New Data Supports Mutation Accumulation Theory of Aging

A recent study has yielded data supporting the mutation accumulation (MA) theory of aging, a theory that attributes the aging process to the accumulation of mutations of genes that are kept in check by reproductive-oriented selection processes early in life and only are active later on. The study appeared October 17, 2002, in the online edition of the Proceedings of the National Academy of Sciences.

Researchers from the University of Illinois (Urbana-Champaign, USA) used mathematical models to evaluate the reproductive success of 100 different genotypes of Drosophila across various age groups. They found that the deleterious effects of mutations on reproduction rose dramatically with age during the reproductive years in both homozygous and heterozygous genotypes. Reproductive success declined more rapidly, however, in the homozygous lines, as predicted by the MA theory.

"This study allowed us to detect certain kinds of genetic effects called dominance variance that are predicted to increase with age only under the MA theory,” explained first author, Dr. Kimberly Hughes. "The power to detect these effects is critical to tests of evolutionary aging theories, because an age-related increase appears to be a unique prediction of the MA theory, while other kinds of genetic effects can increase under either model. The results suggest that more needs to be learned about which genes do what and when in the aging process so that artificial manipulation does not cause evolutionary damage in future generations.”




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Univ. of Illinois at Urbana-Champaign