Executive Director, Worcester Foundation for Experimental Biology, Research Professor of Physiology, Boston University Graduate School, and President, American Academy of Arts and Sciences.
THERE IS AMBIVALENCE about many scientific discoveries. It is ironical that man's most humane motives, supported by applications of advances in medicine and public health since World War II in underdeveloped countries, are primarily responsible for the population explosion and its accompanying grave dangers. In the next two or three days we shall discuss this problem and its demographic, economic and political aspects, and hear about research in the biology of fertility and its control. At this Session, I would like to limit my remarks primarily to some of the ways in which nature deals with over-crowding in animal societies.
In multiplying cultures of microorganisms the growth rate accelerates exponentially, but as toxic metabolic products, such as acids or alcohol, accumulate, the rate declines and the curve describing numbers of organisms as a function of time ultimately flattens off. These S-shaped growth curves for microorganisms have been described by equations aimed at elucidating the dynamics of such population growths.