Humans and animals are structurally designed as a compromise to guarantee optimal survival until the time of reproduction based on natural selection that is effective until that age. Modern conditions of life including improvement of hygiene, preventive and curative medicine as well as socio-economic and political developments have led to an increase of the mean life expectancy that allows ever larger proportions of the population to reach an age that is far beyond that of the reproductive phase. The concept of a Darwinian-evolutionary basis for the development of age-related diseases in principle postulates that genetic traits that are beneficial in younger years to allow for successful reproduction may become deleterious in the elderly, i.e. when selective pressure does not seem to be effective anymore. Examples for this mechanism of pleiotropic antagonism taken from the work of the Institute for Biomedical Aging Research in Innsbruck, Austria, include atherosclerosis, benign and malignant prostate hypertrophy, Alzheimer's disease and the reciprocal relationship between cellular senescence and cancer.