It is indisputable that nothing in biology makes sense except in the light of evolution, but...

...nothing in evolution makes sense except in the light of Plate Tectonics.

19 February, 2010

Gaia and the Na'vi

I suppose it had to work its way around to this. I've been putting it off, but my last post (Time and Place) leaves me no option but to follow up with this discussion about Gaia. I know many of you are sick of Avatar, but I found the film useful as a foundation for this essay.

This is NOT a review of the film, and my intent is not to either praise or bash it. Having said that, let's clear the air about my opinion so I can then get on to why I am using it to discuss Gaia and to expand on the Anthropic Principle (Time and Place). I admit I was charmed by the visuals of the film and I was impressed by the imagination that went into the biota. The concept of operating in an inhospitable environment via a telepathic avatar was a cool and original new take on space fantasies. Overall, I suppose the film was all right if you don't mind a story line cobbled together from Pocahontas and Fern Gully.

I was turned off, however, just a couple minutes into the film when they said that the rare mineral for which they were raping this planet was called ... wait for it..... "Unobtainium!"

WHAT?!?!?!?! Unobtainium? It's like the old Rocky and Bullwinkle episodes in which the anti-gravity mineral they were all trying to find was called upsidaisium; or the one in which the ingredient in the new super secret bomb was called Hush-a-boom. At least that was a cartoon, made with tongue firmly embedded in cheek. But a $50 Million film and they called it unobtainium??

Apart from that, there were two particular things which I did not like: one that disappointed me (today's topic) and one that ticked me off. So what ticked me off? Once again, it's the BAD old corporate MINING company that will do anything, kill anyone, destroy everything, with reckless abandon to get every last gram of whatever it is (see my post called "Resourceful" below). I know mining concerns didn't have a good environmental track record in the past, but name me one industry that DID have a good record 50 years ago. Mining companies are probably amongst the better environmental stewards now - I know, I work in mining stormwater management, waste management and mine reclamation. Just the grumblings of a mining geologist, so you can move on to the real point.

The thing that disappointed me. It began as something I was excited about as the story unfolded. There is a pervasive undercurrent of the "The Gaia Hypothesis" throughout the film and it seemed as though, for once, the film makers had understood this concept and I was prepared to love this film (once the "unobtainium" incident had faded into the background of the visual spectacle). What I thought at first was going to be a proper treatment of this idea went south and by the end of the film I was pissed.

Never heard of the Gaia Hypothesis? It is a product of the late '60s/early '70s (Do I have to say more than that?). The Gaia Hypothesis can be summed up that all Earth systems (Lithosphere, hydrosphere, atmosphere, biosphere - not blogosphere but I am working on that one) are all constituent parts of a single symbiotic system; i.e., the Earth itself and all its life forms constitute an organic whole - the entire planet is a single, multifaceted organism - the whole place is literally alive and interdependent.

By way of background, Gaia was one of the 'original' Greek gods (a goddess actually). She was the Earth mother, who spawned Uranus and Oceanus, from whom all the Titans and then the regular gods, sprang. Gaia was the everlasting Earth from which all other things,including the other gods, and ultimately, all life energy flowed. BTW, the name Gaia, in its more European form "Gaea" and its more recent anglicized form "Gea" is the root of our words for things related to the Earth, like Geography - the graphing (mapping) of the Earth, Geology - the study of the Earth, Pangea (Pangaea) in a Plate Tectonic setting. OK. Back to the Gaia Hypothesis.

There are a couple versions of the Gaia Hypothesis:

  • a weak version in which people recognize that all life is not only connected but that life is also dependent on the physical conditions of the various ecosystems, and the ecosystems are maintained and changed by the presence and actions of life;
  • a strong version, in which the non-biological spheres of the Earth are an active part of the living whole - literally, constituents of the total organismic whole; the rock, water and air parts equally integral with biota in the 'life force'.

There is some modicum of truth in the weak version of the Gaia Hypothesis evident in even a cursory inspection of Earth history and the changes over time (see Time and Place, below as well as Status Quo). The strong version is simply teleological... it's a religion. It's another manifestation of the Anthropic Principle (see, once again, Time and Place, below - I told you this post was necessary after I had written Time and Place).

So in what way is the Gaia Hypothesis something we should entertain seriously?

The Earth we know, all of its mountains, valleys, forests, deserts, rivers, the beautiful erosional landscapes of glacier-sculpted peaks, aretes, horns, cirques, fjords, are all the result of weathering, which, in turn is the result of climate, which in turn is the result of the very specific nature and composition of our atmosphere. The atmosphere was literally created by living organisms (marine plants actually) and is now maintained by life. Differences in atmospheric composition over time and place result in differences in wind and water distribution which results in different landscapes. Changes in continental positions also change climates, locally and globally; the natural changes in climate have the most profound effects on biota, which evolve and/or become extinct as their ecosystems change (this is another, future topic).

But there is feedback the other way. The presence of forests modify local climates to keep areas moist, affecting downwind climates and contributing enormously to the hydrologic cycle of the entire planet (click on the image for a blow-up view). Burrowing organisms literally MAKE soil, which is a huge sink for CO2 regulation in the atmosphere, helping regulate near-surface temperatures. The soil also controls the infiltration and runoff of rainwater and groundwater, as well as stream flows, which controls sedimentation and distribution of sedimentary rocks... And the type of soil is dependent on the type of underlying rock and the climate, which latter controls which organisms are present to work on the rock...

I haven't even scratched the surface, but I hope you see that the local climate, which is mostly a function of latitude and position of the continents, controls what life forms are present at any location, and the life forms modify the environment in numerous ways and change the abiotic components, which have a further effect on what OTHER biota can be supported and the whole contributes in significant ways to regional and global ambient conditions, including feedback on the climate. At the root, however, life on Earth has evolved into ever-changing environments which result from the interaction of the biosphere with the elements of the lithosphere, hydrosphere and atmosphere - life creates the conditions for its own future evolution and survival. It isn't conscious. If something gets out of balance, extinctions ensue. Period. Gaia (nature) simply doesn't care. It is dispassionate. (Once agin, see Time and Place).

Now this interdependence is energy driven. And the energy comes from two sources: the Sun, the main driver of all life and most of our industrial society; inner heat from the Earth's interior. Both are necessary if one wants to consider the Gaia Hypothesis even remotely real. We are not certain how much a role Earth's inherent heat played in kick-starting life in the first place - likely it was THE energy source, but that is mere speculation on my part based on the fact that the Sun was less active and less strong in the early solar system and on the fact that the heat flux from the Earth's interior was far greater than currently. The current heat flux from the Earth is miniscule and has an impact on life only in areas such as mid-ocean ridges where thriving ecosystems are present at deep sea volcanic ridge vents and the like.

The Earth's internal heat plays a more subtle role. It is the driving force behind the elevation of land and the recycling of Earth materials which have collectively resulted in the presence of continents and ocean basins. More to the point the elevation and subsidence of land plays a huge role in the interaction of land and biota in ecosystems, and in the generation of soil, the life-sustaining substrate of all life, which is produced by life in combination with mineral grains which are either weathered in place or transported from upslope areas with rainfall runoff. The energy expended by runoff water in soil transportation and accumulation is not quite enough to transport all of the sediment to make the vast quantities of soil. Some of the energy to move sediment and create soil derives from the energy it took to lift the rocks up, millions of years ago, to whatever elevation above sea level they are; it is tectonic energy - Earth's interior energy. It becomes potential energy which is released when the eroded sediments are mobilized by rainwater - filling depressions, making the basis of soil. Think of it like a heavy book which has no inherent energy to make nose. Until you put that energy into by lifting it up to some point above the table top. It now has energy which you can prove by letting it go and listening to the noise it makes when it returns to the elevation it was.

I won't go into the Sun's energy input here - that's another post.

Hopefully this little snapshot shows that, at some fundamental level, the actual Earth and its inhabitants are symbiotically intertwined (See Status Quo, below the fold). So the weak Gaia Hypothesis has some modicum of merit, as I said earlier. Personally, I don't buy it for many reasons. But back to the point. What was disappointing about Avatar?

The story followed a really consistent weak Gaia Hypothesis thread for most of the film. It was good because, even if I don't accept the hypothesis, it was a consistent position and a good, not-too-hokey presentation of the weak Gaia Hypothesis.

UNTIL.... dum - dum dahhhhh.

The fight with the nasty old humans from the mining concern rages when the spirit of Pandora rose up to assist its biota. ANTHROPIC PRINCIPLE!!!!!!!! (See Time and Place). Strong Gaia Hypothesis alert. The planet itself took an active role and ensured its organisms cooperated to repel the parasite which was desecrating the Gaian being.

I won't even go into the bit about the planet taking an active role in the permanent body switch.

The weak hypothesis is not too bad a way of looking at the world and our place in it. It really does make one feel a part of the world despite living in civilized conditions. But the strong hypothesis is nothing more than another religion - and not an original one either.

I suppose I could go on, but I can sum it all up with one word:

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