Diverse aging rates in ectothermic tetrapods provide insights for the evolution of aging and longevity

Comparative studies of mortality in the wild are necessary to understand the evolution of aging, yet ectothermic tetrapods are under-represented in this comparative landscape despite their suitability for testing evolutionary hypotheses. We provide the first comprehensive study of aging rates and longevity across tetrapod ectotherms in the wild, utilizing data from 107 populations across 77 species of reptiles and amphibians. We tested hypotheses of how thermoregulatory mode, environmental temperature, protective phenotypes, and pace of life contribute to aging. Controlling for phylogeny and body size, ectotherms displayed a higher diversity of aging rates than endotherms, and included many groups with negligible aging. Protective phenotypes and life-history tactics further explained macroevolutionary patterns of aging. By including ectothermic tetrapods, our comparative analyses enhance our understanding of aging evolution.