Evolution and the ecosystem

Abstract

Long-range stability in natural communities is mediated through avenues of communication. One of the most important pathways of communication involves nutrient exchange, although other types of communication are suspected as being of considerable importance. The potential role of special "regulator species" in community stabilization is discussed and illustrated with two original examples, one dealing with brackish-water communities of the North Carolina coast, and the other dealing with communities of the piedmont streams of eastern Mexico. The significance of multi-species groups in evolution is also considered in the second example. It is suggested that the functional ecosystem is the fundamental seleclional unit of evolution and that evolution proceeds by mutual adjustment of ecological entities into harmonious systems with some degree ot permanence. © 1970 by the American Society of Zoologists.