>>11602627you can just elongate your telomeres by activating hTERT constitutively or something. note that this actually wouldn't result in immortality, just longer telomeres. There is a possibility that it would have effects not well understood. It's also not that simple because there are telomere recognition factors (DNA BP's) which would have to be in complex with the telomere region. There are proteins such as Rap1 that are involved in "accounting" for TRF's as a measure of telomere length.
Cell senescence in general is controversial because there's scant direct evidence that it actually occurs in vivo (outside of tumor cells, where ~85-90% of tumors have active hTERT). Senescence is really something mainly observed in culture, but it's presumed to function in vivo because as differentiation progresses, proliferative ability decreases.
There's an argument that if senescence occurs in vivo, it's actually effective at lowering the chances of aggressive ancer appearing. Hundreds of cycles of divisions might be required for an aggressive tumor phenotype, but the theoretical limit of division (Hayflick limit) is typically 50-60 divisions. Much like other systems in biology, it's self-regulating and self-limiting on purpose, because there is a benefit.
Also, there is NO evolutionary benefit to longer lifespans/ functional immortality. Microbes are among the most successful organisms in history. Following that - simple eukaryotes, insects, etc. Complexity is not inherently advantageous, just as intelligence is not inherently advantageous. Are you so important, biologically, that you should get to live forever? Not really. Proliferative ability is generally the end goal in evolution. We consider ourselves to be in that "sweet spot" but actually biologically we are fairly awkward. Our large craniums add increased risk of pregnancy complications and necessitate a "premature" birth. Most mammals can walk within a few hours of birth, I have seen this in agriculture. Etc
