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Cells across the body talk to each other about aging

quantamagazine.org

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Re: Cells across the body talk to each other about aging

#51

Post by hot_gril »

JoshTriplett wrote: post #43
hot_gril wrote: post #28

Earlier quoted context omitted.

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". 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 w…

Yep, I remember playing that minigame a while back, it's a nice one. Also the "wisdom of crowds" one on that same site.

Re: Cells across the body talk to each other about aging

#52

Post by bhuga »

LASR wrote: post #3

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 surviva…

> 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.

Re: Cells across the body talk to each other about aging

#53

Post by redcobra762 »

fnordpiglet wrote: post #25
redcobra762 wrote: post #19

Earlier quoted context omitted.

which have cells like humans

All living things have at least one cell, but they do not all operate in the same way. There’s possibility that worm cells and human cells behave similarly in this, but it’s also fully possible they behave in very dissimilar ways.

Which is why this is interesting! I just wanted to combat the whole "this isn't relevant to humans" pushback. There's potential value here.

Re: Cells across the body talk to each other about aging

#54

Post by atticora »

cma wrote: post #39
atticora wrote: post #11

Earlier quoted context omitted.

> 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 s…

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.

Re: Cells across the body talk to each other about aging

#55

Post by lanstin »

kraftman wrote: post #4
LASR wrote: post #3

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 surviva…

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?

If your fake out display of fitness is attractive to the other sex, then it is actual reproductive fitness.

Re: Cells across the body talk to each other about aging

#56

Post by phkahler »

I've come to think mitochondria are somehow fundamental to health in ways we can't even see. No sources, but they seem relevant to structure of the overall organism, proper healing of wounds, something in the brain (they can move between neurons), apoptosis, and a few other odd things I've seen talked about. They also come up in any number of diseases and conditions. All far beyond what you'd expect from "powerhouse of the cell" producing ATP.

Re: Cells across the body talk to each other about aging

#57

Post by loceng »

LASR wrote: post #3

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 surviva…

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.

Re: Cells across the body talk to each other about aging

#58

Post by alexschnapp »

Terr_ wrote: post #50
alexschnapp wrote: post #29

Earlier quoted context omitted.

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 cheati…

> 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…

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.

Re: Cells across the body talk to each other about aging

#59

Post by lanstin »

andrewstuart wrote: post #34

As you get older you find it becomes a key topic of conversation not just amongst your cells but amongst friends - the conversation always heads towards whatever ailment or problem your body has recently dealt you.

This effect, which I can confirm in more than set of friends, is one of the most annoying aspects of aging. I'd rather gossip about the cheer leaders or the football players than listen to people talk about procedures. I certain have a lot more aches and pains but I don't care to let my attention linger on them.

Re: Cells across the body talk to each other about aging

#60

Post by ttoinou »

bhuga wrote: post #52
LASR wrote: post #3

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 surviva…

> 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 com…

Why would women survive so long after menopause then ?
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