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~~ GAIA ~~

The Earth

Supported by a number of celebrities, Gaia is often thought of as either a “new religion” or a revamped version of an ancient one. In reality, Gaia is neither old nor a religion. In fact it sprang from an idea a NASA scientist had about a way of detecting life on Mars. Later it was found to have implications not only for finding life on Mars, and therefore on other planets, but also for understanding the way that our planet and the life on it formed and subsequently evolved. Ultimately it led scientists to a way of thinking about our planet so radical that it could seriously be called a scientific revolution.

James Lovelock was involved in NASA’s missions to Mars in the 1960s. He worked closely with Lynn Margolis who became the other main protagonist for Gaia. The Gaia hypothesis was first formulated in the 1960s when in the words of Jon Turney “... it met with widespread indifference. It was simply too far out of line with the way that most earth scientists were thinking about their subject to be heard clearly". It was later popularised in a book in the 1970s and the response was varied and often not welcoming. The name "Gaia" is taken from the name of the Greek goddess of the Earth.

Lovelock argued that the plans they had at that time for detecting life on the Martian surface were too specific. They depended on detecting particular chemicals required for life on Earth. However, there was no real reason to expect that life on Mars, if it existed, was anything like life on Earth or that it used the same chemicals. A much more general way of detecting life was needed. The most general way he could think of was to look for signs of entropy-reduction.

Entropy is a measure of disorganisation or randomness; the less organised anything is the more entropy it has. Under normal circumstances, entropy always increases. For instance, the pyramids were a highly organised structure when they were built but over time, bits fell off, they were raided for building materials and the ravages of wind and weather took their toll, so that eventually they will become a disorganised heap of rubble. Eventually even the rubble will return into the sand and be lost. Organisation has given way to disorganisation.

The interesting thing about life is that it temporarily reverses entropy. Life takes disorganised basic materials and organises them into – well, an organism.

On a planet with no life you would expect everything to gradually descend into a disorganised state. Highly reactive elements and compounds would combine to form inert substances so that eventually there would be no reactive substances left. However, on Earth, for instance, there are plenty of reactive substances. In particular, the atmosphere contains a lot of Oxygen which is highly reactive. Something is stopping these reactive substances from combining into inert compounds and that something is life.

Lovelock reasoned that if you could find a lot of highly reactive elements and compounds on a particular planet, this would probably be a giveaway that life was present on the planet. To begin with, Gaia was no more than a neat way of finding life.

If you strike a match or start a fire you are taking advantage of the fact that the Earth doesn’t just have a lot of free Oxygen, but that it is in just the right proportion for the Oxygen to give rise to a flame. The chemicals in the head of the match ignite through friction but the stick goes on burning, just one indication that much of the stuff of our world is just a few degrees on the right side of burning.

Lovelock realised that the balance of atmospheric gases was so favourable to life that it was most unlikely that these conditions resulted from mere chance. If the balance was slightly different, the oxygen in the atmosphere would be useless for the development of life. Maybe the atmosphere has the right proportions of gases to engender both burning and life, because that is how life wants it to be and life had some way of controlling the make up of the atmosphere.

This might seem to be a small statement but over the last forty years it has led to a revolution in science. Previously there were the “Earth sciences”, including geology, chemistry and physics, which explained how the Earth was formed and subsequently evolved. Then, millions of years after the formation of the Earth came plants and animals, the realm of the “life sciences” including biology. However, the Earth sciences and the life sciences were considered to be completely separate. When life arrived it simply did as well as it could in the physical conditions which existed, dodging volcanoes, tsunamis and the occasional asteroid collision. Gaia changed all that; suddenly the Earth sciences and the life sciences were interactive; the Earth sciences set the stage for life to get going but life also influenced the way the physics and chemistry of our planet developed.

Not surprisingly, Gaia was initially met by the scientific community often with reactions ranging from coldness to open hostility. Gaia was denounced as unprovable and unnecessary conjecture, as “green politics” disguised as science, even as mumbo-jumbo. It took the best part of thirty years for its tenets to be accepted into mainstream science.

Subsequently, Gaia has been taken up and has become a basis for theories ranging from the reasonable to the ridiculous. However, one area in particular deserves exploring. This is the idea that the entire planet functions as an organism in its own right.

The Ebola virus is a particularly destructive organism which has been said to effectively dissolve its victims until they become virtually a Petri dish of nutrients for the virus. Yet the Ebola virus was largely contained within the rain forest until we started cutting the rain forest down; then it came out of the forest and started fighting back on behalf of the planet. This is not unlike the way that our white blood cells rally to fight disease; we fight viruses, whereas from the planet’s point of view the invader, the infection, is ourselves.

The obvious objection to this is that the biosphere does not appear to be working as a harmonious unit; the species compete with each other and spend a lot of time eating each other. How could such a situation lead to the planet acting as a single organism?

Life started with single-celled organisms. The next stage is represented by the sponges, which are effectively colonies of single celled animals. An interesting fact is that if you put several live sponges into a blender so that they are broken down into individual cells and then leave them for a while, eventually the sponges will reform and each of the cells knows which sponge it belongs to.

Later came full multi-cellular animals including us. In reality each one of us is a colony of about six billion single-celled animals, but that doesn’t stop the colony from having a sense of self, a feeling of “me”. Is it so unreasonable to expect this kind of organisation to extend to a higher level?

Eugene Marais didn’t think it was unreasonable at all. In his book “The Soul of the White Ant”, he explains his observation that a termite colony appears to act with a single purpose. Each of the individual insects appears to be controlled by the queen, even when they are away from the nest. Back in the 1960s it was not at all obvious how this happened and at first he thought that there might be some kind of extra-sensory perception at work. It was some years before scientists discovered that the queen was using pheromones – airborne hormones – to control the other ants. So here we have the first indication of a super-organism consisting of a large number of individual animals with centralised control.

A further development came from theoretical work by the astronomer Fred Hoyle, and Chandra Wickramsinghe.

Recently there has been a rise in religious fundamentalism resulting in a revival of the argument between those who support Darwinian theory and Creationism. The work of Hoyle and Wickramsinghe is so different from conventional Darwinian theory that it almost represents a third alternative.

Darwinists have argued that once a species comes into existence it evolves “on its own” in direct competition with other species. There are exceptions which prove the rule, known as “symbiosis”, where species work in harmony for their mutual benefit. E. Coli, for instance, is treated as an invasive organism when it arrives externally but it is necessary in the gut. However, generally species are regarded as separate and competitive.

There are, however, some curious anomalies in the genetic code. Usually only about 25 per cent of the code is actually used as the blueprint; the rest appears to be largely garbage. Some of it seems to have crossed species. The DNA of a cat, for instance, contains the coding for the tail fins of a trout. Hoyle and Wickramsinghe reasoned that the species are not, in fact, separate and discreet for all time but rather are islands in a sea of genetic information represented by the viruses, which carry information from one species to another.

On the basis of all of this, it is not beyond reasonable bounds to expect that there is some overall level of organisation of the biosphere, and that the biosphere itself functions in at least some respects as a single organism. In a nutshell, the Earth is alive.

In the words of Fritjof Capra, best known for his book, ‘The Tao of Physics’:

The Earth, then, is a living system; it functions not just like an organism
but actually seems to be an organism – Gaia, a living planetary being.
Her properties and activities cannot be predicted from the sum of her parts;
every one of her tissues is linked to every other tissue and all of them
are mutually interdependent.

Acknowledgements and further reading:

Lovelock & GaiaJon Turney RodgerIcon Books UK
Soul of the White AntEugene Marais
The BiosphereVernadskyCopernicus Books
Scientists on Gaia IIJ. Miller & P. Boston (Ed.)MIT Press
Gaia - The Growth of an IdeaLawrence JosephSt. Martins Press

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© Ken James 2008