Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Cells across the body talk to each other about aging

quantamagazine.org

Post reply on HN
Print view View original

71–80 of 173 posts

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

#71

Post by whythre »

ttoinou wrote: post #60
bhuga wrote: post #52

Earlier quoted context omitted.

> 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 ?

Clearly living longer after viable reproductive age offers something. Having grandmothers around to nurture the second generation offspring is certainly a benefit.

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

#72

Post by tommychillfiger »

phkahler wrote: post #56

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…

I'm primed to agree as I like running, and running appears to increase mitochondrial function and density. It also appears to have some anti aging effects, which would track.

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

#73

Post by colechristensen »

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…

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

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

#74

Post by alexschnapp »

Terr_ wrote: post #65
alexschnapp wrote: post #58

Earlier quoted context omitted.

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.

> If your offspring does not survive to reproduce 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 kn…

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.

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

#75

Post by evantbyrne »

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]

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.

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

#76

Post by wizzwizz4 »

ttoinou wrote: post #60
bhuga wrote: post #52

Earlier quoted context omitted.

> 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 ?

Kin selection. Parents, and community in general, are kinda important for the survival of a child.

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

#77

Post by alexschnapp »

hwbehrens wrote: post #68
alexschnapp wrote: post #58

Earlier quoted context omitted.

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.

That's precisely the point the parent was trying to make to your GP post, namely that > "There is no more evolutionary pressure on lifespan after you have children" is an inaccurate oversimplification.

The definition of having children varies by species. For humans, it requires parenting and care, for salmon, just the act of reproduction works.

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

#78

Post by anigbrowl »

jdjdjdkdksmdnd wrote: post #44

how does anyone deny the epigenetic model of aging demonstrated by david sinclair?

Effective advocacy begins with letting go of the assumption that everyone already knows about the things you know about. I'm sure this person is well known within the bioscience community, but this is the first time I'd heard of him or his model.

https://www.nad.com/news/harvard-professor-david-sinclairs-i...

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

#79

Post by ben_w »

polishdude20 wrote: post #61
JoshTriplett wrote: post #40

Earlier quoted context omitted.

> 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…

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

How can you be so confident about a hypothetical with zero examples? All the 90 year olds today are necessarily stuck with 90 year old brains.

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

#80

Post by JoshTriplett »

ben_w wrote: post #79
polishdude20 wrote: post #61

Earlier quoted context omitted.

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

How can you be so confident about a hypothetical with zero examples? All the 90 year olds today are necessarily stuck with 90 year old brains.

Indeed. And why advocate death as the solution to a problem better handled with term limits and similar mechanisms?
Post reply on HN