In William Blake’s famous poem, “The Tyger,” Blake asks, “Did he who made the Lamb make thee?”
When the stars threw down their spears
And watered heaven with their tears:
Did he smile his work to see?
Did he who made the Lamb make thee?
The answer is, emphatically and unequivocally, “Yes!” The reason is because when a species of herbivores like sheep live in an area without any predators to keep their population in check, they proceed to multiply until they eat all the plants on which they feed so that the plants cannot reproduce or grow fast enough to maintain their numbers, which in turn leads to mass starvation deaths among the sheep. This is true of some wild herbivore populations, such as those that have been introduced on islands where they have no natural predators, or the tens of thousands of wild horses in the western United States that have no natural predators, first, because they are not indigenous to the region, and second, because all large potential predators, such as wolves and cougars, have been eliminated by human beings. Predators like lions, tigers, wolves, bears, coyotes, crocodiles, eagles, owls, sharks, seals, snakes, and whales are needed to keep their prey in check and thereby maintain the balance that every ecosystem requires in order to endure, while allowing the largest number of different organisms to exist and multiply.
Disease, which is caused by microscopic organisms like viruses and bacteria, is another way that Nature limits a species’ numbers and prevents them from becoming too numerous. Thus, there are big predators like lions and whales, and then there are microscopic predators if the first either don’t exist in a certain region or aren’t able to do their job effectively. Both of them perform the same function, which is to prevent the members of any species from becoming too numerous and thereby disturbing the balance that Nature requires in order to maintain itself optimally.
Interestingly, these two different kinds of predators generally work best in opposite situations: big predators prefer to isolate their prey before they devour it, while microscopic predators are most effective when populations are dense, that is, when they have become too numerous, so the disease-causing microbes are able to move easily from one member to another, which they cannot do when their prey are too far apart. Some human examples are when a plague called the Black Death ravaged the populations of many European cities in the 1300s and 1400s,[1] and the influenza epidemic following World War One, which killed an estimated 20-40 million people worldwide.
Before human beings became dominant and began to disturb ecosystems all over the world – systems which had existed for long periods of time – each ecosystem had achieved a marvelous and highly complex balance between all its living members, a balance that, by not favouring any one particular species, enabled the largest number of species not only to survive but to thrive and proliferate.[2]
Because of our limited understanding and our temporal nature, until recently, we humans have generally overlooked this harmonious and symbiotic interconnected existence of all life forms. Because we tend to look at Life as it is manifested in its particular discrete forms – as oak trees and butterflies, amoebae and hummingbirds, sharks and salmon, or bats and mosquitoes – we fail to see that all these discrete forms of Life are mutually dependent on the other life forms that exist in their vicinity. These kinds of cooperative relationships are obvious in the case of the insects and animals that pollinate flowers so they are able to reproduce, where both species benefit, but it is much less obvious to us in the case of predatory relationships like those between cats and birds, sharks and salmon, lions and antelopes, and malaria and human beings. For these predatory organisms serve as a vital means of population control that counteracts the natural fecundity of Nature. By preventing the explosion in the numbers of any given species, which would be the result if its members had no predators, they are both necessary and beneficial to those organisms whose numbers they limit.
Our myopic human understanding leads us mistakenly to believe that when a predator like a lion catches and devours a prey like a lamb, only the lion benefits from this outcome. What we fail to see is that, although the particular lamb that is killed and eaten does not benefit, the species of sheep to which it belongs benefits by having its population kept within sustainable limits. So, in every predator-prey relationship that is balanced – which the human predator-prey relationship most certainly is not[3] – both the predator and prey benefit when the former consume some of the latter.
The removal of a predator changes an ecosystem’s dynamic balance, sometimes radically. For example, in the nineteenth century the sea otter (Enhydra lutris), which lived in giant kelp “forests” off the western coast of North America from the Aleutian Islands in the north to southern California, was hunted for its pelt. Otters feed mainly on sea urchins, so when the otters became locally extinct, the echinoderms thrived and their populations first increased. However, the multitude of urchins decimated the kelp beds until no organisms remained, including the urchins themselves, since they no longer had anything on which to feed. The entire kelp ecosystem collapsed—algae, crustaceans, fish, sea urchins, squid, whales, and other organisms disappeared. For this reason biologists call the sea otter a keystone predator; without it the ecosystem literally falls apart.[4]
Or take this example, made famous by Aldo Leopold. Culling wolves from the Rocky Mountain Front Range seemed a good thing to do for cattle farmers. Yet killing off wolves saved deer and elk from a major predator. They proliferated and in turn ate the countryside clean of its groundcover and first eight feet of foliage. This in turn made the land less capable of trapping runoff water, and so mountainsides began to lose soil at an alarming rate. The indirect effects of killing wolves had serious ecological consequences affecting farming and native habitats.[5]
No matter how evolved we become and no matter how much scientific knowledge we accumulate, human beings will never be able to create anything comparable to the extraordinary, complex systems that exist in many parts of the world, which consist not only of living creatures but also of what we call inanimate processes such as the tides caused by the gravitational attraction of the Moon, the ocean currents that circulate vast quantities of water, nutrients, and heat around the globe, the evaporation of water from the Earth’s surface and its later condensation in the form of rain, or the slow but nevertheless vital erosion of rocks so their minerals are separated into a form that plants can incorporate into themselves so they can grow and make these minerals available to other life forms that consume them.
But though we are not capable of creating anything like these truly wondrous systems, we are quite capable of marring, disturbing, and destroying them. Like a selfish, impulsive, and heedless child that delights in causing havoc to the things that it does not value or understand, we humans, having become enamoured of ourselves and our many artificial inventions, go about the Earth, marring and defiling pretty nearly everything with our cursed industrial, scientific, and technological touch. Instead of giving life, we destroy it wholesale; instead of improving, we make worse, less abundant, more ugly, deformed, polluted, and impoverished the systems that we had no hand in creating and perfecting. Where there was formerly Life and beauty in abundance, we instead bring death, poison, disfigurement, and desolation.
And for what do we destroy all this natural beauty and abundance? For the sake of our paltry inventions and this thing we call civilization, which we in our colossal conceitedness regard as something greater, nobler, and more important than the Nature that we destroy in the process. Truly there is no greater proof of our profound immorality than this, that we are not even able to judge which of these two creations – the one that is non-human and is living, vital, sustaining, nourishing, generous, and has endured for billions of years, while the other that is human and is dead, inanimate, selfish, destructive, poisonous, and will, at the rate that we are going, endure in total for a mere few thousand years before it will be reduced to the dust from which it arose, to be heard no more – is the greater and more important. That so many of us have turned our backs on the glorious Creation of the Creator, preferring instead our petty, vulgar, vicious, vacuous, inane, lifeless, and destructive human creations, is our greatest collective sin, a sin that will be punished by our destruction if we do not change our ways.
The most fearsome predatory animal ever to walk the face of the Earth during its very long history is not the lion or the tiger, the bear or the wolf, the giant python or the shark, the crocodile or the whale, or even the misnamed tyrannosaurus rex: it is we human beings who, by our ingenuity and cleverness, have removed all the natural restraints that keep the numbers of all living organisms in check, thereby limiting the damage that they can cause to the fertile Earth and the many other living creatures that inhabit it. To paraphrase William Blake,
Human! Human! burning bright
In the forests of the night,
What immortal hand or eye
Could frame thy fearful symmetry?
In what distant deeps or skies
Burnt the fire of thine eyes?
On what wings dare he aspire?
What the hand dare seize the fire?
And what shoulder, & what art,
Could twist the sinews of thy heart?
And when thy heart began to beat,
What dread hand? & what dread feet?
What the hammer? what the chain?
In what furnace was thy brain?
What the anvil? what dread grasp
Dare its deadly terrors clasp?
When the stars threw down their spears
And watered heaven with their tears,
Did he smile his work to see?
Did he who made the Lamb make thee?
Human! Human! burning bright
In the forests of the night,
What immortal hand or eye
Dare frame thy fearful symmetry?
[1] It is estimated that this deadly disease reduced the population of some European countries by about one-third. What this means is that, even at that relatively early point in humanity’s recent rise to global dominance, in Nature’s estimate, our numbers were already too numerous in some parts of the world, a trend that has only worsened in recent times.
[2] It would be a mistake to regard this natural balance as something static and unchanging that, once achieved, remains in that state forever. Just like the organisms that comprise it, the balance that is found in stable ecosystems can also change gradually with the passage of time, with some organisms becoming more dominant for a period than others, or the development or introduction of new species. Moreover, just like a living organism, these systems can withstand stresses, damage, harm, unexpected occurrences, and even natural disasters and storms, while repairing themselves, provided the harm is not too great.
[3] Apart from humans, there is probably no other predatory species that is able to catch so much of its prey as to cause its extinction. Even before the industrial era, during which our destructive effects on other living creatures has been greatly accelerated, it is likely that our ancestors hunted a number of large mammals and birds to extinction, including ground sloths, giant beavers, and large flightless birds like the moa.
[4] Wisdom for a Livable Planet by Carl N. McDaniel, p. 46. Trinity University Press, San Antonio, Texas, 2005.
[5] The Ecological Life: Discovering Citizenship and a Sense of Humanity by Jeremy Bendik-Keymer, lecture two. Bowman & Littlefield Publishers, Inc., Lanham, Maryland, 2006.