Telomere Dynamics with Age are Very Different Between Mammalian Species

Telomeres are caps of repeated DNA sequences at the ends of chromosomes. They shorten with each cell division, a part of the mechanism that ensures somatic cells can only replicate a limited number of times. Telomerase acts to lengthen telomeres, and in humans telomerase is only active in stem cells. Thus our cells exist in a two-tier system, in which only tiny populations of privileged stem cells are permitted unrestricted replication, while the vast majority of somatic cells are limited. Matters are similar across all higher animals, and this state of affairs likely evolved because it keeps cancer to a low enough level, and pushed off far enough into late life, for allow for evolutionary success. A lot of ink has been spilled on the topic

from http://besthealthnews.com/2019/07/telomere-dynamics-with-age-are-very-different-between-mammalian-species/

from
https://healthnews010.tumblr.com/post/186227761268