15 ms·

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 gov

• kraftman 3y ago
  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?
  • Centigonal 3y ago
    I think it's difficult to signal genetic fitness without actually being genetically fit. There are proxies to genetic fitness that are frequently and successfully mimicked, though. See e.g.: https://en.wikipedia.org/wiki/Batesian_mimicry https://en.wikipedia.org/wiki/Batesian_mimicry
  • lanstin 3y ago
    If your fake out display of fitness is attractive to the other sex, then it is actual reproductive fitness.
• deadbabe 3y ago
  Cheating could just get you killed off by jealous partners, cutting off your ability to reproduce more. It’s like marking territory.
• kiba 3y ago
  Aging being preprogrammed is only one hypothesis. The other hypothesis is that the evolution only selected for what work and reproduced. Note what work and reproduced is only a minimum bar.
• block_dagger 3y ago
  > Why wouldn't a species evolve a mechanism to survive longer and longer till it completely dominates? Because evolution happens faster with sexually reproducing generations that die out to leave room for the fitter youth.
  • deleted 3y ago
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  • taeric 3y ago
    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.
    • pmontra 3y ago
      I didn't know about it. Thanks. Link to the Wikipedia article https://en.wikipedia.org/wiki/Peppered_moth_evolution https://en.wikipedia.org/wiki/Peppered_moth_evolution
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• samstave 3y ago
  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.
• huytersd 3y ago
  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.
  • troupe 3y ago
    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.
    • huytersd 3y ago
      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.
    • I_Am_Nous 3y ago
      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.
  • JumpCrisscross 3y ago
    > 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.
• atticora 3y ago
  > 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.
  • cma 3y ago
    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.
    • atticora 3y ago
      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.
      • cma 3y ago
        > aging reduces generation time by hitting a ceiling on population size. That's what I meant by "if there were group selection it might, as the older people displace resources for the younger."
• jxy 3y ago
  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.
• amadeuspagel 3y ago
  Group Selection is not a thing[1]. 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. [1]: https://en.wikipedia.org/wiki/Group_selection#Criticism https://en.wikipedia.org/wiki/Group_selection#Criticism
  • hot_gril 3y ago
    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.
  • redmen 3y ago
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  • redmen 3y ago
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• m3kw9 3y ago
  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
• troupe 3y ago
  > 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.
  • pmontra 3y ago
    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.
  • cassepipe 3y ago
    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.
• hot_gril 3y ago
  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.
• Shorel 3y ago
  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.
• hughesjj 3y ago
  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. https://youtu.be/mScpHTIi-kM?si=v8FvrfMCHioLJET5 https://youtu.be/mScpHTIi-kM?si=v8FvrfMCHioLJET5
  • hot_gril 3y ago
    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?
    • JoshTriplett 3y ago
      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". https://ncase.me/trust/ https://ncase.me/trust/ is well worth playing to get an idea of how this works. (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".)
      • hot_gril 3y ago
        Yep, I remember playing that minigame a while back, it's a nice one. Also the "wisdom of crowds" one on that same site.
• alexschnapp 3y ago
  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.
  • 3cats-in-a-coat 3y ago
    [flagged]
    • alexschnapp 3y ago
      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.
      • mulmen 3y ago
        My personal preference is for my 25 year old body but I will settle for 18.
    • mulmen 3y ago
      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.
    • JoshTriplett 3y ago
      > 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.
• bhuga 3y ago
  > 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.
  • ttoinou 3y ago
    Why would women survive so long after menopause then ?
    • ysofunny 3y ago
      better curated memes which are an expression of the concept of gene over the field of informatics, instead of the field of biology (unit cells vs unit bits)
    • mrkstu 3y ago
      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.
    • tarkin2 3y ago
      To help her offspring propogate her genes is one theory I've read, coming from observing post menopausal sharkes
    • whythre 3y ago
      Clearly living longer after viable reproductive age offers something. Having grandmothers around to nurture the second generation offspring is certainly a benefit.
    • wizzwizz4 3y ago
      Kin selection. Parents, and community in general, are kinda important for the survival of a child.
• loceng 3y ago
  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.
• Kalanos 3y ago
  because game theory, and we would evolve to recognize cheating
• colechristensen 3y ago
  Two things: - 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
• qp11 3y ago
  Same reason everything doesn't turn into a predator or a parasite. We get ecosystem collapse as soon as that happens.