Instructions for authors
Please provide a short abstract of 100 to 250 words. The abstract should not contain any undefined abbreviations or unspecified references.
Genes and Aging
Genes may be regarded in at least two quite distinct ways in relation to processes of aging. They are units of genetic transmission from parent to offspring and, also, intracellular agents whose products interact with environmental forces to control development, differentiation, metabolism, and degeneration. Much of this chapter will deal with the results of genetic transmission, that is, with genetic similarities and differences between individuals, present throughout their life-spans. I will attempt to demonstrate that the patterns of the aging of individuals carrying an identical array of genes will show greater similarity than will the patterns of the aging of individuals carrying different assortments of genes. To do this, I will have to deal mostly with genetically controlled animals, and I will try to bring home to you why and how these animals with specific genotypes have become important in research on the biology of aging.
Evolution of human longevity and the genetic complexity governing aging rate.
Genetic complexity of processes governing the aging rate of man was estimated by determining the maximum rate lifespan has evolved along the hominid ancestral-descendant sequence. Maximum lifespan potential was found to have increased approximately 2-fold over the past 3 million years, reaching a maximum rate of increase of 14 years per 100,000 years about 100,000 years ago. It is estimated that about 0.6% of the total functional genes have received substitutions leading to one or more adaptive amino acid changes during this 100,000-year time-period. This suggests that aging is not the result of an expression of a large number of independently acting processes. Instead, primary aging processes appear to exist where only a few genetic changes are necessary to decrease uniformly the aging rate of many different physiological functions.