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 present a study of aging rates and longevity
across wild tetrapod ectotherms, utilizing data from 107 populations (77
species) of non-avian reptiles and amphibians. We test hypotheses of how
thermoregulatory mode, temperature, protective phenotypes, and pace of
life history contribute to demographic aging. Controlling for phylogeny
and body size, ectotherms display a higher diversity of aging rates than
endotherms and include phylogenetically widespread evidence of negligible
aging. Protective phenotypes and life-history strategies further explain
macroevolutionary patterns of aging. By adding ectothermic tetrapods, our
comparative analyses enhance our understanding of the evolution of aging.