This book examines the concept of adaptation in four major fields in the human sciences. Genetic aspects are first considered through an examination of the human genes which have so far been identified as conferring survival value in particular environmental circumstances. The drift versus selection argument is also fully reviewed. The second contribution concerns the physiological changes which occur when individuals move from one environment to another. In the past, most attention has been given to the mechanisms of these changes, but here the focus is on the effects. The third...