Tuesday, March 27, 2012

724. E. O. Wilson: Why Care About the Crisis of Nature

The following is a slightly abridged "Why Care" (Chapter 4) of E. O. Wilson's The Creation. It presents a biologist view of why humanity should care about the current present-day crisis of nature.  Other views have been presented earlier and will be presented later.  K.N.

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Consider, then, the following truth, which because of its importance deserves to be called the First Principle of Human Ecology: Homo sapiens is a species confined to an extremely small niche. True, our minds soar out to the edge of the universe. And contract inward to subatomic particles, the two extremes encompassing thirty powers of ten in space. In this respect our intellects are godlike. But let’s face it, our bodies stay trapped inside a proportionately microscopic bubble of physical constraints. We have learned how to occupy some of Earth’s most hostile environments—but only when enclosed within airtight containers whose environment is precisely controlled. Polar ice caps, the deep sea, and the moon are ours to visit, but even slight malfunctions of the life-support capsule in which we travel can be terminal to frail little Homo sapiens. Prolonged residence there, even when physically possible, is psychologically unbearable.

Here is my point: Earth provides a self-regulating bubble that sustains us indefinitely without any thought or contrivance on our own.  This protective shield is the biosphere, the totality of life, creator of all air, cleanser of all water, manager of all soil, but itself a fragile membrane that barely clings to the surface of the plant.  Humanity, as Darwin observed at the close of The Ascent of Man, bears the indelible stamp of our lowly origin from preexisting life forms…

The First Principle of Human Ecology can be put another way: Alien planets are not inn out genes. If organisms exist on Mars, Europa, or Titanis, then these planets are in their genes, and those will surely differ radically from ours.

It follows that human self-interest is best served by not overly harming the other life forms on earth that still survive. Environmental damage can be defined contrary to humanity’s inborn physical and emotional needs. We are not evolving autonomously into something new.  Nor are we likely in the foreseeable future to change our basic nature by genetic engineering, as some giddily futuristic writers have envisioned. Scientific knowledge may continue to grow without limit, or it may not.  But either way, human biology and emotions will stay the same far into the future, because our immensely complicated cerebral cortex can tolerate little tinkering, because human beings cannot mutate like bacteria to fit every environment we spoil, and because, ultimately, finally and quite simply, we may choose to remain true to human nature, the heritage bequeathed us by millions of years of residence in the biosphere.

Here, then, is another argument for existential conservatism.  Beyond the curing of obvious hereditary diseases such as multiple sclerosis and sickle-cell anemia, by gene substitution, the human genome will be modified only at risk.  It is far better to work with human nature as it is, by changing our social institutions and moral precepts to get a more nearly optimal fit to our genes, than it would be to tinker with something that took eons of trail and error to create.

The problem of modern civilization rises from the disjunction between our ancient and glacially slow-evolving genetic heritage at one level of evolution and our ultra-fast cultural evolution at the other level.  There are still thinkers around the world, some in commanding political and religious positions, who wish to base moral law on the sacred scripture of Iran Age desert kingdoms while using high technology to conduct tribal wars—of course with the presumed blessing of their respective tribal gods. The increasing contrast of such retrograde thinking should make us more circumspect than ever, and not just about starting wars.  It should also make us more careful with the environment, upon which our lives ultimately depend.  It will be prudent to curtail the final and permanent obliteration of Nature until we understand more precisely what we are and what we are doing.

The destructive power of Homo sapiens has no limit, even though our biomass is almost invisibly small. It is mathematically possible to log-stack all the people on Earth into a single block of one cubic mile and lower them out of sight in a remote part of the Grand Canyon.  Yet humanity is already the first species in the history of life to become a geophysical force.  We have, all by our bipedal, wobbly-headed selves, altered Earth’s atmosphere and climate away from the norm. We have spread thousands of toxic chemicals worldwide, appropriated 40 percent of the solar energy available for photosynthesis, converted almost all of the easily arable land, dammed most of the rivers, raised the planet sea level, and now, in a manner likely to get everyone’s attention like nothing else before, we are close to running out of fresh water.  A collateral effect of all this frantic activity is the continuing extinction of world ecosystems, along with the species that compose them. This also happens to be the only human impact that is irreversible.

With all the troubles that humanity faces, why should we care about the condition of living Nature? What difference will it make if a few or even half of all the species on earth are exterminated? Many reasons exist fundamental to human weal. Unimaginably vast sources of scientific information and biological wealth will be destroyed. Opportunity costs, which will be better understood by our descendants than by ourselves, will be staggering. Gone forever will be undisclosed medicines, crops, timbers, fibers, soil-restoring vegetation, petroleum substitutes, and other products and amenities.

Critics of environmentalism (whatever that overused term means—aren’t we all environmentalists?) usually wave aside the small and unfamiliar, which they tend to classify into two categories, bugs and weeds. It is easy for them to overlook the fact that these creatures make up most of the organisms and species on Earth. They forget, if they ever knew, how the voracious caterpillars of an obscure moth from the American tropics saved Australia’s pastureland from the outgrowth of cactus; how Madagascar “weed,” the rosy periwinkle, provided the alkaloids that cure most cases of Hodgkin’s disease and acute childhood leukemia; how another substance from an obscure Norwegian fungus made possible the organ transplant industry; how a chemical from the saliva of leeches yielded a solvent that prevent blood clots during and after surgery; and so on through the pharmacopoeia that has stretched from the herbal medicines pf Stone Age shamans to the magic-bullet cures of present-day biomedical science.

Because wild natural ecosystems are in plain sight, it is also easy to take for granted the environmental services they provide humanity. Wild species enrich the soil, cleanse the water, and pollinate most the flowering plants.  They create the very air we breathe. Without these amenities, the reminder of human history would be nasty and brief.  The sustaining matrix of our existence is the green plants, along with legions of microorganisms and tiny invertebrates.  These organisms support the world because they are so genetically diverse, allowing them to divide roles in the ecosystem in a fine degree of resolution, and so abundant that at least a few occupy virtually every square meter of Earth’s surface.  Their functions in the ecosystem are redundant; if one species is eliminated, there is often another able to expand and at least partially take its place.  All together the other species, mostly bugs and weeds, run the world exactly as we should want it run, because during prehistory humanity evolved to depend upon their combined actions and the insurance that biodiversity provides world stability.

Living nature is nothing more than the commonality of organisms in the wild state and the physical and chemical equilibrium their species generate through interaction with one another.  But it is also nothing less than that commonality and equilibrium. The power of living Nature lies in sustainability through complexity. Destabilize it by degrading it to a simpler state, as we seem bent on doing, and the result could be catastrophic. The organisms most affected are likely to be the largest and most complex, including human beings.

More respect is due the little things that run the world. Being and entomologist, I will now use insects to plead the class-action case on behalf of the Earth’s entire afflicted fauna and flora.  The diversity of insects is the greatest documented among all organisms: the total number of species classified in 2006 is about 900,000.  The true number, combining those both known and remaining to be discovered, may exceed 10 million. The biomass of insects is immense: about a million trillion are alive at any moment.  Ants alone, of which there may be 10 thousand trillion, weigh roughly as much as all 6.5 billion human beings.  While these estimates are still shaky (to put the matter generously), there is no doubt that insects rank near the top among animals in physical bulk.  They are rivaled there in biomass by copepods (minute sea crustaceans), mites (tiny spider like arthropods), and, at the very apex, the amazing nematode worms, whose vast population swarms, probably representing millions of species, make up four-fifth of all animals on Earth. Can anyone believe that these little creatures are just there to fill space?

People need insects to survive, but insects do not need us. If all humankind were to disappear tomorrow, it is unlikely that a single insect species would go extinct, except three forms of human body and head lice.   Even then there would remain gorilla lice, closely related to the human parasites and available to carry on at least something close to the ancient line. In two or three centuries, with humans gone, the ecosystems of the world regenerate back to the rich state of near equilibrium that existed ten thousand years ago or so, minus of course the many species that we have pushed into extinction. 

But if insects were to vanish, the terrestrial environment would soon collapse into chaos.  Picture the steps of the cataclysm, as it would likely unfold across the first several decades:

·               A majority of the flowering plants, upon being deprived of their pollinators, cease to reproduce.
·               Most herbaceous plant species among them spiral down to extinction. Insect-pollinated shrubs and trees hang on for a few more years, in rare cases up to centuries.
·               The great majority of birds and other land vertebrates, now denied the specialized foliage, fruits, and insects prey on which they feed, follow the plants into oblivion.
·               The soil remains largely unturned, accelerating plant decline, because insects, not earthworms as generally supposed, are the principal turner and renewer of the soil.
·               Populations of fungi and bacteria explode and remain at a peak over a few years while metabolizing the dead plant and animal material that pile up.
·               Wind-pollinated grasses and a handful of fern and conifer species spread over much of the deforested terrain, then decline to some extent as the soil deteriorates.
·               The human species survives, able to fall back on wind-pollinated grains and marine fishing. But amid widespread starvation during the first several decades, human population plunges to a small fraction of their former level. The wars for control of the dwindling resources, the suffering, and the tumultuous decline to dark-age barbarism would be unprecedented in human history.
·               Clinging to survival in a devastated world, and trapped in an ecological dark age, the survivors would offer prayers for the return of weeds and bugs.

 The bottom line of my scenario is this: be careful with pesticides. Do not give thought to diminishing the insect world. It would be a serious mistake to let even one species out of the millions on Earth go extinct. That is, let me add quickly, with an extremely few exceptions.  I’d vote for the eradication of the aforementioned lice (the gravamen against them: limited to humans, serious skin pests, threats to quality of life, carriers of disease).  Also, I’d not mourn the passing of mosquitoes of the Anopheles gambiae complex of Africa, species that are specialized to feed on human blood, during which they transmit malignant malaria.  Keep their DNA for future research and let them go.  Let us not be conservation absolutists when it comes to creatures specialized to feed on human beings.

In the real world there is a need to control only the tiny fraction of inset species, perhaps as few as one out of ten thousand, that are consistently harmful to humans.  In most cases control means to reduce and if possible to eradicate populations of such species in countries where they are aliens, usually having been transported there by humans as unintended hitchhikers.  Take, for example, the red imported fire ant that has vexed the southern United States since the 1940s and has recently spread from there to California, the Caribbean islands, Australia, New Zealand, and China. It inflicts hundreds of millions of dollars in agricultural losses each year. Its stings are painful and occasionally fatal, usually as a result of anaphylactic shock triggered by the venom.  It has displaced some native insects and reduced wildlife populations. Obviously it would be wise to erase invading populations of the red fire ant—if only entomologists could find a way.  But the same is not true for southern Brazil and northern Argentina, where the ant is not imported but a native species, ecologically adjusted by millions of years of co-evolution with other native species.  In their South American home they are in balance with predators, and competitors.  Otherwise they would have become extinct ages ago.  In the United States their enemies are fewer in number and weaker.  Removal of the alien fire ant populations would be healthy for both people and the environment of the countries they have colonized.  Removal from South America, in contrast, might cause damage to the ecosystems in which they are co-adapted with other species and live harmoniously.

One of the daunting challenges of the modern discipline of ecology is to sort out such pluses and minuses of living Nature in order better to define the inner structure of the biosphere. There is hope that in time researchers will learn how ecosystems are assembled, how they are sustained, and more precisely how they come to be destabilized. Earth is a laboratory wherein Nature…has laid before us the results of countless experiments. She speaks to us; now let us listen. 

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