During the last decade there has been a marked upsurge of interest in the topic of human ageing. This is largely due to the realization that the elderly comprise an ever-increasing proportion of the population and, at least in industrialised nations, age-related disorders now account for a substantial component of the expenditure on health care. In recent years, trends in ageing research have appeared to focus either at the cellular and sub-cellular levels or on specific topics in geriatric medicine. The aim of a two-day symposium held at Chelsea College, University of London, in April 1984, organised on behalf of the Society for the Study of Human Biology and the British Society for Research on Ageing, was to help bridge these two specialist areas by considering human ageing within the interdisciplinary context of human biology. In the proceedings presented in this book, the editors (also the organisers of the symposium) have brought together scientific papers presented by a group of distinguished research workers in gerontology and geriatrics. Although it obviously was not possible to achieve a fully comprehensive treatment of the subject, many of the underlying principles and current views on human senescence are considered, including stochastic and non-stochastic theories of ageing, biological markers in age assessment, and demographic, social and clinical features of ageing populations.

To biologists of whatever persuasion, it is evident that a phenomenon which is common to all species must be associated with, if not an integral part of, the evolutionary process. Accordingly, the initial chapter is concerned with a model to explain ageing in terms of energy investment and natural selection.