Basic Strategies and Mechanisms of Enzyme Adaptation to Temperature

Abstract

Since the advent of evolutionary theory, environmental adaptations have been charted at many levels — at physiological, anatomical, and behavioural levels — of biological organization. Less well understood are “biochemical adaptations” to the environment. In part, this lack of information is an historic outcome of the development of adjacent fields of science and of an appropriate technology. But a more important reason for the hiatus in this field stems from the nature of the subject itself: biochemical adaptations usually are not apparent macroscopically, hence the biologist may be aware neither of their existence, nor of their mechanism. To illustrate what I mean, consider the apparent macroscopic attributes of two hypothetical species of fish — one, a surface species, living at the top of the water column at high temperatures and low pressures; the second, an abyssal species, living at low temperatures and high pressures. In much of their anatomy, physiology, and even behaviour the two species may be much alike. Both display comparable hydrodynamic properties and hence comparable swimming velocities; both display comparable growth, comparable osmoregulatory abilities and so forth. Above the biochemical level we may find little reason to regard one species as, say barophilic and stenothermic, and the other as barophobic and eurythermic.