Radiatsionnaia Biologiia, Radioecologiia / Rossi?skaia Akademiia Nauk
Experimental data obtained from studies on the objects with different organization were analyzed. These data expand the ideas about the phenomenon of "viability determinate decrease in offspring of irradiated cells" discovered in the 1970s. This phenomenon was evaluated according to the standpoint of modern radiobiology.
Maximum life span can be increased by dietary modulation in rodents to a degree well beyond what is seen in "normal" laboratory animals, and probably well beyond the "potential" that wildlife animals might achieve if predation could be eliminated. With a fairly high order of probability, the same might be obtained in humans. There is no reason to insist that maximum life span in humans is irretrievably fixed.
In most primate groups emigration of the maturing young of one or the other sex tends to serve as an incest avoidance mechanism. Among most primate species it is the males who change groups. This supports the theory that, in terms of reproductive success, males should compete for mates and females should compete for resources. In hominoids the combination of increased longevity and greater female discrimination in mate selection seems responsible for female emigration. This may relate to the high frequency of patrilocality and male control of resources among human groups.
Placing lifespan in the context of the life history of an organism, Alex Comfort's work has stimulated the analysis of dietary restriction (DR) and its effects on lifespan in an evolutionary context. DR results in the curtailment of energy-intensive nonfood-gathering activities, increased efficiency of food utilization, an increase in food acquisition activity, an increase in the reproductive lifespan, and an increase in the protection of genomic integrity.
The question of whether temporal equivalence can be established between test species and humans and be useful in the safety assessment of food additives has puzzled risk assessors throughout decades. The basic biological elements in any mammalian species, including humans, such as homeostasis, basal metabolism and body size/surface area, reproduction features, the timing of cellular proliferation, and aging and health as well as the relation between aging and the diet are essential in this discussion.
The evolutionary theory of ageing explains why ageing occurs, giving valuable insight into the mechanisms underlying the complex cellular and molecular changes that contribute to senescence. Such understanding also helps to clarify how the genome shapes the ageing process, thereby aiding the study of the genetic factors that influence longevity and age-associated diseases.
The disposable soma theory suggests that longevity is determined through the setting of longevity assurance mechanisms so as to provide an optimal compromise between investments in somatic maintenance (including stress resistance) and in reproduction. A corollary is that species with low extrinsic mortality are predicted to invest relatively more effort in maintenance, resulting in slower intrinsic ageing, than species with high extrinsic mortality.
When organisms as diverse as yeast and rodents are subjected to a restricted diet, they live longer. The good news is, according to Vaupel, Carey, and Christensen in their Perspective, that switching to a restricted diet at any age can yield the benefit of increased longevity--at least in flies (Mair et al.).