PHYSIOLOGICAL VARIATION IN ANIMALS

作者：C. Ladd Prosser · 发表于：Biological reviews/Biological reviews of the Cambridge Philosophical Society · 年份：1955 · DOI：10.1111/j.1469-185x.1955.tb01208.x · 被引用次数：225 · 研究领域：Physiological and biochemical adaptations、Fish Ecology and Management Studies、Environmental Toxicology and Ecotoxicology

SUMMARY Numerous examples are cited of physiological characters which, like morphological characters, vary genotypically, ontogenetically or phenotypically. Physiological variation is useful in describing interspecific relations, intraspecific variation and the limits of ecological range. Physiological variation of a character permits the establishment of populations at environmental limits and thus predisposes a race for genetic fixation of a character (Baldwin effect). Such variation is primary in providing one mechanism of reproductive isolation. Secondary physiological variation functions in habitat selection, particularly after reproductive isolation. Criteria for physiological variation are given by measurement of internal state in relation to environmental stress. In regulators a criterion is the point of failure of homeostatic mechanisms; in adjusters a criterion is the limit of tolerance after maximum acclimation. Both regulation and adjustment are adaptive to environmental change; in both types, phenotypic variation must be distinguished from genotypic variation. Examples of physiological variation in osmotic adaptation, in different populations of the same species, are given for species of Paramecium, Euplotes, Asterias, Gammarus, Callinectes, Anopheles, Onchorhynchus and Gasterosteus. Genetically different races have been established for Gasterosteus aculeatus and Euplotes vassus. Ionic balance has been little studied as a basis for variation of populations but sp...