Concerning Community Symmetry

Abstract

Paralleling the study of organisms, the study of communities may be separated into several artificial categories. A community may be said to have structure. This taxonomico-morphological a spect was the first phase of modern ecology and culminated in the description of community types. This necessary work has been largely accomplished, just as in general morphology of organisms the main outlines have been delineated. Description of the unusual type of community, or community structural detail, will naturally continue, as will the description of new species of organisms, or minute structural details of organisms. Second, the community may be said to have a genetico-evolutionary aspect and here the questions asked are concerned with the identity of the ancestral community, or with the future development of a community. The study of these developmental processes, succession or community evolution, has followed closely the work on community anatomy, and like the latter, the framework has been largely constructed. Third, a community may be said to have a physiology-the study of many functions within and of the whole, culminating in a study of what is called the superorganism, recently examined by Emerson ('39). It is with community physiology that this paper is concerned. Naturally enough the writer's research program on animal activity for the past twelve years (Park, '40) has influenced his reflections upon the integration of the community. For example when I have observed the animals in a forest I have been overly conscious of the imponderable numbers of organisms in terms of their multiform, specifically peculiar, periodic and aperiodic activities. This function pattern was so complex that it defied analysis in toto. A given part could be analyzed, but the stream of activity and interrrelation swirled on about the segment being analyzed, and ultimate continuity with the whole pattern was deranged or lost. The larger the segment analyzed, the less this loss of integration but the more dilute the analysis. The employment of our large and still growing terminology explained nothing. Similarly the use of mathematics, although an excellent tool in skilled hands, was of no value as a mental telescope. These shortcomings were probably my own fault, yet the reality of the community as a whole continued to plague me, and the complex pattern defied complete realization. After considerable thought I have reached the conclusion that at least one unifying point of view is that there is a maximal utilization of space-time, eventuating in an arhythmic, symmetrical disposition of community activity with reference to the twenty-four hour day-night cycle. This concept will be considered at three levels of integration: the organismal, the infra-social, and the social. OrganismXal level.-In general where the environment is periodic with respect to day-night, habitat niches are occupied by animals whose general activity is periodically synchronized with this environmental rhythm. This periodism is specific and individual; it is composite, composed in part of endogenous rhythms which are partially habitual and partially inherent, and in part of exogenous rhythms. In so far as the exogenous activity is concerned, and indirectly the habitual activity, the present and past experience of an individual results from stimuli perceived through its sensory receptors. Underlying this composite periodic activity, which varies with the individual, with latitude and with season, and its concomitant effects on protoplasmic activity, are other vital functions which