Numerous empiric data prove incontestably that species-specific lifespan is under control of genetic program. At the same time the modern evolution theories of aging deny an opportunity of existence of specific genes predetermining longevity. Basic premise for non-acceptance of the aging gene concept is convincing: animals in habitat do not live long enough for aging to exert any effect on their survival. Therefore, the natural selection can not differentiate them by the longevity attribute. To solve the collision the population approach was used in this work. As known from ecological laws the innate population growth rate (r(in)), lifetime of one generation (T), and inborn fertility (R(0)) are interconnected by the next dependence: r(in) = In R(0)/T. The examining of mathematical model of population showed that r(in) value is stabilized by inter-population natural selection on the level which corresponds to environment press in the species ecological niche. Therefore, species-specific longevity and fecundity are under control of this natural selection.