Arboreality has allowed for the evolution of increased longevity in mammals

Area of Science:

• Evolutionary Biology
• Gerontology
• Mammalogy

Background:

• The evolutionary theory of aging posits that reduced extrinsic mortality leads to delayed senescence and increased longevity.
• Flight in birds and bats is linked to lower extrinsic mortality and greater longevity compared to nonvolant mammals.
• Arboreality has been hypothesized to similarly reduce extrinsic mortality and increase longevity, as suggested by primate lifespans, but this remains untested in mammals broadly.

Purpose of the Study:

• To investigate whether arboreal mammals exhibit greater longevity than terrestrial mammals.
• To test the hypothesis that arboreality, like flight, confers survival advantages that delay aging.

Main Methods:

• Analysis of a comprehensive dataset of mammalian longevity records.
• Comparative analysis of lifespan between arboreal and terrestrial mammals, controlling for body size and phylogeny.
• Subclade analyses to examine the trend across different mammalian evolutionary groups.

Main Results:

• Arboreal mammals demonstrate significantly greater longevities than terrestrial mammals when controlling for body size, independent of phylogenetic relationships.
• This trend was observed across most mammalian subgroups, with notable exceptions in metatherians and euarchontans.
• In most clades, terrestriality is the ancestral state, and transitions to arboreality are associated with increased longevity, often evolving independently in multiple lineages.

Conclusions:

• The findings support the evolutionary theory of aging by demonstrating that an arboreal lifestyle is associated with increased longevity in mammals.
• Adopting an arboreal niche appears to reduce extrinsic mortality, thereby delaying senescence and extending lifespan.
• This study provides strong evidence for the role of lifestyle in shaping aging processes and longevity across the mammalian class.