of population dynamics, not Darwinian selection. The role of selection is to favor organisms that are best adapted to prevailing environmental conditions. However, the environment is not a static backdrop for evolution, but is heavily influenced by the presence of living organisms. The resulting co-evolving dynamical process eventually leads to the convergence of equilibrium and optimal conditions."

Adapted from the Wikipedia article "Recent Developments", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki