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Why Man Needs Open Space

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The Basic Optimum Human Environment: Human Ecology

Involvement with nature, a nearly universal trait among both primitive and civilized peoples, may be in part genetically determined; human needs for natural diversity and beauty must be inherent. Man’s love for natural colors, patterns and harmonies, his preference for forest-grassland ecotones which he recreates wherever he settles, must be the result to a large degree of Darwinian natural selection through eons of mammalian and anthropoid evolutionary time and even through the ten millenia of human agricultural history. Our eyes and ears, noses, brains, and bodies have all been shaped by nature.

Would it not then be indeed incredible if savannas and forest groves, flowers and animals, the multiplicity of environmental components to which our bodies were originally shaped were not still important to us? Would not such a concept of nature be a major part of what we might call a basic optimum human environment?

Preserving Optimum Environments

One could elaborate this insight in a thousand obvious as well as more subtle ways: yes, air to breathe, water to drink, plants and animals to hunt and eat, sounds to hear, images to see, textures to touch, land to wander on. Does not spring, with sprouting meadows and flowering trees stimulate joy? Do not then lovers go courting in the country, flowers in hand, sensitive as never before to the feel of the awakening, growing land, to every odor of blossom, intoxicated with the dark, demonic urges to dance, to touch, to mate close to the earth? And do not boys and girls fish, men hunt and fight, both men and women garden? Do we not, if we have money, build swimming pools or greenhouses, or second homes in the mountains? Do we not stream out of our cities by the millions to camp in nature every spring and summer? Do we not, if we have a choice, keep pet dogs, cats, or fish, Cyclamen, Primula or Begonia, and flickering fireplaces to alleviate our miserably cold northern winters, as ethnological fragments — almost symbolic bits — of that ancestral ecosystem which shaped our physical needs and subconscious desires? Could this also be the reason why some of us get seduced by surrogate plastic flowers or plastic trees? Is it to satisfy such basic, innate needs that we wish to keep in touch with nature? If there is a biologically valid concept of a basic optimum environment for mankind, would it not have to include much real nature? Is not this optimum human environment definable in its essence as a compromise containing maximum contact with nature without giving up all the advantages of culture and civilization? Would not human needs for this nature contact be of different intensity and quality for different ontogenetic stages: water, mud for babies, shrubs to hide behind for six-year-olds, fields to dig in and grass to sleep on for adolescents and adults? How long since we left the savannas? the tribes? the villages? Surely not long enough for all of us to have lost all need for their natural settings.

Here, finally, is an argument for nature preservation free of purely utilitarian considerations; not just clean air because polluted air gives cancer; not just pure water because polluted water kills the fish we might like to catch; not just saving plants or ducks because they could be useful or edible; but preservation of the natural ecosystem to give body and soul a chance to function in the way they were selected to function in their original phylogenetic home. The ultimate argument for nature preservation, as well as for landscape architecture or urban planning, rests squarely on evolutionary principles.

Urbanization Forces Adaptive Change

I believe that the optimum environment of any organism, whether man, grasshopper, water lily or amoeba, is the environment in which it evolved. Most of us city dwellers live in a human environment which is but a few thousand years old. Today about fifty per cent of the world population lives in towns. Many of these people live in metropolises which are not optimum environments by any stretch of the imagination. In them they are like wild colts which evolved to roam the steppes but are tethered in a dark cave. Unlike rapid cultural evolution, psychological and physical evolution is an immensely slow process in which a hundred and sixty years (eight sexual generations) will produce at best only the most minute and imperceptible changes in our basic adaptations.

Today, we are still evolving; perhaps even more rapidly since the industrial-urban revolution, in response to urban selection pressures. But whither, and to what final fate no one can say. Perhaps in twenty thousand years we may evolve into a half-blind, half-deaf Homo sapiens subspecies, post-sapiens, composed of environmental morons programmed to tolerate pollution, noise and ugliness, and perhaps allergic to the confusing diversity of natural conditions. But today we are still a part of Homo s. sapiens, a subspecies with strong genetic needs for the natural environment, whose members try at every turn to find nature surrogates, from air-conditioned humidified domiciles to aquaria with fish, to plastic trees designed by well-meaning landscape architects. 

Clearly, the finest human and artistic attributes of even the most civilized man and culture have their roots in nature. Judging from the intensity of man’s feelings and his search for substitutes we may yet preserve these roots and their substrate as the basis of his humanity. The substitutes we find for our original habitats are legion, and many are important and satisfying. Clearly, we cannot all go back to the African savannas, for there are too many of us! And even if we could we would not want to — for most of us may have lost the ability to live and hunt like cavemen. Yet if we wish to experience a highly optimal physiological-psychological environment, we must retain the option of replicating the environment of our ancestors tens of thousands of years ago. And that means a return to biotic diversity and adventure, reaching from the simplicity of a colorful flower garden all the way to the unmanipulated, undepleted complexity of a wilderness. Above all, it means the opportunity for intimate sensory contact with natural beauty, both cultivated and wild. We do need well-kept colorful gardens as we do fields of grain and fiber. But to me, in terms of sensory contact, these are only special substitutes for wild land, with crucial yet limited functions and usually with low diversity.

Today, for the sake of diversity, we have even more urgent reasons to preserve the many, many species of plants and animals which cannot be grown in gardens or maintained and reproduced in zoos. Except for a few domesticated species, this can only be done by protecting their original wild habitat, by preserving the very special ecosystem to which each species is adapted and of which it is a part. But today it is not enough to pay homage to human love for nature, nor to art’s dependence on nature, but rather high time to press for experimental proof and scientific understanding of the why and the how, and thus furnish the factual scientific-mechanistic bases and arguments for the deliberate preservation of the natural environment.

Human needs for nature surely cannot be disputed. Because we evolved in it, this, the biosphere, is the best of all possible worlds for us; and if we lose it, or pieces of it, no one can predict the consequences. However, these cannot, in the long run, be good. Just to look at our urban problems is to glimpse a dark, hellish future.

It is common knowledge that denatured human environments produce denatured (i.e. unnatural) humans. This is demonstrated over and over again in our crowded inner cities. It may be, as many technological optimists defending larger populations have hopefully repeated, that crowding alone, isolated from any concomitant side effects, exerts no particularly bad sociological influence on most people. But if so why then, are so many of the most terrible modern human problems endemic to the crowded urban centers? If the cause is not crowding directly, perhaps it is crowding indirectly. Perhaps intense crowding, which results in the destruction of all complex biological ecosystems, indirectly deprives man of a whole battery of inherited needs which can be satisfied easily and well only by nature. To put it another way, since crowded places tend to be denatured, wouldn’t this seem to support the ideas presented here: Namely that humans cannot live very well without the biological diversity of nature, and especially without the beauty and pattern of plants to view, to explore, to be stimulated by.

Maintaining Human Ecosystems

This is why we need so many nature preserves whether small scientific areas and country parks or giant wilderness areas of immense size; because there are SO many species and ecosystems to be protected. This is why we need international agreements on animals and ecosystems, subsidies and concerted efforts for the preservation of the tropics and the oceans on a scale as yet hard to imagine. This is why every citizen must be passionately committed to the establishment and protection of biotic preserves of whatever size. In arguing for preservation of nature, the diversity of wilderness is not the only concern today. We need to preserve human ecosystems showing high diversity, stability and natural beauty. Thus apple or peach orchards, vegetable plots and fields of specialty crops such as artichokes, or small, low-yielding but diverse farms on the outskirts of cities are all agricultural communities, essentially ecotonal in character, combining forest and grassland into a kind of anthropogenic savanna of great aesthetic and ecological value. Such small farms with many kinds of crops and groves of trees are quite stable. Now much of such land is being deliberately subdivided in the name of growth and profit or developed and destroyed in the name of progress.

Planners, especially, need to explain to the public the elusive meaning of this loss to man and offer them viable alternatives: statutory limits to the growth of suburbia, the benefits of good zoning, with changes in taxation structure to allow farming next to apartment houses and above all, a deliberate policy of restraint on growth and on making money out of the selling of land.

Human Needs Linked to Natural Diversity

The general malaise of mankind, especially of Western civilization, would make it appear that urban humanity has become the unhappy involuntary guinea pig of a giant experiment in sensory deprivation in which the crowded cities are our cages. Increasingly, a larger proportion of mankind is suffering from the inexorable, cumulative acceleration of technology and the loss of the experimental variable in nature. No one force is exclusively to blame — not technology per se, not capitalism, nor overpopulation. But the syndrome is such that no one is exempt from the effects. While we have reached much higher material standards of living and a longer life expectancy, there are other basic measures of an optimum environment; measures which would make it appear that we are reaping the synergistic effects of sensory deprivation on a gigantic scale.

Examples of a gradual collapse of social structure and of a biological incoherence are legion, including crowding, pollution, and the unbearable, continuous roaring noises of the large city. Significantly, recent research has shown mental disease to be twice as high in New York City as in rural northern Illinois; a not unexpected conclusion. If we even cursorily analyze the difference between these two habitats of man, New York City and northern rural Illinois, we find that in addition to the lack of noise, pollution and crowding in the latter area, there is the presence of beautiful green plants, all combined into an infinitely varied landscape. Could it be that the stimuli of non-human living diversity make the difference between sanity and madness? If so, is it not about time to find out why? Is it not finally time for experimental psychologists, human ethologists, and landscape architects and urban planners to get together and design experiments, scientifically indisputable and clinically impeccable, which would give us insights into how the brain of the human animal reacts to natural diversity, to natural beauty, to technological sterility: What exactly happens when we look at the symmetrical pattern of a leaf or smell the odor of a brilliant flower? With modern electroencephalogram (EEG) equipment and a little imagination, it would be rather easy to design experiments, using a diversity of groups of different ages with diverse social and ecological backgrounds; comparing children with adults, farm youngsters with high-rise apartment dwellers, the emotionally healthy and the mentally sick. Hardly anything is known about the way we neurologically relate to our surroundings. Could it be that we don’t want to know? That if the truth were out, many of the powers that be would then be forced to stop making a desert out of the green earth?

The truth of the matter is that hardly anyone has bothered to think about the connection between the alarm of the preservationists, the social pathology of the cities, and the overwhelming ignorance regarding human needs in general for the aesthetics of nature. There have indeed been no efforts made to establish in a scientific way just how this interrelationship functions. Yet wise men since time immemorial have subjectively sensed the important relationship of human happiness to natural conditions and incorporated it into ethics and religion. And artists have had it in their bones since the beginnings of recorded cultural time in the torchlit caves of Lascaux.

I realize that civilization produces its own unique brands of diversity. But especially compelling and significant for man, I feel, must be the incredibly rich diversity of the 400,000 species of plants and four million or more species of animals which combine and recombine endlessly into a vast array of variable biotic communities. From all indications, this visual natural diversity is especially meaningful to man (witness how at the earliest ontogenetic stages children compulsively search for it). It is well to stand in awe before this variability, which is of a magnitude technology cannot reproduce.

Homogenization Threatens Our Future

Will mankind have enough sense to preserve the complexity and diversity of nature? The current rate of heedless homogenization of the world’s once diverse environments is not encouraging. The transformation of natural diversity into cornfields, cow pastures and concrete cities the world over appears almost inevitable. Growth of both population and of technology implies bigger and grimmer megalopolises. It condemns future generations to becoming permanently locked into de-natured, polluted environments. If we value human intelligence, its superb sensitivities and deep emotions towards nature, and the happiness which flows from it, we had better begin to value more highly the natural diversity which still happens to exist and preserve it. For I believe, by whatever route we approach the modern human problem the answer is always the same: Preserve nature, for it is sacred to humanity and its evolution.


Dr. Hugh Iltis was a professor of botany and director of the herbarium at the University of Wisconsin–Madison. While most noted as a scientist for his role in the discovery of a perennial teosinte (Zea diploperennis) – a wild relative of modern maize (Z. mays) – he is also remembered as an outspoken environmental environmentalist and conservationist who championed the preservation of threatened habitats to protect biodiversity. Along with colleagues at the University of Guadalajara, he campaigned to protect the natural environment of Z. diploperennis through the creation of the 345,000-acre Sierra de Manantlán Biosphere Reserve. In 1960, he cofounded the Wisconsin chapter of the Nature Conservancy, and helped establish Hawaii’s Natural Areas Law of 1970. As one of the leaders of the campaign to ban the “toxic, dangerous to the environment, [and] likely carcinogenic” insecticide DDT in Wisconsin, he contributed to its becoming the first US state to do so, in 1968. He also called for a moratorium on logging virgin timber in the state. Read more about his life and career here.


Republished from The Urban Setting: Man’s Need for Open Space by Program in Human Ecology, Connecticut College (1980).

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