I doubt it.
IMO, aging is just a way to ensure that dying occurs.
And dying is necessary for evolution, as it's easier to replace the old with a new generation that understand better the reality than changing the current generation.
Old habits literally die hard.
I do wonder whether there is a point where the lost experience of other individuals weighs heavier than physically better adapted individuals. In a way, culture serves as a way to preserve information that would be lost by aging.
Another way to interpret this would be “increased diversity.” Which is a selection advantage in an environment that experiences change. While organisms don’t have “clocks” they do have different rates of aging, implying a biological control. And species that live longer tend to hold on to longer genomes. This tends to mean that short lived species hold diversity in their population while Long lived species hold diversity in every genome. Both operate as fitness advantages, and seem to imply that aging is a biological quality.
I know evolution doesn't work that way, but definitely sounds like an interesting thought.
> So that would be like killing a program and respawning a new process instead for some
> benefit like reclaiming memory or speed ...
>
> I know evolution doesn't work that way,
All species that didn't die of old age (if there were any) have disappeared regardless.
By your same logic, you could pick any species at all and call their traits "the winning strategy for long-term survival" as long as you live contemporaneously with them.
There are known species that don't seem to exhibit planned senescence--the naked mole rat is a commonly discussed example. Check the Wikipedia page for biological immortality[1] for more examples and info.
The article essentially claims that ageing is likely a result of interacting thermodynamic processes. If so, then without specific preventative measures, organisms will "age".
The discussion at this level is pretty hand-wavy. So without introducing more rigor, the best we can say is probably something like this: there hasn't been strong selective pressure in the past to develop anti-ageing strategies.
Though you won't see any of them developing rockets and space-stations. To what extent that is an evolutionary advantage on our part I'll leave to general consensus.
All species that used the Time Travel flatulence method have disappeared.
Emphasis is not exactly "can't", rather it is "has not yet"...
The research 100% disagrees with you.
Aging even occurs in computers: every computer will eventually get in an unexpected state that it cannot recover from. This could even be caused by a stray UV ray that flips a bit in an important memory sector.
Besides, if you look at all big society changes, you'll notice the old generation of people that lived before the change have a much harder time to accept / adapt to the new order while it's natural to the new generation.
That's not true. An previous generation might actually be better suited to a particular environment than the current generation.
Its main point is that ageing follows a roughly Gompertz-Makeham distribution, the statistics of which also nicely describe "wear-and-tear" processes like protein breaking.
The final paragraph even explicitly addresses the concerns you raise about possible routes to intervention in ageing processes.
Or evolution isn't interested in this outcome. It is probably benefitical for a species if members die once they get old, to make way for the new.
By saying "evolution isn't interested in this outcome" you're not so subtly anthropomorphizing evolution, but evolution does not have to have an "interest".
3 things are required for evolution to manifest
1. Variation
2. Heritability
3. Selection
Evolution has no "interest" in things that are "beneficial for a species". Evolution is an epiphenomenon of the existence of the three factors of variation, heritability, and selection. [0]
[0] https://www.ncbi.nlm.nih.gov/books/NBK22508/
EDIT: Just a comment that I didn't see one of my sibling replies whose first sentence I practically duplicated. Clearly at least two of us do not like anthropomorphizations of evolution.
If someone else reads higher order intentionality to it than that, why should that stop me from using a convenient turn of phrase? Sure, if someone wants to think that I’m implying my computer is sentient then they’re odd and incorrect but I’m not going to stop saying it. It’s convenient.
Species is a nebulous conflation of genetics, behavior and habitat. Some like to say that ability to bear fertile offspring is the limit to determine speciation. This definition allows ignoring the mule offspring of horses and donkeys, strengthening the position that the latter are different species, but fails on the liger, which can be fertile with few people claiming tigers and lions to be of the same species. So breeding is insufficient to determine species.
Species is then more a measure of the human perception of things being different than any more specific quality.
The idea that a species could somehow convince its constituent individuals to act for the benefit of the species isn't useful. Individual members of the species will each act with self-interest in the pursuit of resources, mates and territory. Altruistic behaviors will propagate by out-competing "cheating" behaviors, and most often multiple simultaneous behavior strategies will exist within a population. Even within an individual, which might choose different actions in different situations.
If there was more benefit to living longer in the species, cheaters would certainly exploit it in the face of "dying for the good of the species". However, if the detriments of living longer cause the individual to be unable to compete with shorter living individuals, the species will continue to tend to a shorter lifespan.
Suggesting that the creatures will conspire to die and make room for their offspring suggests that the anthropomorphized idea of species is causing faulty assumptions about the nature of the subject to be held, and that the metaphor should be discarded as detrimental to understanding.
I wasn't suggesting that, nor was anyone else. I really think you're reading too much into it. I'm merely suggesting, the rather obvious thought that you and everyone else here probably understands, that a group of animals where the weak and old die to make way for the new (obviously not in a self-sacrofice way, but just how the animals are) will probnably be more successful, on average, that a group of animals where the old very slowly, or indeed even never, die.
Now, I apologise that the use of language "evolution is not interested in this outcome" caused such confusion.
There doesn't need to exist some conspiracy in a species to explain death.
The new compete with the old for resources, mates and avoiding predators ( don't need to be faster than a bear, just faster than your friends ). The old have a lifetime of cellular damage, injuries, diseases etc having done damage to their bodies. These things make them more susceptible to predators and dying, being unable to mate do to body problems, being unable to compete for mates and being unable to compete for resources and dying.
Evolution can only select for that which leads to reproduction and survival of progeny. Whatever happens to an animals body after it passes on genetic material is of no matter to the new animal, excepting where interactions with the existing creature can be of benefit and detriment to the young. A mother crocodile protecting her young will have more surviving young than one that eats them, and the former will tend to out-compete the latter and continue existing.
Assuming a long-lived effectively-immortal species that only reproduces when resources are available for doing so exists, what would happen if a single gene for fast reproduction arose? Resources would run out, and animals would have to start competing with one another over them. Assuming the old and the young are both 50/50 for living or dying in any given fight, the creatures that reproduce slower would be at a disadvantage because there would always be more and more of the fast reproducers.
The only stay for the fast reproducers would be whether they can keep their young alive. So perhaps if they have young one or two at a time instead of twelve at a time, their one or two might be more likely to survive to adulthood whereas the twelve would tend to die well before then.
In the end a balance would emerge where members of the species would tend to reproduce as much as possible where they expect to be able to properly nuture the offspring. Those reproducing slower would fail to compete for resources. Those reproducing faster would fail to keep their offspring alive.
But certainly, those that are steadfastly not reproducing for "the good of the species"? These would be out-competed in short order by the rest.
If you analyze death in humans you will quickly see it's not as simple as you might think. Cells die in humans all the time, in fact millions of your cells will have died before you finish reading this post. Some organs, such as the skin and the colon, depend on killing (ie. triggering programmed cell death) large amounts of their own cells to function, and even internally it is used as a tool where more gentle means would probably work, such as bone growth and repair, which involves large amounts of cells dying.
Second if you analyze what do humans die from if they die "peacefully in their sleep" ? Well they die of "natural causes". That's awfully noninformative. What do you die from, really ? Well, you die from energy exhaustion in your blood, causing multiple organ failure, leading to poisoning, leading to more organ failure, leading to more organ failure, leading to a relatively slow and orderly shutdown of your body. At this point there are certainly things that your body could do to stay alive (all it takes is accelerating energy dumping in the blood), but it doesn't. Your body chooses to die at a certain point, and it very gently kills itself at a certain point. There's a feedback mechanism that makes this happen. It takes something like a few weeks to actually die. People often report that they can feel this happening and the timeframe seems to be such that you have plenty of time to say goodbye or do whatever needs doing.
Because this is how death works in animals, it does mean that if someone dies from natural causes, the organs are thoroughly poisoned and have had to take extreme measures to avoid dieing completely before the body dies. This usually includes sacrificing significant parts of the organs. This means you cannot safely transplant organs from people who die slowly. But this is another subject.
Thirdly while everybody focuses on death, there are pretty serious symptoms that occur, frankly they start happening before you're even born, but by the time you're 60 there will be very obvious external symptoms of aging. Most of the ones we focus on boil down to cell senescence: your cells choose to systematically become less active as they age, and at a certain cell age (measured in generations) they kill themselves, and they are mostly, but not entirely replaced (that's the function of stem cells: replace senescenced cells that have killed themselves, and that's why they're such a big focus for anti-aging research). This is a mechanism that, essentially, stores your age, and the total energy use of the environment of the cell, into every DNA chain in every cell, and responds to it. Your age gets too big, and it kills itself. You use a certain amount of energy over time, and your cells kill themselves. Long before they kill themselves, they will force themselves to use less energy, even when it means things go wrong (this is why you should -and will- systematically eat less as you age).
And of course there are exceptions to death. There is a continuous cell line from every living human (even clones and the like) to the first human pair, and probably even to the very first living organism. So specific cell types, most notably the procreation related cells, are exempt from death. They do age, as in they measure their age, in years and energy, and they do kill themselves (even a lot quicker than normal cells) but they reset their age every time procreation happens. So, assuming you've got children, not all of your cells will die when you die.
There is a clear evolution to death, as a mechanism. Early lifeforms did not age (some are still alive, so we should say "do not age" in a few cases. Some were alive the first time Eve proverbially smiled at Adam and may still be alive when the last human dies). They would die from disease, getting eaten, or simply by getting themselves into a situation where they could not survive (getting buried was pretty popular). Of all of life's "kingdoms", there's 5.
* The Monera (mostly bacteria, mostly single cellular organisms, with many interesting exceptions), do not die of old age. A curious exception is that a number of them have a built-in self destruct (ie. death) if they do not reproduce.
* The Protoctista and Fungi (2 kingdoms). Have chromosomes and a cell nucleus. Some living protocta are hundreds of thousands, maybe even millions, of years old. They are mostly single cellular organisms, but some of them are very big, for example some algae can be 40 meters or longer. The general rule seems to be that sexually reproducing protoctista die, but there are many interesting mechanisms of death found in these cells, rather than just the one we see in higher lifeforms.
Many can "pause" their death clocks. Only time spent eating causes the death countdown to tick and various forms of hibernation do not.
Quite a few are "optionally" sexually reproducing and they disable and reset the death counter when they switch to the asexual mode.
Some have inherited death clocks: organisms can switch to asexual reproduction but their death clocks do not reset upon reproduction. If they, and their offspring, do not switch back before a hundred or so generations, they age, grow weak, and die.
Keep in mind that when single cellular organisms sexually reproduce, they start with 2 cells and end with 4 cells. Mostly, there is no difference between parent and child. They change their own DNA and then divide. So "parents" don't die sooner than their children, and mostly you simply cannot tell the difference between parent and child at all. And all of the cells have their death clocks reset.
Despite being single cellular organisms, they actually have sexual "organs" (parts of the cell dedicated to reproduction alone). Both outer and inner ones : a way to connect the cell membranes together, and dedicated "micronuclei" that actually reproduce. The cell then "kills" (eats-sort of) the "old" cell macronucleus. Generally the new cells immediately recreate their "sexual organs", which are deactivated immediately after creation, and the newly formed cells go about their business under the direction of their new macronucleus.
The "death" of the old nucleus is the first form of death that is encountered in evolution.
The defining feature of death seems to be that DNA is split into two parts: DNA that is used exclusively for reproduction and DNA that is used for, well, anything else. The reason you die is that a human being falls into that second category.
The obvious variant that must have existed yet is missing is the variant we all want to exist: sexual reproduction where the death clock is reset in both parent and child, and the parent DNA is not destroyed. We do not know of any lifeforms that do this.
So there is a simple and inescapable conclusion : sex (the sharing of genetic information of multiple individuals in a species) does not work without death. That is why you die.
Extremely interesting book on the subject: "Sex and the origin of death" [1]
[1] https://www.amazon.com/Sex-Origins-Death-William-Clark/dp/01...
Bees, for example, have evolved to have very strong but non-reproducing organisms in a community. There's still selection pressure on a hive to produce stronger and longer lived workers.
As I understand it, the general mechanism involved here is usually called kin selection, and has been discussed as far back as Darwin, both as a potential problem with the theory and as a fatal defect in the Lamarckian view.
Nature does not have an ageing problem.
Aging and dying is a necessary condition for life to even exist.
It's only humans who have a problem with it.
In other words, the organism's procreation could be more successful if the olds contribute to the youngs survival to reproductive age.
In other other words, you haven't really reproduced if your offspring don't reproduce.
We're so successful that the best strategy for a lot of other animals has been to be food or company. Cows are doing pretty well because of us.
The problems that occur later in life do not have any affect on that. On the other hand, for communities and 'tribes', not keeping old members around make them more responsive to change.
How many of these elders do you need to care for your children though? 2, 4, 8, 16, ...? Maybe grandmother hypothesis works, but evolution would not care much for a great-grandmother hypothesis.
This actually seems consistent with the current lifespan of human beings. Most people have grandparents when they are children. Very few people have great-grandparents.
Why do species have a prime? Why don't they reach a certain "amount of reproductibility" and stay at that constant amount forever?
The fact that a prime exists is just one instance of one of those things that evolution hasn't figured out yet. Or maybe there's a different reason why it hasn't happened, but that reason is certainly not fundamental physics.
The background for this theory is that evolution is gene-centric, not individual-centric. What is fitter is what will better propagate the genes, which is not necessarily what's best for the individual.
So it can build "designs" that have a better chance of propagating genes earlier on, where features that help that (I'm making this example up, but say something like faster growth) may later have a deleterious affect on the individual. And since evolution is gene focused, there's not as much evolutionary pressure for a longer and healthier life for the individual.
In general you can do things significantly faster with a lower number of bits if you leave out the redundancy required for error detection or correction.
But they do. The article argues that molecule ensembles are damaged by thermal motion but there are other ways in which molecules are damaged over time due to chemical and physical stress. Large molecules in the cells are bombarded by caustic chemicals (oxidative stress) and ionising radiation, both of which break chemical bonds. Even without these, many molecules in the cell are only temporally stable and decay over time (e.g. single-stranded RNAs are unstable even ignoring active degradation).
It is altogether accurate (and common!) to describe these processes as ageing on the cellular level.
As you’ve correctly noted, cells constantly repair and replace damaged molecules.
You still see lifetimes next to 'stable' elements because nothing is actually stable on long enough time scales.
Granted, 10^~45 years may seem like a long time, but I am sure it would still feel short if that was the norm. ;-)
Organisms age and die when their cells age and die. An organism can not age and die by either replacing its cells as fast as they die, perfectly, or by having cells that don't die.
Why do cells die? The article presents two views: either they are programmed to, for biological reasons, or they just break down over time, because engineering is hard and physics is a real mother.
It'd be real convenient for us if it was the former, because humans aren't built to have all our cells constantly replaced throughout our life, but this article makes the argument that programmed cell death is unlikely and physical wear and tear more plausible.
It isn't hard to keep any particular process 'alive'. Stars burn for a long time. The hard part comes with maintaining a process that also requires memory of the past. What would seem to be the difference between a star and biological life is that life maintains a record of some information of its past states in its DNA. However, even on top of this, many animals, especially birds and mammals, have to teach their young and train an incredibly complexly connected brain.
So I think what you end up with is an optimization that trades off between these two complexity drives: a mind and a body. An organism that has invested a lot of time into training its nervous system does not want to completely regenerate it and lose all of that information. However, from a bodily perspective, being able to regenerate would be quite useful. However, making processes more reversible comes at a price (notably, thermodynamically, it would take infinite time. computationally, reversibility requires n^2 steps for some irreversible computation done in n steps), one that is no longer worth the tradeoff if the mind cannot be usefully regenerated.
I guess my point overall is that the brain, since it wants to store information, is inherently destined for breakdown. Regenerating it might be possible, but the interconnections might be so complex that it would be energetically infeasible to maintain this complexity. In humans, the brain already utilizes 20% of our energy budget. As the organism as a whole is being optimized through evolution to do evolutionary favorable things with its energy budget, this means that energy spent maintaining itself physically indefinitely is not worth it, as compared to something like a lobster, which ostensibly doesn't have the sorts of pyramidal neurons needed for a truly, truly complex nervous system and thus might as well live forever.
I assume that people will disagree with the idea that the brain is destined to break down, but if you were 10000 years old today, would you still consider yourself the same person that used to hang out with the pharaohs, having learned and forgotten hundreds of languages, names, families? It just gets absurd at some point, and the energy cost of it all is not worth it compared to reboot(strapp)ing everything from the ground up by having a child.
It is interesting the the mole rats are so long lived, and that they are also eusocial. Since institutional memory may be very important to the colony's survival, having long-lived individuals may be very helpful for an animal incapable of writing things down for posterity.
I would still say that this is all very firmly grounded in thermodynamics.
From what I can tell, the reason why aging is so prevalent is that most species haven't had time to evolve the mechanisms that solve the problems that appear later in life. If there's some truth to this, you'd expect that the species that are better at this also tend to be the simpler ones, since for those simplicity also means smaller diversity of things going wrong.