DNA Repair and the Evolution of Longevity: A Critical Analysis

Comparative gerontologists argue that variation among species in DNA repair rates may explain differences in maximum lifespan, and support this claim with the observation that DNA repair rates and lifespan correlate positively among mammals. However, these findings may be confounded by both size and phylogeny. Repair rates and lifespan may be positively correlated because both are positively correlated with body size. In addition, previous comparative studies have not controlled for the potentially confounding effects of phylogeny. In this study, I elucidate why we might expect larger species to have higher DNA repair rates, independent of differences in lifespan, and use existing data to test whether the relationship between DNA repair rates and lifespan holds up after controlling for the potentially confounding effects of size and phylogeny. Reanalysis of the existing data suggests that there is little comparative evidence in favour of the hypothesis relating DNA repair rates and lifespan.