Evolution of human longevity: a critical overview.

Evolution of longevity of the ungulates, carnivores and primates is reviewed. Special emphasis is focused on recent evolutionary history of longevity along the hominid ancestral-descendant sequence leading to modern man. Maximum life span potential (MLP) or the change in MLP is predicted in extinct species by (1) a phylogenetic analysis of the MLP of present living species and (2) an empirical equation using brain and body weight estimates from fossils. Both of these methods indicate MLP generally increased during mammalian evolution and at an extremely fast rate during the appearance of the hominid species. These results suggest that relatively few genetic alterations were necessary during the recent evolutionary history of man to significantly extend his innate ability to maintain mental and physical health. Much evidence indicates these genetic alterations principally involve regulatory genes, which control a conserved set of structural genes. Evolution of longevity in man could therefore be a result of simple changes in temporal and quantitative expression. Whether these genetic alterations result from mutational changes and/or chromosomal rearrangement cannot yet be evaluated.