
SAGE KE Bulletin BoardPrevious Message  Return to Topics  Next Message Abstract as an additional information11 January 2002 Leonid Gavrilov Dear Colleagues, Here is the abstract of this new article for discussion: The reliability theory of aging and longevity. Gavrilov LA, Gavrilova NS. Center on Aging, NORC/University of Chicago, 1155 East 60th Street, Chicago, IL, 60637, U.S.A. Reliability theory is a general theory about systems failure. It allows researchers to predict the agerelated failure kinetics for a system of given architecture (reliability structure) and given reliability of its components. Reliability theory predicts that even those systems that are entirely composed of nonaging elements (with a constant failure rate) 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 latelife mortality deceleration with subsequent levelingoff, as well as the latelife mortality plateaus, 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) in newly formed systems. It also explains why organisms "prefer" to die according to the Gompertz law, while technical devices usually fail according to the Weibull (power) law. Theoretical conditions are specified when organisms die according to the Weibull law: organisms should be relatively free of initial flaws and defects. The theory makes it possible to find a general failure law applicable to all adult and extreme old ages, where the Gompertz and the Weibull laws are just special cases of this more general failure law. The theory 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. Overall, reliability theory has an amazing predictive and explanatory power with a few, very general and realistic assumptions. Therefore, reliability theory seems to be a promising approach for developing a comprehensive theory of aging and longevity integrating mathematical methods with specific biological knowledge. 
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