Thursday, September 26, 2013

Just a wee bit more about geologic timescales

Tappan Zee,  Hudson River, New York
 Looking North. The Tappan Zee was carved out of the 220 million year old Newark basin sandstones when glaciers carved the Hudson River Valley during the quarternary glaciation. The Palisades—the cliffs on the left side of the river—are basalt flows of lava that represent the eastern side of the rift that split the Continental Pangaea into North America, portions of Iceland, and Africa.

 Species evolution is determined in geologic time scales. There was never a “first” bird, just as there was never a “first” whale. At any given time, all a human observer would be able to see was a particular creature, occupying a particular niche, which might or might not display some or all of the characteristics of birds or whales.

 Human beings are time-bound by very narrow constraints lasting through, from the individual perspective, a single generation. Historical perspectives afford us a somewhat longer view, but, aside from the fossil record, our experience of living species and what they mean is restricted to our immediate environment and what we can see now. The practice of paleontology and the study of fossils is exotic enough that only a tiny portion of mankind studies it; and it is patently impossible for anyone to predict the future evolution of species.

 As such, we see everything through a tiny, more or less contemporary lens, and consequently feel relative alarm about the loss of individual species or the invasion of a local habitat by a foreign species. (We are, on the other hand, very comfortable with importing specific foreign species and planting them in our gardens—landscapes all over the world are populated with countless numbers of foreign species. Foreign species only tend to cause alarm when they successfully outcompete local creatures or plants. Our habit of moving species around because of their aesthetic values—pets, zoo animals, and exotic landscape plants—has resulted in any number of species invasions, most of them irreversible.)

What we tend to forget is that speciation and evolution take place on geologic time scales, that is, over tens and hundreds of millions of years. These forces are most definitely not under human control, but our interest in micromanaging species events has grown steadily with the environmental movement. While the movement is inarguably well-meaning, and its interest in in preserving biodiversity laudable, our habit of fighting pitched battles in what are going to be objectively losing situations is expensive and pointless. Battles must be fought; slowing and even stopping the extinction of whale species is a wise action. But this does not mean that stopping every invasive species makes sense; or that every species needs to be preserved. Only hubris leads us to believe that we are in control of the natural environment, or have any say whatsoever over the direction that develops in the long-term. Our habit of perceiving ourselves as separated from the natural environment, rather than being—indubitably—a product of it, and an integral part of the way in which it is evolving, has caused us to believe we have powers that don't in fact exists.

If the earth is taking evolutionary directions at the hand of man, these directions are in some ways just as much a natural product of the earth's overall evolutionary pattern as any other direction things might take. That is to say, argued from a cynic's point of view, habitat destruction, pollution, and the extinction of species is a natural phenomenon arising from the habits of a particular product of evolution, and has to be included, in a macroscopic view of the situation, as an entirely natural and acceptable phenomenon.

 Logical reasoning of this kind, which is difficult to refute, gives cold comfort to people like me, who prefer to see living things valued and preserved. I'll admit that perhaps it's the artist in me that believes that there is a fundamental goodness and aesthetic value in nature; and perhaps my affinity for nature itself begins with this aesthetic value, which for me is largely spiritual, rather than commercial or utilitarian. But if the aesthetes are not willing to preserve nature, who will? Those who view it as a commercial or utilitarian opportunity see little value in anything but its exploitation.

 The geologic timescale needs to be applied as a rough measurement of the significance of any evolutionary event, since it can only be measured from that perspective. Indeed, our alarm about the acceleration of extinctions arises specifically because of its association with geological events, the last 5 of which produced extinction rates that drastically altered the planet.

Here, self interest kicks in; what really worries human beings, after all, isn't whether other creatures will survive, but whether they themselves will. And this is a legitimate question. Yet once again, the preservation of individual species does not become the issue here. It's the overall health of the habitat that will ultimately determine survivability for both humanity and other organisms. This may not be seen on geologic timescales, but it is touched on them, because it involves landscapes and weather—both geologic forces—not salamanders and grasses. If the landscape is more intact, and more attuned to weather events, the preservation of canopy, groundcover, coastal buffer zones, etc., both mankind and the habitat benefit. The landscape is better able to absorb, process, and digest the results of man's activity, and the creatures that live in it are better able to survive accordingly.

 Civilization is peppered with the remains of earlier civilizations that believe they could manage nature effectively. Every single one of them ultimately came up against weather events they did not have any control over; in most cases, it led to a collapse. The bottom line is that our idea of how much control we have over our environment is exaggerated.  For example, when the US government undertook the massive water management projects in the western states at the beginning of the 1900s, after spending the equivalent of hundreds of billions of dollars, and building countless dams, the amount of arable land was increased by a paltry 1% or so at best, and it turned out that even this meager improvement was marginal and difficult to sustain over any long periods of time. One of the world's largest environmental engineering programs has been, in other words, of little value. The majority of the West is, as it always was, desert of one kind or another. Other major transformational projects such as Egypt's Aswan dam have proven to be equally suspect in the long run; if they do succeed in altering the local environment, as the dam did, they do so only at great expense, inflicting substantial long term damage in order to achieve what are fleeting, short term successes.

The odds are that the vast majority of human attempts to micromanage ecosystems and environments will, over the very long run, have a weak effect–that is, they will be nearly 100% ineffective, to the point where results will not be discernable.

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