With animals exhibiting advanced characteristics, understanding aging gets abstruse.
In some animals, a high correlation was found between lifespan and rate of telomere deterioration, essentially from observation that the possible limit of cell divisions are limited by telomeres.
So far, the mystery of aging is somewhat a longways before being fully cracked.
Another variable as crucial in the aging process as telomere deterioration when DNA replicates, are mitochondrial DNA mutation and dysfunction over time from the process of making energy (redox reactions), in some cases at a rate faster than DNA.
Some studies have also found genes related to aging.
Alter all such mechanisms (and possibly more to discover with further research) and there is some hope in the prospect of avoiding death a little longer.
How dismal that evolution limited an organism's clock with a deluge of mechanisms at cellular and molecular level. I suppose nature being a ruthless boss, we have our work cut out for us.There is senescence for you.