by Sean Chamberlin
from
OceanOnLine.com Website
Spider web at
Montana de Oro; photo by Sean Chamberlin |
Is Gaia Here?
The startling
and pervasive expansion of life on Earth begs several
questions concerning the nature of evolution and the
processes which feed it. In a strict Darwinian sense, new
life arose as competitive pressures made other life
unsuccessful. Species at a disadvantage came to an end. On
the other end of the spectrum, the cooperation between cells
at a very early stage -- the process of symbiogenesis
-- casts a different view of the development of life on the
planet.
Whether life
arose and took command of planetary processes for its own
good, as proposed by Lovelock in his Gaia theory;
whether life arose as the sum of populations of individual
genomes with an expressed fitness or ability to survive
under a given set of environmental conditions, as popularly
expressed by evolutionists and molecular biologists; or
whether some laws of non-equilibrium |
thermodynamics pulsate
at the quantum level of life such that symbiotic organisms,
communities of organisms, and entire ecosystems had to arise to
satisfy these pulses, as suggested by some physicists and myself,
are questions that will continue to drive our science.
The importance of
looking backwards into the fossil record, and indeed, into space,
cannot be overstated. The evolution of life and biogeochemical
processes on this planet will be most easily understood by gaining
some sense of what has happened in the past, be it on our planet or
in the far reaches of interstellar space.
In this quest, we must also look ahead. We must gauge the effects of
our own mechanization and evolution on the globe. We must scrutinize
the smallest impacts and synthesize their individual fluxes into a
global model that gives us the best picture of what might happen to
our planet. We have to give it our best shot. As evidenced by the
rapid demise of many marine organisms 245 million years ago and the
dinosaurs 65 million years ago, the Universe waits for no one.
What does this have to do with Gaia? Only that it is
prudent to keep our minds open to all possibilities. Life's
extraordinary "gift" of oxygen 2 billion years ago, and its
maintenance of that "gift" for another 2 billion, exemplify
the power that life -- microbial life -- holds over the planet. We
would be wise not to dismiss the possibility that microorganisms
hold the purse strings of other equally powerful planetary
processes. If the foundations of Gaia lie in the
microbial world, and a good case could be made for this premise,
then man's reign here is not because of his own advanced
evolutionary state; rather, man is here by permission.
Considering that every cell in our body contains a
mitochondrion, which originated as a bacterial cell, and
considering that our own bodies contain as many as ten thousand
billion bacterial cells -- nearly ten percent of our body weight
-- we might be wise to reflect on who is ruling whom!
Be that as it may, we will discuss at a later date the possible
mechanisms and evidence for them that would support the idea of an
interconnected, Gaian planet. In the meantime, I will
leave you with these few paragraphs from Margulis and
Sagan, which sums up much of which we have just learned.
It is an
illuminating peculiarity of the microcosm that explosive
geological events in the past have never led to the total
destruction of the biosphere. Indeed, like an artist whose
misery catalyzes beautiful works of art, extensive catastrophe
seems to have immediately preceded major evolutionary
innovations.
Life on Earth answers threats, injuries, and
losses with innovations, growth, and reproduction. The
disastrous loss of needed hydrogen from the gravitational field
of the earth led to one of the greatest evolutionary innovations
of all time: the use of water (H2O) in
photosynthesis. But it has also led to a tremendous pollution
crisis, the accumulation of oxygen gas, which was originally
toxic to the vast majority of organisms living on the planet.
Nonetheless, the oxygen crisis 1,000 million years ago promoted
the evolution of respiring bacteria which used oxygen to derive
biochemical energy more efficiently than ever before. These
bacteria were symbiotic and merged with other bacteria to form
eukaryotic cells -- which, becoming
multicellular, evolved into fungi, plants, and animals.
The most severe mass extinctions the world has ever known, at
the Permo-Triassic boundary 245 million years ago, were
rapidly followed by the rise of mammals, with their sharp eyes
and large receptive brains. The Cretaceous catastrophe,
including the disappearance of dinosaurs 66 million years ago,
cleared the way for the development of the first primates, whose
intricate eye-hand coordination led to technology. World War II
ushered in radar, nuclear weapons, and the electronic age. And
the holocaust of Hiroshima and Nagasaki over forty years ago
decimated Japanese industry and culture, unwittingly clearing
the way for a new beginning in the form of a rising red sun of
the Japanese information empire.
With each crisis the biosphere seems to take one
step backwards and two steps forward -- the two steps forward
being an evolutionary solution that surmounts the
boundaries of the original problem. Not only meeting but going
beyond challenges confirms that the biosphere is extremely
resilient, that it recovers from tremors with renewed vigor.
Nuclear conflagration in the northern hemisphere would kill
hundreds of millions of human beings. But it would not be the
end of life on Earth, and, as heartless as it
sounds, a human Armageddon might prepare the biosphere for less
self-centered forms of life. As different from us as we are from
dinosaurs, such future beings may have evolved through matter,
life, and consciousness to a new superordinate stage of
organization, and in doing so, consider human beings as
impressive as we do iguanas.
While boldly stated and
even startling, these paragraphs in their book at least help us to
step back from our human-centric view of life, and help us to
consider the enormity of life forces of which we are a part. Much as
ancient men had to reconcile the fact that the Earth
was not the center of the Universe, so too might modern man have to
realize that he is not the dominant player in the circle of Life on
this planet.
Question: If
Gaia did begin to operate during the evolution of the
Earth, when might it have started?
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