Aging and changes in genetic information.

Abstract

Although all placental mammals are characterized by similar morphological, physiological, and biochemical parameters, they differ from one another in maximum achievable life span by approximately fifty-fold (1,2). Even within closely associated families of recent evolutionary occurrence, such as the primates and Myomorph rodents, e.g., Mus musculus and Peromyscus leucopus, life spans vary by more than twenty fold (3) and three fold (4), respectively. Thus, it appears that whatever governs the life span of a species must be able to be modified rapidly. This imposes strong constraints on the possible genetic mechanisms for the evolution of longevity-assurance systems (4). Two ways by which rapid evolution of longevity could occur, and yet be consistent with basic molecular genetics, would be either via modification of already existing genetic information (species differences in longevity reflecting differences in the turning off of longevity-assurance systems during fetal development), or through slight but significant changes in a number of interlocking processes governing phenotypic expression. Either or both of these mechanisms might explain the rapid evolution of life span within species without necessitating the concurrent input of new genes.KeywordsPolycyclic Aromatic HydrocarbonLife SpanExcision RepairXeroderma PigmentosumPyrimidine DimerThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.