It's very likely that aging is driven by some kind of scheduled gene program. It makes perfect sense to phase out individuals from a group-level selection point of view.
By this logic, as a hedge against sudden death around ~50, the human body start cranking down the output of its diverse subsystems by then, to maximize operacional life, just like NASA engineers from time to time turn off instruments in the voyager to keep it operational against the odds. This is what we call ageing.
What limitation is our body pushing off by 'choosing' to age, instead of continuing as normal?
Edit: Regardless of the validity of the argument, I loved that comic, thanks for sharing.
So the question becomes why can't somatic cells repair themselves to be as healthy as germline cells?
https://en.wikipedia.org/wiki/List_of_tallest_people
And another was 76cm high:
But that's just guessing. The article might not even have found something profound, but a life-style effect. On the one hand, we're living long (historically speaking), on the other hand, we have unnatural habits.
It's the same as how although you can occasionally get a "natural" person over seven feet tall, it's very rare. Most really tall people have gigantism or some other form of pituitary abnormality, and I believe every recorded person to break eight feet has had such an abnormality.
It's like asking why we've never had someone with 500 IQ. There's a hard limit where anyone with enough of a mutation to enable that would probably also not survive long at all. And indeed with the height thing we see a lot of super-tall people dying younger due to cardiovascular strain and other issues. You get the picture.
The "patterns of aging" you describe are, again, definitionally just what happens when the same organs built and functioning the same way across species undergo their respective failure modes. It makes more sense for all skins to exhibit the same signs of aging if they're all just wearing out the way "skin" does, rather than being attacked by species-specific "age limiter" processes artificially enforcing lifespan limits. Why would something like skin even need to decay at all, when it's basically unrelated to aging-related death?
Imagine the "aging program" bugs out 1 in 100 times, a pretty high failure rate. However, imagine the program runs in 10 systems in the body, and success in any one of these systems is enough to age and kill you. The body is quite fragile after all.
If this were the case, then in order to not age at all, a person would need not just a 1/100 event to occur, but a (1/100)^10 event to occur. That's 1 in 100,000,000,000,000,000,000. In other words, one in a hundred quintillion.
A hundred quintillion is about 840 million times higher than the number of humans who have ever lived, which is 120 billion.
There's extensive scientific research on the subject of aging if you care to sink time into reading about it.
Consider one of the many examples of embedded systems that suffered from subtle bugs that were dependent on environmental factors after they were left running for too long. The official manufacturer provided solution was to reboot (ie there is no solution). Now imagine someone in a comment section somewhere proposes the idea that these bugs are actually intentional program features. That's the scientific level this discussion is at.
Which is actually a pretty good reason for something like menopause to get programmed in. A proto-human capable of getting pregnant into her 60s would produce more offspring, but if accumulated damage meant they (and she) rarely survived the pregnancy, that could be less beneficial to the family group (including numerous relatives other than direct descendants) on average than having her switch the capability off and live another generation (but not many more generations, because then there's a lot of infertile people competing for food, and your tribe only needs so much accumulated wisdom)
So, to rejuvenate the body, you would have to find where the current state of that program is stored, and overwrite it to a younger one, as if using a debugger. So far there are two promising developments about that: Michael Levin's research about bioelectricity, and Harold Katcher's research about exosomes (he seems to have abandoned it, but other people are picking up).
> Back in 1994 a study looked at every man entered into the Oxford Classical Dictionary who lived in ancient Greece or Rome. Their ages of death were compared to men listed in the more recent Chambers Biographical Dictionary. Of 397 ancients in total, 99 died violently by murder, suicide or in battle. Of the remaining 298, those born before 100BC lived to a median age of 72 years. Those born after 100BC lived to a median age of 66. (The authors speculate that the prevalence of dangerous lead plumbing may have led to this apparent shortening of life).
https://www.bbc.com/future/article/20181002-how-long-did-anc...
Just one source