Archive | 2021
The influence of phylogeny and life history on telomere lengths and telomere rate of change among bird species: a meta-analysis
Abstract
Longevity is highly variable among animal species, and has coevolved\nwith other of life-history traits, like body size and rates of\nreproduction. Telomeres, through their erosion over time, are one of the\ncell mechanisms that produce senescence at the cell level, and might\neven have an influence on the rate of ageing in whole organisms.\nHowever, uneroded telomeres are also risk factors of cell\nimmortalization. The associations of telomere lengths, their rate of\nchange, and life-history traits independent of body size are largely\nunderexplored for birds. To test associations of life-history traits and\ntelomere dynamics, we conducted a phylogenetic meta-analysis using\nstudies of 53 species of birds. We restricted analyses to studies that\napplied the telomere restriction fragment length (TRF) method, and\nexamined relationships between mean telomere length at the chick (Chick\nTL) and adult (Adult TL) stages, the mean rate of change in telomere\nlength during life (TROC), and life-history traits. We examined 3\nprincipal components of 12 life-history variables that represented: body\nsize (PC1), the slow-fast continuum of pace-of-life (PC2) and\npost-fledging parental care (PC3). Phylogeny had at best a\nsmall-to-medium influence on Adult and Chick TL (r² = 0.190 and 0.138,\nrespectively), but a substantial influence on TROC (r² = 0.688).\nPhylogeny strongly influenced life histories: PC1 (r² = 0.828), PC2\n(0.838), and PC3 (0.613). Adult TL and Chick TL were poorly associated\nwith the life-history variables. TROC, however, was negatively and\nmoderate-to-strongly associated with PC2 (unadjusted r = -0.340; with\nphylogenetic correction, r = -0.490). Independent of body size,\nlong-lived species with smaller clutches and slower embryonic rate of\ngrowth may exhibited less change in telomere length over their\nlifetimes. We suggest that telomere lengths may have diverged even among\nclosely avian related species, yet telomere dynamics are strongly linked\nto the pace of life.