Interindividual variability

Albert F. Bennett

Two principal analytical approaches have been used in studies of organismal physiology. These are represented by the terms ‘comparative physiology’ and ‘physiological ecology’. The former compares functional characters in two or more populations, species, or higher taxa in an attempt to understand mechanism. Biological diversity is used to help understand principles of physiological design. Often the experimental species are chosen specifically because their systems demonstrate an extreme phenomenon or because the experimental preparation is technically accessible. The selection of a species on these grounds is known as the Krogh Principle […], which has been very influential and successful in guiding studies in comparative physiology for more than fifty years.

The second approach, physiological ecology or ecological physiology, examines the physiological attributes of a species and interprets them in the context of the natural environment or ecological niche of an animal. These studies concentrate on analysis of adaptive pattern, of how physiology, morphology, and behavior interact to permit survival and reproduction in a given environment. In this approach, emphasis is placed on ecological and evolutionary aspects of physiological functions. Monitoring the organism in its natural environment and speculation on selective factors that influenced the evolution of characters are the principal interpretive contexts of these studies.

Fonte: Bennett, A. F. 1987. In: Feder, M. E. & mais 3, eds. New directions in ecological physiology. Cambridge, CUP.