"One world," the political slogan so popular a generation ago, is no longer a viable issue, but "one world" as a biological phenomenon furnishes one of the most pressing issues of the day. Another word for this subject is "ecology," a term popular among biologists and gradually becoming better known among the laity. The word means the mutual relationships between an organism and its environment, that is, the way they affect each other. The concept, "balance of nature," is quite familiar. This indicates the way different animal species tend to keep each other in check, but ecology also includes the inorganic factors in the environment.
Physicians are familiar with the subject of "environmental health," with such obvious examples as lead or benzine or carbon monoxide or x-radiation, inducing disease in man. Conversely, some of the ways that man affects the environment are equally obvious—as cutting down forests or allowing the