Is it possible to slow the rate of ageing, or do biological constraints limit its plasticity? We test the ‘invariant rate of ageing’ hypothesis, which posits that the rate of ageing is relatively fixed within species, with a collection of 39 human and nonhuman primate datasets across seven genera. We first recapitulate, in nonhuman primates, the highly regular relationship between life expectancy and lifespan equality seen in humans. We next demonstrate that variation in the rate of ageing within genera is orders of magnitude smaller than variation in pre-adult and age-independent mortality. Finally, we demonstrate that changes in the rate of ageing, but not other mortality parameters, produce striking, species-atypical changes in mortality patterns. Our results support the invariant rate of ageing hypothesis, implying biological constraints on how much the human rate of ageing can be slowed.
Bibliographical noteFunding Information:
The governments of Botswana, Brazil, Costa Rica, Côte d’Ivoire, Kenya, Madagascar, Uganda, Republic of Congo, Rwanda and Tanzania provided permission for the primate field studies; all research complied with guidelines in the host countries. We thank the zoo and aquarium staff for manageing their animal records in Zoological Information Management System (ZIMS) and providing high quality demographic data for this project (Data Use Approval Number 82421). Duke University, Max Planck Institute of Demographic Research, and University of Southern Denmark provided logistical support. Annette Baudisch provided valuable feedback on the manuscript. This work was supported by NIA P01AG031719 to J.W.V. and S.C.A., with additional support provided by the Max Planck Institute of Demographic Research and the Duke University Population Research Institute.
© 2021, The Author(s).