FIG. 1.

The role of genes in aging-related traits: Deterministic and dynamic concepts. Currently prevailing strategies traditionally consider genetic susceptibility to aging-related traits in framework of a concept of heritability. This concept assumes that a phenotype (P) can be represented as an additive superposition of genetic (G) and environmental (E) effects (A). Linkage of genes to a phenotype within this concept is implicitly assumed to be of deterministic nature. This concept, however, was developed for reproduction-related phenotypes used in breeding experiments with plants and referred to “the genetic contribution to variance within a population and in a specific environment.” ¹¹² Extension of this concept to aging-related human traits is, therefore, at best problematic because of: (1) Lack of directly programmed deterministic mechanisms linking genes with those traits and (2) uncontrolled changes in environmental exposures for humans. Given these constraints, B illustrates the dynamic concept when the effects of genes on aging-related traits have to be inevitably shaped by aging-related processes (senescence) in dynamic environment. The role of environment in this concept is through activation of genes at different periods of life and modulation of gene actions over the life course and across generations. Color images available online at www.liebertpub.com/rej