Ricerc@Sapienza

One of the oldest but still debated question in
evolutionary demography is about the shape of
the mortality trajectory for humans at extreme
ages. Several studies suggested that for humans
adult and early-old death rates rise exponentially
up to about age 80 and thereafter decelerate. Other
studies, however, found that the exponential
increase of the mortality risk with age continues
at advanced ages in humans. Recent studies on
exceptionally long-lived individuals have shown
that the trajectory of mortality levels off at
extreme ages. This is consistent with the theory
of the selective survival in heterogeneous
populations. However, other evolutionary explanations
are possible.