alt Hacker NewsThese papers simply present the accumulated damage hypothesis with new window dressing. They do not account for the known facts.
The article about these papers does not present a mechanism that would account for the Hayflick Limit.
Nor does it explain why dogs, for example, age and die more quickly than humans. If there is a mechanism of epigenetic drift that would explain this, I do not see it in the article.
The obvious answer to senescence is that we are programmed to do it. Cells die when they are supposed to die; if they don't, we have a problem.
Likewise, mammals die when they are supposed to. It takes less time to train a puppy to survive on its own than it takes to train a human. Hence, dogs are optimized to age and die more quickly. It's better for the species.
If we were not programmed to get old and die, evolution through natural selection would not work. We would never adapt to changing environments and our species would fail.
Aging and death is not an accident or a deterioration from damage or a drift away from a correct instruction set. It is an absolute hard necessity, without which we would all be long gone.
Stop wasting your time on nonsense articles like this and seek the mechanism that provides us as a species with the flexibility to adapt. Until we see aging and death as an core mechanism, we're going to be looking in the wrong place.
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This comment is nonesense.
Stop spewing this claptrap as copium for your own mortality. Everything is natural and «part of life» till it isnt, like cervix cancer was like syphilis was like rheumatic fever was.
You die because your DNA gets damaged and your cells lose the ability to repair themselves.
You werent «programmed» to get alzheimer cancer artherosclerosis dementia and embolism. It’s not supposed to happen.
gtfooh
A lot of fallacies and assumptions in this comment. First of all there is nothing in biology or evolution where the "good of the species" has any kind of bearing on natural selection. This is the group selection hypothesis that has numerous counterexamples. If anything selection happens at the gene level over the long run.
There is also no clear reason we know of yet as to why a human being couldn't simply reach sexual maturity and hunting age faster. In fact, there might be at least some evidence other hominids did reach sexual maturity faster. It is not fully understood why humans take so long, but in animal kingdom terms we take roughly as long as the Asian Elephant to reach reproductive maturity. Almost certainly a tradeoff for achieving greater brain development and intelligence, but this could also simply be the consequences of being intelligent (e.g. it's easier to evolve for bigger skulls once ape intelligence surpasses a threshold where the apes are capable of committing to greater early childcare such that natural selection in absence of intelligence is weakened).
If dogs were optimized to age and die more quickly for the betterment of the canine species, then you could make the same argument for humanity. That's simply not what's going on. Human ancestors in the past who traded generation time for greater intelligence, likely selfishly outcompeted those who did not, and those other hominids either died off or represent a much smaller allelic contribution to the extant human gene pool.
For evolutionary biologists, aging and death similarly likely represent evolutionary tradeoffs. After reaching sexual maturity, as the probability of producing more offspring declines, so too does natural selection as alluded to in the article. Women are born with their entire compliment of ova and the rate of errors increases dramatically as they get older. Men have similar but more subtle issues with sperm generation. These error rate absolutely can be driven by mechanical stresses over time, and I would imagine could be driving much of the selective pressure that puts a cap on human longevity in the long run.