The evolutionary theory of senescence can be stated as follows: while bodies are not designed to fail, neither are they designed for extended operation.
Sentiment: NEGATIVE
We've spent the last few millennia aware that senescence is horrible but knowing nevertheless that it's inevitable. We've had to find some mechanism to put it out of our minds so we can get on with our miserably short lives.
To sustain longevity, you have to evolve.
Perhaps genes did regulate the aging process. Perhaps different organisms had different life spans because a universal regulatory 'clock' was set to run at different speeds in different species.
Human lifespan used to be 30 years, 25 years. But there's no basic, fundamental reason why it has to be short.
In specific circumstances the period of aging decline can set in earlier in a particular organ than in the organism as a whole which, in a certain general or theoretical sense, is left a cripple or invalid.
Aging is mostly the failure to repair.
Imagine that: If you could change one of the genes in an experiment, an aging gene, maybe you could slow down aging and extend lifespan.
Immunity to obsolescence is the only obsolescent-immune conceit of the past millennium.
We know that people who are born with shorter telomeres than normal also have a shorter lifespan. We know that shorter telomeres can cause a shorter lifespan.
The general rule is that anything that is passed on in reproduction does not undergo senescence.