How does the somatic mutation theory explain aging?

The somatic mutation theory of aging posits that the aging process is driven by the gradual accumulation of mutations within the DNA of somatic (body) cells.12

According to this theory, these genetic "errors" disrupt the normal function of cells. Because DNA serves as the blueprint for the synthesis of vital proteins and enzymes, damage to these molecules can lead to the production of incorrect or nonfunctional proteins, ultimately resulting in cellular malfunction or death. Over time, as these mutated cells accumulate and fail to perform their biological roles, the organism experiences the decline associated with senescence.12

The theory emphasizes the importance of DNA repair mechanisms, which work to correct genetic damage. The rate of aging may be governed by the efficiency of these repair systems rather than just the frequency of damage itself. However, the theory faces scientific scrutiny; for instance, experiments with certain insects have shown that haploid organisms, which lack a second set of chromosomes to compensate for mutations, do not necessarily have shorter life spans than their diploid counterparts, suggesting that somatic mutations may not be the sole factor in aging.2