[Is selection for extended life expectancy possible by regularity in aging?]

To answer this question it is important to explain the mode of development of the different maximum life span potentials (MLP) during evolution. We know by empiric-historical investigations, that at least later in evolution appearing species of mammals possess a higher MLP. What does then mean a "regular process"? The aging process is a regular one, being a physiologic event, in the character of that what all we can determine at it, as far as it allows explanation and prediction. This did succeed in a high degree during the until now short tradition of experimental gerontology. We refer to experimental results not only from the literature but also from our own work on repair, genetic and metabolic changes and multivariate investigations into the biological age, to decide from two hypotheses of the causes of aging, how the title question can be answered: a) aging as a programmed event, brought about by aging genes, controlled by an intrinsic clock. These genes should restrict life expectancy or the replicative capacity of cells--hence the adaptive hypothesis; b) aging as a consequence of the accumulation of errors counteracted by antibiosenescent strategies (AS)--hence nonadaptive hypotheses, the most plausible one being that of the disposable soma. Later species are adapted better to changing environmental conditions by their other development, their ecological niches are larger, their environment contains specifically lesser dangers and risks, because they better cope with them--therefore it is worth while to spend more energy for the maintenance of their soma than for their reproduction: they develop better and more AS.(ABSTRACT TRUNCATED AT 250 WORDS)