Gaia and Daisyworld

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Gaia and Daisyworld
Can we treat the earth as a regulating organism?

• Jamie Wood
• ajw511_at_york.ac.uk

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A statement

• ...a complex entity involving the Earth's
  biosphere, atmosphere, oceans, and soil the
  totality constituting a feedback of cybernetic
  systems which seeks an optimal physical and
  chemical environment for life on this planet.'
• Dr James Lovelock Gaia - A New Look at Life on
  Earth

Where did that come from!
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Lets take a step back
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Solar system experiments
...change the chemical composition of the
atmosphere to render it recognisably different
from the atmosphere of a lifeless planet. Ages
of Gaia

• Venus N (lt2). CO2 (95). No oxygen. Atmosphere
  in chemical equilibrium

Mars N (lt3) CO2 (95) No oxygen. Atmosphere
in chemical equilibrium
Earth N (77), CO2( 0.03) 21 oxygen.
Atmosphere not in chemical equilibrium
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What is proposed?

• That the Earth is a living system.. an organism.

i.e. The biota (the biological components)
maintain the abiotic variables at levels close
to, or at, those which are optimal for life
Homoeostasis (Homeostasis).
...Homeostasis is maintained by active feedback
processes operated automatically and
unconsciously by the biota. Ages of Gaia From
Lovelock and Margulis 1974
symbiosis seen from space
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Phytoplankton and Redfield Ratios
Phytoplankton in the deep ocean

• Redfield Ratio is the ratio of carbon, nitrogen
  and phosphorous in the plankton, 106161,
  derived from stoichiometry.

It is also the ratio in the ocean, perfect for
growth?
But which comes first? Are the plankton adapted
to their environment? Or are they influencing it?
Predicted sulphur flux from the ocean through
dimethyl suphite
Linked to albedo regulation through cloud
formation?
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Earth as an organism?
Not a new idea.
Conjectured by James Hutton in the 18th Century
and T H Huxley in the 19th Cent.

• Large Russian School recently revisited by
  Lapenis (2002)
• Kropotkin, Rizpolozhensky, Vernadsky, Kostitzin

Alfred Lotke ...that the physical laws
governing evolution in all probability take on a
simpler form when referred to the system (of
organisms plus environment) as a whole than to
any portion thereof
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Critique

• Wade Doolittle
• ...is based on a view of natural selection...
  ...which is unquestionably false.
• Co-Evolution Quarterly 1980

Richard Dawkins ...there was no way for
evolution by natural selection to lead to
altruism on a Global scale" The Extended
Phenotype
Stephen Schneider The Geological record seems
much more in accord with the view that the
organisms that are better able to compete have
come to dominate...
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Reformation...
James Kirchner argued that there are several Gaia
hypotheses
Influential Gaia. The biota has a substantial
inuence over the aspects of the composition of
the abiotic world.
Coevolutionary Gaia. The biota inuences the
environment and the environment influences the
evolution of the biota.
Homeostatic Gaia. The biota inuences the abiotic
world in a way that is stabilising the major
linkages between the biota and the abiotic world
are negative feedback loops.
Teleological Gaia. The atmosphere is kept in
homeostasis not just by the biota, but for the
biota some sense of purpose is implied.

• Optimizing Gaia. The biota manipulates the
  environment to create favourable or optimal
  conditions for itself.

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Gaia today

• ...some otherwise sensible scientists jumped
  off. This is probably still the case. But as a
  theory, Gaia is now winning.
• ...established - if it were necessary - that
  Gaia had at last moved from the fringe to the
  centre of Earth science.
• Crispin Tickell, www.crispintickell.com
• Lecture given in Jan 2007

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Revenge of Gaia?

• Lovelock has become a spokesperson for Green
  Movement.

Analogy of mankind being a self-replicating viral
infection of Gaia.
Does Gaia have an immune system...
...we may be about to find out.
Lovelock makes the case that we are pushing Gaia
too hard, with unpleasant consequences.
Huge policy implications if we accept Gaia as
true.
But how do we prove or establish Gaia theory?
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Daisyworld

• A mathematical basis for Gaia?

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What is Daisyworld?
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Daisyworld History Adaptation

• Model introduced by Watson and Lovelock (1984).
• Chaos predicted by Zeng et. al.
• Exact Solution by Saunders (1995)
• idea of daisies altering their optimal
  temperature
• Model by Robinson and Robertson (1998)
• adaptation of optimal temperature leads to
  lack of regulation
• Reply by Lenton and Lovelock (2000)
• physical bounds on optimal temperature restores
  homeostasis
• Other recent work by Staley (2002), Sugimoto
  (2002) and Pujol (2005) .

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Daisyworld History Spatial models

• Von Bloh et.al. (1997) presents a spatial
  daisyworld model
• The temperature equilibrium relaxed replaced
  by full diffusion equation.
• Daisies modeled as cellular automata
• Ackland et.al. (2002) looks a latitude dependent
  effects
• Desert formation
• Ackland (2004) examines the link with Max Ent
• Max Life, not Max Ent principle
• Other recent work by Adams et.al. (2004) and
  Ballodocci et.al. (2005)
• Pattern formation and vegetation scaling

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Daisyworld a model for Gaia
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Temperature Response
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Occupation of Ground
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Acknowledgements

• All the images here are from Wikipedia