A Biodemographic Interpretation of Life Span



The life span of individuals and the life expectancy of the populations they comprise have always been topics of interest to scientists and the lay population. In modern times, forecasts of life span and life expectancy have become particularly important public policy issues because of their influence on the future solvency of age-entitlement programs. The authors present a brief discussion of the origin of the notion of life span, discuss its relevance and importance in light of recent developments in the emerging field of the biodemography of aging, and explore the theoretical and biological forces that influence the duration of life of sexually reproducing species.