Gaia: Earth Goddess,
Scientific Theory and Catalyst for Research
By Adrienne Catone-Huber
November 19, 2002
Geography 140, Section 2
When
James Lovelock first proposed the idea in 1968 that the earth is both a living
organism and self-regulating system, he searched for a term that would capture
the essence of his new hypothesis. With
the help of novelist William Golding, he coined his
new theory Gaia, after the Greek earth goddess of that name. According to Michael Jordan's, Dictionary of Gods, "Gaia…is the
primordial essence of the earth, …Perceived as placid
and resilient..." For Lovelock's
purpose, the name was a good fit. Its
root is the basis of many commonly used scientific terms, such as Pangaea, and
it also inspires feelings of greatness and awe.
Unfortunately
for Lovelock, he didn’t realize the true weight of the term, and his theory has
been ill received from its origin. Despite
being deemed unscientific largely because of its association as a religious
term, the Gaia theory has prompted a number of studies to prove (or in some
cases disprove) parts of the hypothesis.
From that standpoint, it has proved a significant catalyst in increasing
scientific knowledge of the earth's systems and interactions.
In this
paper, I will discuss the principles behind the Gaia theory, using both
scientific knowledge and analogies between earth systems and other living
organisms and further delve into the resistance to this theory based on
religious and evolutionary biases.
Lovelock
describes the Gaia theory as one "which sees the evolution of organisms as
so closely coupled with the evolution of their physical and chemical
environment that together they constitute a single evolutionary process, which
is self-regulating." With this
definition in mind, Lovelock argues that the earth as a whole is a living
organism. His Gaia title in conjunction
with a living earth brings about visions of a sentient earth goddess. And indeed, many New Age traditions have
latched onto the concept without the scientific understanding of his
arguments.
In Gaia, The Practical
Science of Planetary Medicine, he presents a compelling case for treading
lightly on the earth. Primarily his
concern revolves around throwing earth's self-regulating processes irreparably
out of balance. He argues, for example,
that rain forests are one of earth's primary tools for temperature regulation. The rain forests use of evapotranspiration
and creation of precipitating clouds over the tropics keep that area, which
gets the most heat in the form of energy from the sun, both fertile and
cool. Additionally, numerical models
predict that once more than 65%-70% of a self-regulating ecosystem dies, that ecosystem can no longer sustain itself, and total
collapse takes place. At the current
rate of deforestation, the world's total rain forest destruction should reach
65% by 2010. Though predictions are not
guarantees, Lovelock believes there is enough evidence to practice prudence
when faced with environmental degradation.
However for many people, his environmentalism, even though based on
scientific study of earth systems, sounds like New Age reverence for his earth
goddess. As tantalizing as this
association may seem to be, this is not and never has been Lovelocks
intention.
Lynn Margulis, a close colleague of Lovelock and supporter of
the Gaia theory, sums up this association best in her book, Symbiotic Planet. "The name caught on all too well. Environmentalists and religiously inclined
people, attracted to the idea of a native goddess with power, latched onto it,
giving Gaia a distinctively nonscientific connotation. …Many scientists are
still hostile to Gaia, both the word and the idea, perhaps because it is so
resonant with anti-science and anti-intellectual folks. In popular culture, insofar as the term is
all too familiar, it refers to the notion of Mother Earth as a single
organism. Gaia, a living goddess beyond
human knowledge, will supposedly punish or reward us for our environmental
insults or blessings to her body. I
regret this personification."
With an
understanding of what Lovelock did not intend, and why his theory may have been
so reviled, let us now transition to what exactly he did intend. If Gaia is not meant as single organism or a
sentient earth goddess, than what exactly is this "living system"? This question may not be answerable without
first answering the even greater question, what exactly is life? It is no surprise to find that
Miriam-Webster's online Collegiate Dictionary, http://www.m-w.com/,
has 20 distinct entries for the word "life" as well as multiple
sub-entries within these. Perhaps the
closest scientific definition is "1 c :
an organismic state characterized by capacity for
metabolism, growth, reaction to stimuli, and reproduction." By this definition, Gaia may indeed be a
living organism.
The
earth, when its vast biota are considered as a whole
system, has continuously evolved to keep conditions suitable for life. Life, in the form of early bacteria, is
believed to have begun about 3.8 billion years ago. Conditions for the development of life had to
be near perfect at that time. However,
the planet was changing in accordance with the laws of physics and chemistry,
and conditions would not have stayed perfect.
Lovelock believes that as the planet slowly changed, the bacteria began
to "manage" the chemical and thermal processes to keep conditions
from varying beyond the capacity for life.
This is not meant as an active, intellectual management, but as an
evolutionary change in life that led those organisms capable of either adapting
to the chemical changes of the earth or initiating further changes to survive
and thrive, while those that couldn't would perish.
We all
know that evolution and adaptation is the basis for survival, however Lovelock
goes a step further to infer that some organisms evolved in such a way as to
alter the chemical and thermal reactions occurring rather than adapting to the
changing conditions. It is this ability
of life on earth to change its environment when adaptation is impossible or
undesirable, such that life itself alter the earth's atmosphere, hydrosphere
and lithosphere in order to keep the earth suitable for continued life, that is
ultimately the Gaia theory. Life on
earth does not simply evolve through adaptation, but actively regulates its
environment, such that the totality of organisms that make up life interact as
a single living entity to regulate earths physical, chemical and thermal
properties.
As a
concrete example, Lovelock looks at water.
Unlike our neighbors Venus and Mars, earth has an abundance of
water. However the early earth would
have been steadily losing its water, just as NASA has shown that Mars and
likely Venus also supported water in their early development, but eventually
dried up. He states, "Elements such
as iron reacted with water, sequestering the oxygen and releasing hydrogen
gas. The hydrogen sweeping up through
the waters and atmosphere would have caused a steady loss of water. Hydrogen gas breaks down to
hydrogen atoms at the outer limits of the atmosphere and, being too light to be
held by the Earth's gravity, escapes to space."
From
our current understanding, it is universally agreed that life would not be
possible without water. So in this case,
life would have had to coevolve with the planet, to
actively change the natural processes. Adaptation
was not an option. Surprisingly, that's
exactly what happened. Hydrogen-using
microorganisms evolved onto the scene to develop a method for hydrogen storage,
and photosynthesizing organisms began to develop, excreting oxygen, which was
believed to be only a trace gas during the Archean
period while life was coming on the scene.
Oxygen in the atmosphere would have chemically reacted with some of the
hydrogen to produce water and prevent hydrogen's escape from the atmosphere. In this way, there was planet-wide
cooperation amongst non-thinking, simple microorganisms to self-regulate the
planet in order to keep conditions favorable for continued life. Effectively, as Lovelock described in an
earlier quote, evolution of these early organisms was so closely coupled with
the evolution of their physical and chemical environment that together they constituted
a single, self-regulating, evolutionary process.
An even
more compelling argument that life is not adapting to earths chemical, physical
and thermal composition, but rather regulating them, is that of our modern day
atmosphere. Earth's atmosphere today is
made up of a mix of reactive gases, including oxidizing and reducing gases. This should not be possible. The gases should be reacting with each other
over time. Methane, for example, reacts
with oxygen in sunlight to produce carbon dioxide and water. Over time, all of the methane in the
atmosphere should have been depleted.
The only way it could remain at a steady level would be if it is
constantly pumped into the atmosphere, which it is, by earth's biota. Methane is also necessary for life, so again,
rather than attempting to adapt to an atmosphere without methane, life simply
evolved to produce it, again regulating the evolution of the environment to
keep it favorable for life. When we look
again at our neighbor planets, Mars and Venus, we find that their atmospheres
do not contain the same improbably mix of reactive gases, but rather have
atmospheres that are in an equilibrium state.
The chemical reactions have been spent, and life on those planets is no
longer possible.
Based
on these arguments, we can agree upon the first few criteria for life from
Miriam-Webster's definition above.
Looking at the totality of earth's biota as a closely coupled, symbiotic
group of coevolving organisms, we can claim that Gaia has the capacity for metabolism,
growth and reaction to stimuli. Lovelock
does a similar comparison of Gaia to a definition of life, but as that it is
his own definition, it seems fairer to see how Gaia measures up to a
"standard" definition.
We now
come to the last criteria from Miriam-Webster, the ability to reproduce. Lovelock himself has struggled with this
concept, and Lynn Margulis has published an entire
book on the definition of life. Although
the individual organisms that make up Gaia can reproduce, definition says that
Gaia itself must be able to reproduce to be considered living, which we know it
cannot. Does this mean Gaia is therefore
not actually living? Personally, I
disagree with this part of the definition.
Everyone would agree that a Mule, the offspring of a male donkey and a
female horse, is indeed alive, as are all mammals. Both sexes of mules are inherently
sterile. They can never reproduce and
left only to their own devices, the breed would die off with the death of those
animals currently alive. Yet it is
universally agreed that they are indeed living.
Despite their inability to reproduce, they have been birthed in some
fashion and for the limited extent of their time on earth, they are living
organisms. Mules can metabolize, grow
and react to stimuli. They meet the
criteria of the half dozen other scientific definitions of life found
throughout the books listed in the bibliography, with the exception of
reproduction. So perhaps it is with
Gaia. Birthed from the
universe, whether intentionally, accidentally or perhaps just improbably, one
could argue that Gaia now lives out the term of its life regardless of its
inability to reproduce. Like the
mule, left only to its own devices, Gaia will eventually die off, but that is
not a sufficient argument against its current state of being.
My
favorite analogy is that of Gaias similarity to a
redwood tree. More than 97% of a living
redwood tree is composed of an inner layer of dead wood. The tree has just a thin layer of living
cells directly under the bark. The bark
of the tree protects the living cells, keeping the tree healthy and
growing. The earth's mantle and core are
made of nonliving materials, with just the outer crust supporting life. Our atmosphere protects the living cells of
Gaia from the suns deadlier rays, and supports the movement of nutrients
throughout the system.
Of
course, in all fairness to those religious oriented traditions whom we blame
for the personification of the Gaia theory, there are some traditions, such as
Druidry, who also believe that trees have sentient spirits. For them, the difference between Gaia as an
earth goddess and Gaia as an organism closely demonstrated by a tree, may not be any difference at all.
"So
it was that, whilst walking through my local park recently, I passed a yew tree
with whom I had previously struck up an acquaintance. She's a young tree for a
yew, only about 120 years old. I saw that she'd had some vandal trouble. One of
her lower branches was cracked and twisted.… In my concern for her, I went over
to ask how she was doing….'What is your wyrd1?' I asked her. 'The wyrd of all
living things: beauty and then death.'"
From an
"Interview with a Yew Tree" by Greywolf,
founder and joint Chief of the British Druid Order.
Despite
initial resistance of the Gaia theory from the scientific community, over the
last 30 years, James Lovelock, with significant help from a number of
colleagues worldwide, has shown in clear scientific terms with specific
examples from research, modeling and analogy, that the earth, when considered
as a whole system, exhibits those characteristics commonly associated with
living organisms. His work has resulted
in two worldwide conferences on Gaia and has had an enormous influence on the
types of planetary scientific research that has been conducted since its
inception. Even if it turns out to be
incorrect, the Gaia theory has changed the way humans look at and analyze the
earth. This new, holistic approach to
understanding the impact of regional issues in the context of the potential
effect on the global environment may prove to be the key to transitioning to a
wholly sustainable human future, in harmony with the innumerable species of the
planet.
Bunyard, Peter
(editor). Gaia in Action: Science of the Living Earth, Edinburg,
Great Britain, Floris Books, 1996.
Greywolf. Interview with a Yew Tree, Worldwide Web, British Druid Order,
1998. http://www.druidorder.demon.co.uk/index1.htm
Jordan, Michael. Encyclopedia of Gods, New
York, New York, Facts on File, 1993.
Lovelock, James. GAIA: The Practical Science of Planetary
Medicine, London, Great Britain, Oxford University Press, 2000.
Margulis, Lynn.
Symbiotic
Planet {A New Look at Evolution}, Amherst, Massachusetts, Basic Books, 1998.
Margulis,
Lynn; Sagan, Dorian; Eldredge,
Niles. What is Life?, Berkley, California, University
of California Press, 2000.