You know, I've recently wondered quite a bit about aging and how any of it makes sense.
What has perplexed me is the notion of honest signals[1] in a world governed by natural selection and the survival of the fittest. Why wouldn't cheating exclusively emerge as the only strategy? Why wouldn't a species evolve a mechanism to survive longer and longer till it completely dominates?
Then it dawned on me that the survival of the species is not aligned with the survival of an individual. Cheating maximizes the benefit to that individual. But possibly damages the collective. Why is why honest signals even exist.
Aging and death as being pre-programmed is in service of the collective and that's why it even exists.
A bit of existential dread. But sharing it nonetheless.
> survival of the species is not aligned with the survival of an individual
The unit of survival is not the individual or the species, but the gene. Genes maximize their survival by combining via sexual reproduction with other genes over time. Any one combination of genes will be out-competed over time.
The reason for honest aging signals is that a gene survives longer by getting out of the way of its offspring's combinations with other, newer genes. Sexual reproduction is the only way to get access to new phenotype features.
It's not service for the collective. Hanging around in one individual is the genetic version of vendor lock-in.
I think it can be instructive to look at other social mammals that range over large areas, like Orca and Elephants. They tend to lean heavily on elder females as the purveyors of tribal knowledge and inter-generational memory to remember where to go and how to get there as environmental conditions vary from year to year and decade to decade. It doesn't matter as much in humans since we have writing and maps now, but this kind of wisdom of those who remember similar lean times from 60 years ago could have been very important to the survival of human communities.
Happy accident at first, though there are some possibilities around grandparents increasing survival rates of younger children, so that would ultimately feed back into the gene pool.
Clearly living longer after viable reproductive age offers something. Having grandmothers around to nurture the second generation offspring is certainly a benefit.
All models are wrong but this one is mine, IANA biologist, yadda yadda.
- there are only so many resources to sustain individuals
- ergo there's a cap of the number of individuals
- ergo some individuals will die, if not from age, from attrition
- if age is not factored in, there are more old individuals, genetic competition between young individuals is reduced as they have to compete for resources with old individuals
- ergo age which kills old individuals irrespective of available resources allows more young individuals to exist in such a pool
- ergo ageing a) promotes competition between young individuals b) increases mixing of the gene pool
- ergo it promotes quicker turnaround on mutations
- ergo ageing is a significant asset in species adaptability to change
IOW vendor lock-in sucks in face of changing conditions as one is suddenly stuck with a suboptimal solution and competitors have a harder time emerging to challenge the status quo.
conversely the benefits of short term ageing are counterbalanced by social effects, where elders, even when not reproductive anymore but still otherwise in good health and thus autonomous as well as minimally consuming resources, are able to provide support for their chain of descendants, freeing energy for parents-to-be to reproduce, then parents to gather more resources that are then directed to support their younglings. The lack of reproductiveness of elders is advantageous to the species as it removes them from the direct gene mixing pool, instead promoting the younger ones.
IOW for its individual lives to be longer, a species goes increasingly social, channeling more support and thus energy towards their younger members, but ageing is still key otherwise the species ability to face quick change (at evolutionary scales) is severely hampered.
The deeper question for me is whether ageing is a specific primary process (a literal clock, which a technique such as the paper would attempt to skew backwards) that emerged from evolution or if it is a secondary effect from entropy corrupting other processes (e.g there's constant degradation + a ton of error correction but at some point degradation is too high and error correction cannot cope, triggering a catastrophic cascading effect leading to the sudden inability for an organism to sustain its own life, which the paper would delay by introducing younger cells, thus less errors, thus error correction can cope for longer)
There's an equilibrium of honesty and dishonesty. If everyone is dishonest, no one trusts, and the dishonesty doesn't pay off. If everyone is honest, everyone trusts, and dishonesty pays off all the more.
So how do group organisms work, there's an in-between where they "trust but verify," meaning lifelong cheaters or slackers eventually get screwed anyway? I know bees can kill their own queen under some circumstances.
> Then it dawned on me that the survival of the species is not aligned with the survival of an individual.
The selfish genes control, and their survival is not perfectly aligned with either the individual or the species. If aging becomes too slow, adaptation slows, and successful genes become more rare and their propagation slows. Genes are replicators, replicators need turn-over to replicate, and greater age means slower turn-over.
It may be that the advent of cultural replicators have decreased the optimal turn-over rate of genetic replicators, but they don't know that.
At the individual and immediate progeny level, aging doesn't affect generation time. If there were group selection it might, as the older people displace resources for the younger, but for an individual that should be dilluted down to no real effect.
Since a given niche can only support a given population size, aging reduces generation time by hitting a ceiling on population size. Some organisms get around this by spawning thousands of offspring and all but approximately one fails fast.
So that's an available trade-off. Increase individual age limits, but maintain adaptation rates by letting many immature individuals compete and die before maturity. Like spermatozoa and tadpoles.
There is no more evolutionary pressure on lifespan after you have children since you have successfully passed on the ‘aging’ gene.
We used to live much shorter lives, being able to die of old age was rare, therefore, no selection.
If we start to have children at 90 years old we may be able to double our lifespans (while the ones that are unable to reproduce earlier will not pass on that inability).
There is no cheating, since we could not modify our genomes and give ourselves superpowers. We cannot live forever because there was no need. We won’t die before we can successfully reproduce.
> There is no more evolutionary pressure on lifespan after you have children since you have successfully passed on the ‘aging’ gene.
This assumes, incorrectly, that each generation of children are birthed into a new separate pocket-universe, where absolutely nothing prior generations do next--including suddenly dying--can ever affect their own trajectories.
Consider genes Alpha and Beta, where Alpha kills women right after menopause, and the Beta lets them live ably to 120. Do you really think there's no difference between the trajectories of clan Alpha and clan Beta?
Or perhaps a Cronus gene [0] which increases fitness and lifespan but causes paranoid infanticide. Just because a gene-copy was made doesn't mean the gene stops mattering.
Elephant matriarchs remember old watering holes that the herd has not visited in decades, and in extreme cases, watering holes that none of the other living members have ever seen.
In drought years these backups may end up getting the herd through the worst of it.
And it turns out that for elephants, water availability is one of the biggest limitations on reproduction. Provide a population with an artificial water source and it will explode in short order.
If your offspring does not survive to reproduce, your genetic lineage disappears, therefore ‘failed’. Others who do not kill their offspring will survive and the species will therefore not exhibit that behavior nor enjoy the benefits of that behavior.
First you declared genes had no evolutionary pressure on longevity after children existed... but now you're amending it to grand-children existing?
Well, what about great-grandchildren? How many more times must you be forced to move the goalposts before realizing that the logic behind them is simply wrong?
You can't just ignore stuff like kin-selection, which we've known about for over a hundred years already.
This is just assuming that the offspring survives just like the parent and reproduces.
If the offspring requires parenting, the parent, once an offspring, also required parenting and so on.
This is not moving the goalpost, it’s doing the similar things adapted in some ways for the environment every generation.
I assumed you were talking about humans. For salmon, the definition of a successful reproductive cycle is simply reproducing. For humans, it takes longer and requires parenting. But genes don’t get selected away when it’s passed on to the next generation.
Interesting thought. So if we simply force people to reprocreate later in life, we'll select for genes that allow for that, possibly also bringing longer lifespans in general (to protect the early offspring.)
I wonder if education, and cultural protection of teenagers has already done that to some extent.
In short, the path to immortality is to hold off children longer and longer... Hypothetically.
> There is no cheating, since we cannot modify our genomes
that reads like you missed the last 10 years of genomics and the Nobel prizes for Jennifer Doudna and Emmanuelle Charpentier, among other proven DNA/RNA manipulations.
your point could turn out true, since edits to genomes AND superpowers resulting is what you said wouldn't work. maybe the second half of the conjunctive clause isn't possible, but we don't know yet.
> Your brain at 90 is mostly useless even if you're not afflicted with a serious condition. You can't learn and adapt
You are factually incorrect. You can, in fact, learn and adapt in your 90s. Sometimes (not always) the brain has degraded and can't do so as well, but that's a problem we should work to fix. And there is some evidence to suggest that cause and effect go in both directions there: if you keep learning and adapting your brain remains more capable of doing so.
People talking about longevity and improving lifespan are primarily not talking about having people go on for centuries looking and feeling like they're 90. They're talking about having people go on for centuries or longer looking and feeling like they're 50 or better. Many of the same things that make us age and die are also what make us have much worse health (physical and mental) in our 90s than in our 40s or 50s. Fixing those things will both help us live longer and help us be healthier for longer.
I said "at 90 you can't learn and adapt like you could in your 20s".
You chose to cut off my quote so it sounds like I said something else, and argue with the strawman you created.
This alone means it's pointless discussing anything with you, as there's no basic intellectual honesty here.
If your claim is that most people at 90 are as intellectually flexible and capable as 20 year old people, that's a rather drastic deviation from basic facts of reality. Another reason it's pointless discussing anything with you.
"We should fix this"... yeah ok, fix it. We're not discussing that, but just mechanically extending days of life. Those two things are not the same thing.
While you're "fixing this" (mental performance at 90) you'll find entropy is rather unforgivable, especially for cells which can't divide so you'll have to essentially completely redo our biology in order to "fix this". Good luck.
They won't help us change our minds though. The problem with having people in their 90's capable of the same things as people in their 30's is that they'd hold positions of power longer. Old ideas would live on much longer
Because right now you don't have the option to choose, so you try to convince yourself that the only choice you have is the one you would have picked anyway. It's quite a common phenomenon, I guess a sort of survival strategy.
There is some truth in saying that science progresses one funeral at a time, and in political structures some of the most effective checks on abuse of power is that even the most shrewd dictator eventually dies.
Longevity has its benefits, but if the powerful people can become effectively immortal, then that does have some risks of dystopian stagnation. Like, imagine USSR if Stalin would never die, or Salazar and Franco still holding power in Portugal and Spain, because democracy only became possible when their health failed; and lack of change at top management of megacorporations and major privately held businesses because their owners and CEOs now can be eternal.
The idea for eternal life is to live with your 18 year old body at 200 years old, not like your 90 year old body now.
I don’t see why we shouldn’t work towards being healthier and younger for longer. The urge to survive is built into us and we can develop the means to achieve it.
That’s not how evolution works. If you do reproduce at 90 then you are by definition capable and will pass those genes on. If that is beneficial your offspring will out-compete the offspring of others whose brains turn to mush.
> People talking about eternal life disgust me. It's narcissism or infantilism in disguise.
I suspect your disgust has prevented you from actually learning what the positions of these people even are. I mean, we've had the story of "aging without dying is bad" since the ancient Greeks and Tithonus, and even for them it was a tragic mistake to forget to ask for the "no more aging please I'm fine at XYZ years" part.
No I see very frequently what "these people" have as a position, you can see it all over this thread. There's no such thing as "no aging". Age is a function of time, you can't stop time. You can hold back on the superficial traits of age, but a human is designed with an expiration date. You can stretch it, you can also cut it short, but you won't get very different productivity in the end.
But most of all. You're not special. I'm not special. Life is not special in each instance. What's special is the system, the collective result of the relentless loop of selection, evolution, adaptation.
Trying to stop death is basically to stop the loop that is life. To stop death is to enforce death. I've seen few comprehend this. You see, you're linked to your environment. Cultural, physical, what have you. As you grasp to stay the same (alive) and the environment changes, you'll naturally fight to hold back the environment from changing. Which will destroy the environment for the next generations.
Hence trying to stop death, causes death. It's not poetic or vague notion. But quite literal.
No. To stop absolutely all change is to enforce death. Aging is just one type of change amongst many that a person can experience.
You may be unable to change in any way but aging, but me?
I may mourn for the "meadow" that I saw being build when I was in infant school being turned into another housing estate when I was an adult, but I know that change is part of life.
I moved country in my mid 30s. I've visited 21 nation states, and seen how different lives can be, and tried learning far too many natural languages.
I'm a furry, so if we solve all the questions in biology (which is probably much harder than SENS, but SENS would give me time to wait), I'll see if being an actual anthropomorphic wolf suits me.
I've not found the right person to start a family with yet, but I'd like to, and I hear parenthood also changes people.
> As you grasp to stay the same (alive) and the environment changes, you'll naturally fight to hold back the environment from changing. Which will destroy the environment for the next generations.
Non sequitur.
Even the first part in isolation, "naturally" doesn't really apply any more, even if for whatever reason a biologically[0] 20-year-old mind with a century of experience is as inflexible as a natural century-old mind, rather than as flexible and open to novelty as a natural 20-year-old.
Both sentences together is even worse, making you absolutely as poetic as you say you're not.
Turtles age. I find it absurd I need to state the obvious. They age and die. They live longer because of their slow metabolism and... well they don't do much.
You'll find it curious I did think about turtles when writing the comment you're responding to. Can you spot the part where I thought about turtles? Something about total productive life? You know, sitting idle for months on end and staring at one point is not exactly what you envisage in your dreams of 150 year old humans or are you? If you want to see turtle-men, visit any nursery home, unfortunately. It's not a happy existence.
Anyway what am I doing, explaining basics to someone who just told me they're "a furry". As I noted people who dream of immortality are either narcissists, or infantile, and I'm sorry to be blunt, but describing yourself as "a furry" strikes me as a combo of both.
This is not a personal attack, but our beliefs shape our opinions, and certain extreme beliefs very much so. You can believe whatever you want to believe, beliefs are free (and most of them among humans are quite mediocre and laughable), but don't expect me to be convinced or entertain your notions.
> Can you spot the part where I thought about turtles?
The picture of a turtle at the of page, and that you stopped reading before the caption that says "some"?
That you definitely didn't look at any evidence linked to from it that directly contradicts your first claim?
And you definitely didn't read what is currently the last sentence of the first paragraph? Which reads:
"""Turtles, for example, were once thought to lack senescence, but more extensive observations have found evidence of decreasing fitness with age.[2]"""
Let alone the table further down? The one which says:
"""Maximum life span
Some examples of maximum observed life span of animals thought to be negligibly senescent are:
Rougheye rockfish 205 years[15][16]
Aldabra giant tortoise 255 years
Lobsters 100+ years (presumed)[17]
Hydras Observed to be biologically immortal[18]
Planaria Observed to be biologically immortal[19]
Sea anemones 60–80 years (generally)[20]
Red sea urchin 200 years[21]
Freshwater pearl mussel 210–250 years[22][23]
Ocean quahog clam 507 years[24]
Greenland shark 400 years[25]"""
(And just in case your eyes glazed over again: Aldabra giant tortoise: 255 years, even that list is not making the claim you're arguing against!)
Also note the distinction between negligible senescence and biological immortality.
> As I noted people who dream of immortality are either narcissists, or infantile, and I'm sorry to be blunt, but describing yourself as "a furry" strikes me as a combo of both.
- "3cats-in-a-coat" demonstrating how to throw stones in a glass house :P
Seriously though, this is all pattern matching to my earlier claim that your disgust prevented you from learning about the topic.
Your claim, which was why I chose to link to the negligible senescence page, was 'There's no such thing as "no aging"'; your claim is demonstrably false even if there's only one single example (https://en.wikipedia.org/wiki/Black_swan_theory etc.), so even mere hydras and planaria, simple as they are, ought to change your mind if you were not simply dismissing what you don't want to be true because you don't like it.
You sound young. Old folks that are still competitive are a force to be reckoned with. They are rare in part because people die, but also the things people compete over feel less important with age.
I'm not young. It's simply that my position is informed by biology, cybernetics and study of evolution, rather than fear of death. And this collective "we'll live forever" pat on the back we give each other is just pathetic TBH, feels very reminiscent to the "healthy at every weight" etc. movements, which seek to build a virtual reality that shields us from basic physiological facts.
Entropy is one of the most relentless forces in the universe. If we could so casually turn it around, this world would be unrecognizable.
Have you ever tried to have a real conversation with someone that old? And I don't mean whatever this cryptic rant is, but an actual attempt at connection between adults.
I have believed that to be the case for a while. It's perfectly logical, from a species point of view.
I also think that we are hardwired not to be able to believe our own lies, because of this. There is (99.9% of the time) a tell, for humans. For someone to effectively lie to us, we need to want to believe the lie, otherwise it fails.
The TV show "Lie to me" is therefore a fascinating exploration (a bit exaggerated in its effectiveness) of how to detect and point out such tells.
This is a lot more compelling when you consider what it takes to survive this generation is not the same thing that was needed to survive last generation. This was more obvious with, for example, the peppered moth.
I'm guessing it's simpler than that. It's hard to keep the seed and mechanisms for reproduction healthy forever. Even if there's no harm to the group, anti-aging might have a cost that reduces the individual's ability to reproduce at an earlier age, or at least it doesn't help.
The longer you live, the less adaptable your species is. The more generations you can have in a shorter amount of time, the faster you can have beneficial mutations that help your species survive changing conditions.
> longer you live, the less adaptable your species is
I live near Yellowstone. There are seasonal hunting grounds the bison, which live a decade or two, won’t cross into. The wolves, meanwhile, don’t live long enough for the lesson to stick. So they continuously cross and get shot.
Humans erected an invisible barrier. The bison adapted where the wolves, arguably the more intelligent creature, did not, in part due to the latter’s short lifespan.
The best of both worlds would be a long-lived polygamous creature that’s constantly reproducing. Ecology, however, proscribes limits on that approach.
I'm not seeing how longevity slows the number of generations you can have per unit of time. That seems like it would be determined by how quickly a species reproduces after being born...not how long they live.
Generally, the more individuals you have competing for resources, the more difficult it is to raise viable offspring. If there are far more elderly individuals who cannot reproduce, they are essentially preventing those resources from being used to mature offspring.
Yes, I thought about that but I went with the general assumption (based on life history theory) that longer lifespans equals longer times to reach sexual maturity.
One interesting thing I had a sense of but only recently could put it into words, in regards to aging-degradation-disease progression, is that there is an inherent mechanism to prune off population that isn't emotional (and perhaps including spiritually) healthy, e.g. there is research that shows that if anger (or any emotion) is being suppressed, then the immune system is also suppressed - meaning more likely to succumb to potential harms of various dis-ease states.
it seems like dishonesty, at least in terms of reproduction, would self correct pretty fast? Like if an animal signals that its strong genetically, but it isnt actually, then its offspring wont fair as well and will be less likely to reproduce, so 'lying' would die off pretty quickly?
> Cheating maximizes the benefit to that individual. But possibly damages the collective.
It would seem like a species that has a language would greatly benefit from having individuals with more years of experience on how to handle infrequent events like droughts, floods, abnormal animal migrations, etc.
And we have. The lifespan of the human individual past its reproductive prime is already impressive. The fact that we take care of our elders instead of just let them die suggest could be a evolutional spandrel but the fact that age and wisdom are associated (at least in "primitive" societies) is a testament to how much of cultural species we are, that is with an unprecedented ability to transmit knowledge necessary for our survival.
Yes, but only as long as they can still communicate and as long as there are no younger experts with comparable experience, if not more up to date, and better motor and communication skills. That puts some limit to useful age.
It's easier to think all the living things are carriers fabricated and controlled by self-replicating nano-bots. Whatever strategy the nano-bots come up with and eventually successfully allowing them to keep creating more nano-bots is the winning strategy.
With tech these bets are off, what if it can further a collective further? Say making you stronger despite your genes, or using tech to assist us. It’s already happening right now, look at all the tech around us
Of note, is that organisms that have a more balanced, symbiotic relationship to their surrounding environment - with shared benefits, live a lot longer. Take thousand year old trees, and millenniums older mycelium networks.
However, this doesnt explain tortoise (or 500 year old sharks)
The amount of energy required to sustain Human growth and Civilization just grows and grows. If we had a scalable balanced, fully renewable resource in everything, we likely would live longer.
- after you reproduce evolutionary pressures have way less leverage and are limited to how an individual effects the copies of their genes that still might reproduce
- excess longevity will result in an older nonreproducing individual competing with copies of its genes leading to evolutionary pressure to die when below a threshold of usefulness to younger generations of your genes
Veratasium just made an approachable video on this subject recently, I definitely recommend. It rebukes the whole 'oh no I just heard what a Nash equilibrium is and now I'm worried cooperation is impossible long term' fears some people interpret his thought experiment (prisoners dillema) to have. Tldr it's rare that you can't coordinate, communicate, or have exactly one trial.
Is the longer tl;dr that with multiple trials and possible miscommunication, the winning individual strategy is tit-for-tat, and the winning group strat is some softer tit-for-tat with one forgivable betrayal?
The winning multi-round group strategy in a game in which you can identify and remember different people is, roughly, "cooperate with cooperators, defect with defectors".
(Also, by way of acknowledging that reality is more complex than simulations like the Prisoner's Dilemma, in reality you might also have options like "stop interacting with defectors in order to avoid lose-lose situations" or "warn others about defectors, and listen to others' warnings but weight them based on whether the entity giving the warning is honest". And conversely, defectors get more options like "pretend to be a different entity with no history" or "pretend to be a known trusted entity".)
What has perplexed me is the notion of honest signals[1] in a world governed by natural selection and the survival of the fittest. Why wouldn't cheating exclusively emerge as the only strategy? Why wouldn't a species evolve a mechanism to survive longer and longer till it completely dominates?
Then it dawned on me that the survival of the species is not aligned with the survival of an individual. Cheating maximizes the benefit to that individual. But possibly damages the collective. Why is why honest signals even exist.
Aging and death as being pre-programmed is in service of the collective and that's why it even exists.
A bit of existential dread. But sharing it nonetheless.
[1] https://en.wikipedia.org/wiki/Signalling_theory