Data from: Decades of field data reveal that turtles senesce in the wild

Lifespan and aging rates vary considerably across taxa; thus,
understanding the factors that lead to this variation is a primary goal in
biology and has ramifications for understanding constraints and
flexibility in human aging. Theory predicts that senescence—declining
reproduction and increasing mortality with advancing age—evolves when
selection against harmful mutations is weaker at old ages relative to
young ages or when selection favors pleiotropic alleles with beneficial
effects early in life despite late-life costs. However, in many long-lived
ectotherms, selection is expected to remain strong at old ages because
reproductive output typically increases with age, which may lead to the
evolution of slow or even negligible senescence. We show that, contrary to
current thinking, both reproduction and survival decline with adult age in
the painted turtle, Chrysemys picta, based on data spanning >20 y
from a wild population. Older females, despite relatively high
reproductive output, produced eggs with reduced hatching success.
Additionally, age-specific mark–recapture analyses revealed increasing
mortality with advancing adult age. These findings of reproductive and
mortality senescence challenge the contention that chelonians do not age
and more generally provide evidence of reduced fitness at old ages in
nonmammalian species that exhibit long chronological lifespans.