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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

#41

Post by JumpCrisscross »

"As a worm ages, the quality of its eggs or sperm declines — what we refer to as the ticking of a biological clock. The decline is also reflected in the germ cells’ changing ability to transmit signals from the brain’s mitochondria, he suggested. As the worm grows older, its germline transmits the repair signal less effectively, and so its body declines, too.

Scientists don’t yet know whether these findings apply to humans and how we age. Still, the hypothesis makes sense from a broader evolutionary standpoint, Dillin said. As long as the germ cells are healthy, they send pro-survival signals to ensure that their host organism survives to reproduce. But as the quality of the germ cells declines, there is no evolutionary reason to keep extending life span further; from evolution’s perspective, life exists to reproduce itself."

Curious what effect castration has on this mechanism.

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

#42

Post by jjtheblunt »

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…

> 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.

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

#43

Post by JoshTriplett »

hot_gril wrote: post #28
hughesjj wrote: post #27

Earlier quoted context omitted.

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=v8FvrfMC…

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 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".)

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

#45

Post by alexschnapp »

jjtheblunt wrote: post #42
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 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.

Edited to past tense ‘could not’

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

#46

Post by ben_w »

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]

> 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.

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

#47

Post by yarg »

JumpCrisscross wrote: post #41

"As a worm ages, the quality of its eggs or sperm declines — what we refer to as the ticking of a biological clock. The decline is also reflected in the germ cells’ changing ability to transmit signals from the brain’s mitochondria, he suggested. As the worm grows older, its germline transmits the repair signal less effectively, and so its body declines, too. Scientists don’t yet know whether these findings apply to…

> But as the quality of the germ cells declines, there is no evolutionary reason to keep extending life span further; from evolution’s perspective, life exists to reproduce itself.

When the individual's survival is the only selection factor, this is true - but it ceases to be the case in social species where reproductively non-viable individuals can still positively influence the reproductive chances of the young.

This may be an indirect feedback loop - but a little bit of latency doesn't make a huge difference when you're dealing with hundreds of thousands of generations of natural selection.

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

#48

Post by jjtheblunt »

alexschnapp wrote: post #45
jjtheblunt wrote: post #42

Earlier quoted context omitted.

> 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.

Edited to past tense ‘could not’

that makes sense!

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.

i guess the future will be interesting!

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

#50

Post by Terr_ »

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…

> 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.

[0] https://en.wikipedia.org/wiki/Saturn_Devouring_His_Son

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