5 ms·

Grandparents contribute to the survival of their grandchildren. Evolution has selected for long lived grandparents. The same thing happened in elephants and wha

by sjducb 2y ago

Grandparents contribute to the survival of their grandchildren. Evolution has selected for long lived grandparents. The same thing happened in elephants and whales.

hirenj 2y ago
This is my favourite bit of research regarding the grandmother effect - linking pathogen evasion to neuroprotective activities in old age, all at the molecular level, in an evolutionary context. https://pubmed.ncbi.nlm.nih.gov/35809046/ https://pubmed.ncbi.nlm.nih.gov/35809046/
roenxi 2y ago
True in the sense that evolution does select for populations with grandparents, but not entirely obvious in the sense that it is optimising the long lifetime of those grandparents. You don't need a lot of grandparents lying around in the community evolutionary speaking, they take resources to maintain. And there might be a limit to how long knowledge is useful for that evolution has sniffed out and calibrated lifespans to. Human life seems to go through 3-4 phases (roughly youth, middle age and old age). The role of each of those is distinct and fairly clear, but it isn't easy to pick why evolution settled on specific numbers of years.
aziaziazi 2y ago
GP used to live within their family, caring of kids and helping with vegetable garden. Their modern “living” in hospices, hospitals, far away neighborhood or vacation resorts have a minor effect on survival on their grand children. Probably negative effect for some pension systems.
- Lutger 2y ago
  By the age we currently stop being 'useful' as members of clan human, i.e. retirement, our forefathers in an evolutionary sense could already have been (great) great grandfathers. Our life as a pensionado or geriatric patient is already a form of life extension, an extra age compared to the stages we used to go through. Evolution doesn't mean only what is useful stays, it is only when selected for under evolutionary pressure that things are forced to go a certain way, and only after many generations. The uselessness of old age will only affect evolution if A) there will be a society that is mad enough to really 'do something about it' and B) such a society will eventually outcompete other ways of life and its values start to dominate. I can imagine a politics where money spend on welfare and healthcare for elderly is minimized to such an extent that life expectancy starts dropping significantly. In a way, the US has something like such a 'make money or die' politics and indeed, life expectancy there is quite a bit lower than would you would expect from such as prosperous nation. Can be economically effective. But it competes which economies where people are productive at an older age, being more focused on staying healthy and significantly less stressed.
- sjducb 2y ago
  Yes our modern world does not make good use of grandparents. Given enough time you might expect that the cost of carrying elderly relatives is enough to select for quick dying grandparents. It might also select for healthy long lived grandparents who are not a burden. Probably both will be selected for in parallel .
  - JumpCrisscross 2y ago
    > our modern world does not make good use of grandparents Senior citizens today probably have more power (and productivity) than they ever have.
    - b112 2y ago
      Distracting grandkids with stories, or showing them how to do things is a superpower. Grandparents used to be younger, too. Women used to have kids before 20, often at 15. You could be a grandparent at 30. But even old and infirm, still stories could be told, and caring for grandma was distracting for kids too. There were a lot more kids too. Most women gave birth yearly, and yes more died, but there were still more. Keeping those kids busy was a plus. Training them vital.
  - jjallen 2y ago
    The cost doesn’t affect the survival of the descendants though. It has to to affect the gene pool.
- dmd 2y ago
  When we're talking about evolution (of something like a human, not a bacterium or fruit fly) you can basically ignore anything that's happened in the last 25,000 years as an irrelevant blink-of-the-eye, timescale-wise. Last 100 years? Forget it.
  - sharpshadow 2y ago
    I don’t know the vaccine evolution came very quickly and we arrived at DNA and RNA modification levels which are able to shape our further evolution for ever.
  - imtringued 2y ago
    The speed of evolution is faster than you think. The reason for that is that mammals rely on sexual selection instead of random mutations. This means that the prevalence of a gene within a population can rapidly change from say 1% of the population to 60% of the population within a few generations.
  - fpoling 2y ago
    Evolution can trivially happen within one generation. Just consider lactose tolerance. If it happens that the only source of food is milk for a substantial period, then anybody with lactose intolerance dies and the relevant genes can go from being rare to being 100% in the population.
- deleted 2y ago
  [deleted]
layer8 2y ago
What are you basing this assessment on?
- sjducb 2y ago
  https://en.m.wikipedia.org/wiki/Grandmother_hypothesis https://en.m.wikipedia.org/wiki/Grandmother_hypothesis

by sjducb 2y ago

Grandparents contribute to the survival of their grandchildren. Evolution has selected for long lived grandparents. The same thing happened in elephants and whales.

hirenj 2y ago

This is my favourite bit of research regarding the grandmother effect - linking pathogen evasion to neuroprotective activities in old age, all at the molecular level, in an evolutionary context. https://pubmed.ncbi.nlm.nih.gov/35809046/ https://pubmed.ncbi.nlm.nih.gov/35809046/

roenxi 2y ago

True in the sense that evolution does select for populations with grandparents, but not entirely obvious in the sense that it is optimising the long lifetime of those grandparents. You don't need a lot of grandparents lying around in the community evolutionary speaking, they take resources to maintain. And there might be a limit to how long knowledge is useful for that evolution has sniffed out and calibrated lifespans to. Human life seems to go through 3-4 phases (roughly youth, middle age and old age). The role of each of those is distinct and fairly clear, but it isn't easy to pick why evolution settled on specific numbers of years.

aziaziazi 2y ago

GP used to live within their family, caring of kids and helping with vegetable garden. Their modern “living” in hospices, hospitals, far away neighborhood or vacation resorts have a minor effect on survival on their grand children. Probably negative effect for some pension systems.

Lutger 2y ago
By the age we currently stop being 'useful' as members of clan human, i.e. retirement, our forefathers in an evolutionary sense could already have been (great) great grandfathers. Our life as a pensionado or geriatric patient is already a form of life extension, an extra age compared to the stages we used to go through. Evolution doesn't mean only what is useful stays, it is only when selected for under evolutionary pressure that things are forced to go a certain way, and only after many generations. The uselessness of old age will only affect evolution if A) there will be a society that is mad enough to really 'do something about it' and B) such a society will eventually outcompete other ways of life and its values start to dominate. I can imagine a politics where money spend on welfare and healthcare for elderly is minimized to such an extent that life expectancy starts dropping significantly. In a way, the US has something like such a 'make money or die' politics and indeed, life expectancy there is quite a bit lower than would you would expect from such as prosperous nation. Can be economically effective. But it competes which economies where people are productive at an older age, being more focused on staying healthy and significantly less stressed.
sjducb 2y ago
Yes our modern world does not make good use of grandparents. Given enough time you might expect that the cost of carrying elderly relatives is enough to select for quick dying grandparents. It might also select for healthy long lived grandparents who are not a burden. Probably both will be selected for in parallel .
- JumpCrisscross 2y ago
  > our modern world does not make good use of grandparents Senior citizens today probably have more power (and productivity) than they ever have.
  - b112 2y ago
    Distracting grandkids with stories, or showing them how to do things is a superpower. Grandparents used to be younger, too. Women used to have kids before 20, often at 15. You could be a grandparent at 30. But even old and infirm, still stories could be told, and caring for grandma was distracting for kids too. There were a lot more kids too. Most women gave birth yearly, and yes more died, but there were still more. Keeping those kids busy was a plus. Training them vital.
- jjallen 2y ago
  The cost doesn’t affect the survival of the descendants though. It has to to affect the gene pool.
dmd 2y ago
When we're talking about evolution (of something like a human, not a bacterium or fruit fly) you can basically ignore anything that's happened in the last 25,000 years as an irrelevant blink-of-the-eye, timescale-wise. Last 100 years? Forget it.
- sharpshadow 2y ago
  I don’t know the vaccine evolution came very quickly and we arrived at DNA and RNA modification levels which are able to shape our further evolution for ever.
- imtringued 2y ago
  The speed of evolution is faster than you think. The reason for that is that mammals rely on sexual selection instead of random mutations. This means that the prevalence of a gene within a population can rapidly change from say 1% of the population to 60% of the population within a few generations.
- fpoling 2y ago
  Evolution can trivially happen within one generation. Just consider lactose tolerance. If it happens that the only source of food is milk for a substantial period, then anybody with lactose intolerance dies and the relevant genes can go from being rare to being 100% in the population.
deleted 2y ago
[deleted]

layer8 2y ago

What are you basing this assessment on?

sjducb 2y ago
https://en.m.wikipedia.org/wiki/Grandmother_hypothesis https://en.m.wikipedia.org/wiki/Grandmother_hypothesis