An absolute metabolic scope for activity

The basic concept, discussed and reviewed, is that an organism of set mass has a set total metabolism and the rate at which utilisation of this total metabolism proceeds determines the individual time scale of an organism. To demonstrate this postulate the allometric relationships that exist between metabolic rate and mass are reviewed and expanded to include their relations to longevity. A finite total metabolism is seen as an absolute metabolic scope for activity and is discussed in relation to: the basal metabolic rate and its own capacity or scope for change; conditions of changing mass, growth: the timing of events other than death, with examples from such fields as development, population biology, human perception, and physiology. In the latter example particular regard is paid to the differences between ectothermal and endothermal organisms and their internal regulative capacity. It is concluded that the concept of an absolute metabolic scope is important in that it defines biokinetic limits.