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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

#31

Post by 3cats-in-a-coat »

alexschnapp wrote: post #29
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…

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…

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

#32

Post by pmontra »

taeric wrote: post #14
block_dagger wrote: post #7

Earlier quoted context omitted.

> 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.

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 didn't know about it. Thanks.

Link to the Wikipedia article https://en.wikipedia.org/wiki/Peppered_moth_evolution

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

#33

Post by hot_gril »

amadeuspagel wrote: post #16
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…

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

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.

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

#35

Post by alexschnapp »

3cats-in-a-coat wrote: post #31
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…

[flagged]

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.

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

#36

Post by mulmen »

3cats-in-a-coat wrote: post #31
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…

[flagged]

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.

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

#37

Post by cassepipe »

troupe wrote: post #23
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…

> 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.

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

#38

Post by mulmen »

alexschnapp wrote: post #35
3cats-in-a-coat wrote: post #31

Earlier quoted context omitted.

[flagged]

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.

My personal preference is for my 25 year old body but I will settle for 18.

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

#39

Post by cma »

atticora wrote: post #11
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…

> 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.

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

#40

Post by JoshTriplett »

3cats-in-a-coat wrote: post #31
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…

[flagged]

> 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.

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