From the beginning of man's exploitation of knowledge and technology he has improved his own chances for survival and reordered the environment to suit himself. In most instances, these dual goals have been accomplished at some price to the environment.

There is no evidence that in his early exploitation of technology man was any less cruel and senseless than he is today. Early history supports the hypothesis that man evaluated each new discovery in terms of its death-evoking potential to his enemies and his own survival. Later, as knowledge and particularly as language developed, technology as a means of producing wealth predominated. With every advance in technology the planet was further plundered as its wealth was discovered, and these discoveries led to the costly political struggles in which the newest technical devices pitted man against man for control of the world's wealth.

Today, the United States is extolled as a leading example of technological development and enlightenment on the one hand, and, on the other, is castigated for using an unfair share of the world's resources to sustain that standard. Japan is emerging as a high technology nation through the exploitation of scientific and engineering development, but the price is high in terms of stress-induced mortality and in pollution. Simultaneously, Japan is enjoying a standard of living unprecedented in the Orient.

The most technically advanced nations—West Germany, the United States, and Japan—all have the most severe pollution problems as well as the highest standards of living. But it can be argued whether the cost in ecological impairment is justified by the benefits derived from this highly industrialized condition.

The onward rush of technology raises a number of serious questions for the future. Where will new sources of energy come from to drive the machines of technology? Will the water supply last? Will there be enough minerals to satisfy technology's insatiable appetite? Will the continued pollution of the air make city life untenable? Will development destroy all of nature? Will the nation be paved from coast to coast? Will the wilderness or any natural area survive? Will cities perish in their own waste, filth, and crime?

Technology did not release man from the natural ecosystem but involved him in a new one. Biologically he changed little but he modified his environment through the use of tools. The ecosystem concept did not change either but new factors were introduced in the form of man and his tools. Man's ecosystem does not differ from other ecosystems, except for the proliferation of technological devices that directly and indirectly aid man in ordering and controlling his environment and producing wealth. Thus, technology in the hands of man became a new, potent ecological factor.

As an organism, man responds to the same biological and physical factors as always but modern man has altered the human environment with his technology and this has affected him. For example, vaccination against smallpox and the pollution of rivers with agricultural and industrial wastes are two diverse ways in which technology has altered the human environment.

Man's basic requirements for survival do not vary from place to place nor from time to time. As a biological organism he is a mammal and has mammalian requirements—he must obtain food, reproduce and avoid predators, provide protection for the young until they reach the age of reproduction, and so on. The presence or absence of technology allows man to control the environment and provides a high potential for its destructive degradation. As technology has increased, man's control over the environment has increased and so has his need for energy.

Man has always been part of an ecosystem. in earlier days he lived and died in a predator-prey relationship, but with the advent of technology, man, for the most part, freed himself from his predators. Once free from predators, man could concentrate on improving his chances of survival by husbanding food—either through hunting or agriculture—and by securing his environment and modifying it to suit his needs.

Primitive men in primitive societies lived more harmoniously with the environment. Having no way to change the environment, they adapted to it and lived in harmony with it. Even so, primitive man may have altered environments to some extent. Setting fires, for instance, may have been a simple method for altering environment, particularly in the prairies, the onset of agriculture. But it remained for modern man with his technological devices to dramatically alter the environment, and in so doing he has psychologically attempted to place himself outside the ecosystem and ignore the effects of his technology. Modern man must recognize that he is an indivisible part of the biosphere, that everything he does affects it, and that the enormous quantity of energy available to him is a potent factor that cannot be ignored.

The communities of man fit all the requirements of ecosystems. They have elements that stabilize them and those that destabilize them. Communities of man that are diversified tend, like communities of plants and animals, to have great stability. Those that are simple tend to be unstable depending upon the factors that impinge upon them. One need only compare a great city with many sources of employment and wealth production with one-industry towns to recognize the relationship between the ecosystem of man and the ecosystem of other organisms. Ecologically they are quite similar.

The principle of ecosystem dynamics is that ecosystem stability depends upon the flow of energy into the ecosystem, and as the system optimizes its use of energy it becomes stable. All ecosystems are either at a steady state condition and have great stability, or they are approaching the steady state, or they have passed the steady state and are going into a decline. The steady state represents the balanced use of the energy available to the community in relation to the factors influencing it. In exactly the same way that equilibrium condition makes possible the thermodynamic analysis of energy systems, so the ecological steady state makes possible the analysis of ecosystems. The ecosystem steady state is the thermodynamic equivalent of "balance of nature."

A number of prerequisites for ecosystem analysis are necessary. The first is to recognize the steady state when it is achieved, and the second is to recognize developmental stages on both sides of the steady state. It is necessary to understand that as long as uniform or stable physical conditions persist, the ecosystem will reach and maintain steady state in relationship to those factors. And it is equally important to recognize that, in addition to the usual factors, i.e., sunlight, rainfall, wind, temperature, water, and the seasonal distribution of these factors, man, even without his technology, is an important ecological factor. With his technology he becomes a formidable ecological factor for both good and evil.

Man can move mountains, pollute lakes, replace the tall grass prairie with corn, and convert the eastern deciduous forest to farms and finally to a megalopolis, It is interesting to consider that in the tall grass prairie, tall grass—big bluestem or Indian grass—was replaced by another tall grass, corn, and that the ecosystem that developed is as stable as the ecosystem that it replaced.