Presidential address: The evolution of reproductive rates: Are there no Rules?
- Animal Ecology Division, D.S.I.R., Lower Hutt
During the past 20 years animal ecologists have spent much time trying to understand population processes, the practical implications of which are vastly more important for our survival on earth than are all our extravagant efforts to leave it with a safe return ticket. In this period a handful of authoritative books has appeared, each to do with animal populations but having little else in common (Andrewartha and Birch 1954; Lack 1954, 1966; Wynne-Edwards 1962; Elton 1966). A layman reading these would be quite justified in concluding that "There appear to be no rules". Indeed. this phrase seems to reflect Elton's attitude: "The whole field of population control in nature and theories about how it works has got into a rather peculiar state where a number of strongly held views exist that are at first sight incompatible with one another. . . . For, if one fact is certain, it is that somewhere at some time in some species everyone of these processes will be found acting as the chief or only limit to numbers. Similarly, somewhere at some time in some species, almost every conceivable combination of these factors will be operating in complex interaction" (Elton 1966, pp. 380-1).
I believe this is an over-tolerant attitude to adopt towards the two contrasting views on the evolution of reproductive rates, which is, after all, part and parcel of population control.