8 ms·

The headline's premise does not square with the fact that there are organisms that don't age and whose life span is only limited diseases, accidents and predati

The headline's premise does not square with the fact that there are organisms that don't age and whose life span is only limited diseases, accidents and predation. https://en.wikipedia.org/wiki/Negligible_senescence https://en.wikipedia.org/wiki/Negligible_senescence That strongly points toward a biological reason for aging. I mean, sure, the heat death of the universe is inevitable, but that is not even remotely on the same time scale as the life span of complex organisms.

contravariant 9y ago
Maybe the headline is somewhat flawed, but objects with negligible senescence are discussed in the article. According to the article the only difference between organisms with and without negligible senescence is whether there is a possibility for damage to accumulate.
- Karlozkiller 9y ago
  But wouldn't aging be exactly that damage accumulation? Are we then not saying 'not aging is impossible, here are some examples of things not aging' ?
  - IntronExon 9y ago
    Aging is a “planned” process, damage is just damage. Shortening telomeres with reproduction, cell senescence, loss of reproductive viability are not damage, they’re age related. UV light knocking a base pair out of a whack is damage. If you live long enough, you will accumulate damage even in the absence of aging. The hope for humans is thst we develop means to both halt aging, and repair accumulated damage.
- rowyourboat 9y ago
  Where exactly does he discuss that? His entire point seems to be that aging is inevitable: > The constant risk is environmental (accidents, infectious disease), but much of the exponentially increasing risk is due to internal wear. ... but as examples of negligible senescence show, that is simply not the case. This "exponentially increasing risk" is just not a given.
  - saalweachter 9y ago
    The author gets into it in the comments (which are now two years old at this point?).
brlewis 9y ago
That none of the longest-lived organisms are warm-blooded squares well with the article's premise that physical heat damage causes aging.
- ecpottinger 9y ago
  Then how do you account for mole-rats. http://experimentalbiology.org/getattachment/2014/About-EB/Press/Press-Releases/Rodriguez-Buffenstein-Release-FINAL.pdf.aspx http://experimentalbiology.org/getattachment/2014/About-EB/P...
  - brlewis 9y ago
    Interesting...that's different, and does not square with the article's premise. It does not sound like that organism is just getting longer life by keeping its cells in the refrigerator. Especially this part: "Naked mole rats also appear to remain spry and healthy even in the final years of their long lives" Sounds like they changed the shape of the curve, not merely stretching it out.
  - atmanthedog 9y ago
    My best guess would be that they are so because they are eusocial. As I posted in a comment below somewhere, I think it is the complexity of the nervous system that drives a tradeoff with repairable bodies. A brain does not want to have to retrain itself, but the history it stores makes it entropically very energy intensive to maintain. I think this drives most of what we see here: things without complex nervous systems (pyramidal neurons and such) have no disincentive in persisting indefinitely, because their relatively simple nervous system does not take increasing amounts of energy to maintain, and thus they can budget their energy for growing and other evolutionary benefits. Most mammals have to budget their energy such that they can maintain the state of their brain, and thus have a disincentive for eternal aging: we either need to start forgetting earlier memories, which could potentially be bad, or we have to start paying the energy price of maintaining a very complex system. Energy usage tends to get optimized by evolution, so then, we end up trading off longevity. Mole rats, however, being eusocial, have a different evolutionary strategy than most mammals. Since the entire colony effectively behaves as a single metaorganism, losing its experienced members is particularly painful if they have valuable institutional memory. Thus, there is stronger evolutionary pressure to pay the cost of maintaining these systems. (I realize that isn't really what you were commenting about, but it does give a thermodynamic reason for their longevity, but not one simply based on temperature.)
klmr 9y ago
> The headline's premise The author mentions in a comment that he didn’t write the headline (as is so often the case). His original headline (“Aging: where physics meets biology”) is much less controversial.
- Maybestring 9y ago
  Nautilus, this may get you more page hits, but it's not convincing me to renew my subscription.
  - bendbro 9y ago
    You'll need to tell that to the middling middle manager trying to improve his KPI.
- ashelmire 9y ago
  This is why I take issue with the way link aggregators handle title rules. The title of a popular article is usually written by someone other than the article's author (by a headline writer instead) in order to provoke more of a response. I think we should make an effort to reflect the content of the article, rather than take the misleading headline.
  - nightski 9y ago
    Whether you take issue or not is irrelevant. It works, or it wouldn't be done. The real world sucks. I mean it's the same reason we are still, in 2018, using JavaScript for large application development. Best just get used to it.
    - jonathanyc 9y ago
      Evidently it does not work for GP. “This is what’s done” is hardly a counterargument to “I think we should change this.” It’s even weaker of a counterargument than “I actually like how it is.”
      - 9y ago
BurningFrog 9y ago
Even humans don't age, in the sense of becoming more feeble, in our first 20 years. We actually do the opposite!

contravariant 9y ago

Maybe the headline is somewhat flawed, but objects with negligible senescence are discussed in the article. According to the article the only difference between organisms with and without negligible senescence is whether there is a possibility for damage to accumulate.

Karlozkiller 9y ago
But wouldn't aging be exactly that damage accumulation? Are we then not saying 'not aging is impossible, here are some examples of things not aging' ?
- IntronExon 9y ago
  Aging is a “planned” process, damage is just damage. Shortening telomeres with reproduction, cell senescence, loss of reproductive viability are not damage, they’re age related. UV light knocking a base pair out of a whack is damage. If you live long enough, you will accumulate damage even in the absence of aging. The hope for humans is thst we develop means to both halt aging, and repair accumulated damage.
rowyourboat 9y ago
Where exactly does he discuss that? His entire point seems to be that aging is inevitable: > The constant risk is environmental (accidents, infectious disease), but much of the exponentially increasing risk is due to internal wear. ... but as examples of negligible senescence show, that is simply not the case. This "exponentially increasing risk" is just not a given.
- saalweachter 9y ago
  The author gets into it in the comments (which are now two years old at this point?).

brlewis 9y ago

That none of the longest-lived organisms are warm-blooded squares well with the article's premise that physical heat damage causes aging.

ecpottinger 9y ago
Then how do you account for mole-rats. http://experimentalbiology.org/getattachment/2014/About-EB/Press/Press-Releases/Rodriguez-Buffenstein-Release-FINAL.pdf.aspx http://experimentalbiology.org/getattachment/2014/About-EB/P...
- brlewis 9y ago
  Interesting...that's different, and does not square with the article's premise. It does not sound like that organism is just getting longer life by keeping its cells in the refrigerator. Especially this part: "Naked mole rats also appear to remain spry and healthy even in the final years of their long lives" Sounds like they changed the shape of the curve, not merely stretching it out.
- atmanthedog 9y ago
  My best guess would be that they are so because they are eusocial. As I posted in a comment below somewhere, I think it is the complexity of the nervous system that drives a tradeoff with repairable bodies. A brain does not want to have to retrain itself, but the history it stores makes it entropically very energy intensive to maintain. I think this drives most of what we see here: things without complex nervous systems (pyramidal neurons and such) have no disincentive in persisting indefinitely, because their relatively simple nervous system does not take increasing amounts of energy to maintain, and thus they can budget their energy for growing and other evolutionary benefits. Most mammals have to budget their energy such that they can maintain the state of their brain, and thus have a disincentive for eternal aging: we either need to start forgetting earlier memories, which could potentially be bad, or we have to start paying the energy price of maintaining a very complex system. Energy usage tends to get optimized by evolution, so then, we end up trading off longevity. Mole rats, however, being eusocial, have a different evolutionary strategy than most mammals. Since the entire colony effectively behaves as a single metaorganism, losing its experienced members is particularly painful if they have valuable institutional memory. Thus, there is stronger evolutionary pressure to pay the cost of maintaining these systems. (I realize that isn't really what you were commenting about, but it does give a thermodynamic reason for their longevity, but not one simply based on temperature.)

klmr 9y ago

> The headline's premise The author mentions in a comment that he didn’t write the headline (as is so often the case). His original headline (“Aging: where physics meets biology”) is much less controversial.

Maybestring 9y ago
Nautilus, this may get you more page hits, but it's not convincing me to renew my subscription.
- bendbro 9y ago
  You'll need to tell that to the middling middle manager trying to improve his KPI.
ashelmire 9y ago
This is why I take issue with the way link aggregators handle title rules. The title of a popular article is usually written by someone other than the article's author (by a headline writer instead) in order to provoke more of a response. I think we should make an effort to reflect the content of the article, rather than take the misleading headline.
- nightski 9y ago
  Whether you take issue or not is irrelevant. It works, or it wouldn't be done. The real world sucks. I mean it's the same reason we are still, in 2018, using JavaScript for large application development. Best just get used to it.
  - jonathanyc 9y ago
    Evidently it does not work for GP. “This is what’s done” is hardly a counterargument to “I think we should change this.” It’s even weaker of a counterargument than “I actually like how it is.”
    - 9y ago

BurningFrog 9y ago

Even humans don't age, in the sense of becoming more feeble, in our first 20 years. We actually do the opposite!