Biodemographic (Reliability) Theory of Aging and Longevity

Leonid A. Gavrilov, University of Chicago

The purpose of this study is to develop a comprehensive biodemographic theory of aging, using the systems approach (the reliability theory, see Gavrilov, Gavrilova, Journal of Theoretical Biology, 2001, 213). This theory predicts that even those systems that are entirely composed of non-aging elements will nevertheless deteriorate (fail more often) with age, if these systems are redundant in irreplaceable elements. Aging, therefore, is a direct consequence of systems redundancy. Reliability theory also predicts the late-life mortality deceleration as an inevitable consequence of redundancy exhaustion at extreme old ages. The theory explains why mortality rates increase exponentially with age (the Gompertz law) in many species, by taking into account the initial flaws (defects). The theory also explains why relative differences in mortality rates of compared populations (within a given species) vanish with age, and mortality convergence is observed due to the exhaustion of initial differences in redundancy levels.