The analysis of the blood of a woman who died at the age of 115, hints that our lifespan might ultimately be limited by the capacity for stem cells to keep replenishing tissues day in day out:
"In van Andel-Schipper's case, it seemed that in the twilight of her life, about two-thirds of the white blood cells remaining in her body at death originated from just two stem cells, implying that most or all of the blood stem cells she started life with had already burned out and died."
"The other evidence for the stem cell fatigue came from observations that van Andel-Schipper's white blood cells had drastically worn-down telomeres – the protective tips on chromosomes that burn down like wicks each time a cell divides. On average, the telomeres on the white blood cells were 17 times shorter than those on brain cells, which hardly replicate at all throughout life."
We know better than most, how essential the generation of healthy blood cells is to a healthy life...
Photo shows a Royal Spoonbill taken during the mating season. That glorious plume sadly disappears when the mating season is over.