Two aspects of longevity are associated with the rate of loss of
telomeres in birds
Abstract
Telomeres, the terminal repetitive DNA sequences at the ends of linear
chromosomes, have strong associations with longevity in some major taxa.
Longevity has been linked to rate of decline in telomere length in birds
and mammals, and absolute telomere length seems to be associated with
body mass in mammals. Using a phylogenetic comparative method and 30
species of birds, we examined longevity (reflected by maximum lifespan),
absolute telomere length, the rate of change in telomere length (TROC),
and body mass (often strongly associated with longevity) to ascertain
their degree of association. We divided lifespan into two life-history
components, one reflected by body size (measured as body mass), and a
component that was statistically independent of body mass. While both
lifespan and body mass were strongly associated with a family tree of
the species (viz., the phylogeny of the species), telomere measures were
not. Telomere length was not significantly associated with longevity or
body mass, or our measure of mass-independent lifespan. TROC, however,
was strongly associated with mass-independent lifespan, but to a lesser
degree with body mass. Our results supported an association of TROC and
longevity, in particular longevity that was independent of body size and
part of the pace-of-life syndrome of life histories.