Physiological Adaptation

Abstract

Abstract This contribution is concerned with the changes which occur in the individual human organism when it experiences new environments. Many of these changes, though by no means all, facilitate living in the new environment and are recognized as components of’individual adaptability’. Much of the ecological success of the human species is attributed to this adaptability, which is exceptional among animals and has played a major role in allowing our species to occupy every kind of environment on Earth. The unique features of human adaptability lie in behaviour, which of course is also at the root of technology. But it also appears that human beings are outstandingly adaptable in other physiological systems, and it is these to which attention will be given here. Although ‘individual adaptability’ is a species characteristic, i.e. all individuals possess the capacity, the degree and effectiveness of that capacity may vary from person to person. Some of this variation is probably genetically determined—indeed it needs to have been in the past to have evolved, by natural selection, as a species characteristic—but it is usually taken that when two individuals differ in the state of a physiological system affecting adaptability it is because they are in, or have in the past experienced, different environments.