Whittemore, K. et al. Proc. Natl Acad. Sci. USA 116, 15122–15127 (2019)

Although previous studies suggest that telomeres are involved in aging, no correlation has been found between the lifespan of a species and initial telomere length. Humans for example have shorter telomeres than mice (5–15 kb versus 50 kb) but have much longer lifespans. A new study used high-throughput quantitative fluorescence in situ hybridization (HT Q-FISH) to measure at different ages telomere length in peripheral blood mononuclear cells from individuals of different species of birds and mammals (including mouse, goat, American flamingo, and Sumatran elephant), and calculate telomere shortening rate for each species. The results show that telomere shortening rate, but not initial telomere length, is a powerful predictor of species lifespan.