4 ms·

The elderly would have to specifically help their own grandchildren, not just the community, for evolution to have an effect (otherwise you’re talking group sel

The elderly would have to specifically help their own grandchildren, not just the community, for evolution to have an effect (otherwise you’re talking group selection nonsense). I’d imagine it’s debatable whether elderly grandparents past reproductive years are helping their grandchildren be more reproductively successful. Possible, but not a forgone conclusion by any means.

deleted 7y ago
[deleted]
barry-cotter 7y ago
Grandmothers increase their offspring’s genetic impact, for daughters by increasing survival rates, for sons by increasing numbers of offspring. http://en.wikipedia.org/wiki/Grandmother_hypothesis http://en.wikipedia.org/wiki/Grandmother_hypothesis > The grandmother hypothesis is a hypothesis to explain the existence of menopause in human life history by identifying the adaptive value of extended kin networking. It builds on the previously postulated "mother hypothesis" which states that as mothers age, the costs of reproducing become greater, and energy devoted to those activities would be better spent helping her offspring in their reproductive efforts. It suggests that by redirecting their energy onto those of their offspring, grandmothers can better ensure the survival of their genes through younger generations.
- bilbo0s 7y ago
  That's a hypothesis. Again, reproduction is happening prior to any potential partner even knowing of a grandmother in many places in the animal kingdom. Even for humans actually. So you're subscribing to the more adaptationalist line of reasoning for the existence of menopause. Which is fine. But you should concede that fact. Many others might subscribe to any of the other hypotheses for reproductive senescence. I subscribe to the artifactualist line of reasoning. ie - people just started living too long, and our bodies adapted for a 20-40 year life span. But there are numerous other hypotheses out there, many of them every bit as plausible as my artifactualist hypothesis. I only subscribe to the artifactualist hypothesis because it is the hypothesis most in line with the theory of evolution.
  - gowld 7y ago
    How long is too long? A woman is fertile through age 40 (and useful to care for offspring for another 10-20 years), a man is fertile through age 80 (and a genetically fit male would have valuable sperm long after his fitness showed in his phenotype). Why would our bodies adapt for a 20-40 year life span?
- crazydoggers 7y ago
  If the grandmother hypothesis is true, then you’re still talking kin selection effect via grandparents, which is very different than group selection. I concede that kin selection is very possible, but again, as this is an unproven hypothesis at the moment, still a matter of scientific debate, hence not really clear or obvious.
murkle 7y ago
Yes, interesting question. Some relevant research: https://www.earth.com/news/kids-benefit-grandmother-healthy/ https://www.earth.com/news/kids-benefit-grandmother-healthy/ Edit: and https://www.cam.ac.uk/research/news/the-importance-of-grandmothers-in-the-lives-of-their-grandchildren https://www.cam.ac.uk/research/news/the-importance-of-grandm... Edit2: and https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.160069 https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.1600...
isolli 7y ago
Actually this has been studied, establishing for instance the grandmother effect in pre-industrial Canada [0] ("women with mothers nearby had more and healthier children"). See [1] for more resources. Anecdotally, I can personally attest that having grandparents too far to help makes it a lot harder to raise our two young children - there will certainly not be a third one. [0] https://www.cbc.ca/news/canada/montreal/grandmother-effect-1.5016545 https://www.cbc.ca/news/canada/montreal/grandmother-effect-1... [1] http://sacha-engelhardt.feedsrss.com/ http://sacha-engelhardt.feedsrss.com/
- crazydoggers 7y ago
  Just to clarify, this would be a kin selection effect, not a group selection effect. It doesn’t have anything to do with elderly helping the “community” as the parent mentioned. It’s an interesting hypothesis being studied, but not in any way cut or dry.
crazydoggers 7y ago
Upsetting to see the downvoting on HN for providing scientific valid information in regard to conjecture. For more information on why group theory isn’t supported by the scientific community see the following: https://en.m.wikipedia.org/wiki/Group_selection https://en.m.wikipedia.org/wiki/Group_selection https://en.m.wikipedia.org/wiki/Kin_selection https://en.m.wikipedia.org/wiki/Kin_selection https://en.m.wikipedia.org/wiki/Evolutionarily_stable_strategy https://en.m.wikipedia.org/wiki/Evolutionarily_stable_strate...
- lukebitts 7y ago
  I don't think you were downvoted for providing scientific valid information in regard to conjecture. My best guess is that you were downvoted for calling something nonsense without anything to back it up. Maybe using gentler language would have helped here.

deleted 7y ago

[deleted]

barry-cotter 7y ago

Grandmothers increase their offspring’s genetic impact, for daughters by increasing survival rates, for sons by increasing numbers of offspring. http://en.wikipedia.org/wiki/Grandmother_hypothesis http://en.wikipedia.org/wiki/Grandmother_hypothesis > The grandmother hypothesis is a hypothesis to explain the existence of menopause in human life history by identifying the adaptive value of extended kin networking. It builds on the previously postulated "mother hypothesis" which states that as mothers age, the costs of reproducing become greater, and energy devoted to those activities would be better spent helping her offspring in their reproductive efforts. It suggests that by redirecting their energy onto those of their offspring, grandmothers can better ensure the survival of their genes through younger generations.

bilbo0s 7y ago
That's a hypothesis. Again, reproduction is happening prior to any potential partner even knowing of a grandmother in many places in the animal kingdom. Even for humans actually. So you're subscribing to the more adaptationalist line of reasoning for the existence of menopause. Which is fine. But you should concede that fact. Many others might subscribe to any of the other hypotheses for reproductive senescence. I subscribe to the artifactualist line of reasoning. ie - people just started living too long, and our bodies adapted for a 20-40 year life span. But there are numerous other hypotheses out there, many of them every bit as plausible as my artifactualist hypothesis. I only subscribe to the artifactualist hypothesis because it is the hypothesis most in line with the theory of evolution.
- gowld 7y ago
  How long is too long? A woman is fertile through age 40 (and useful to care for offspring for another 10-20 years), a man is fertile through age 80 (and a genetically fit male would have valuable sperm long after his fitness showed in his phenotype). Why would our bodies adapt for a 20-40 year life span?
crazydoggers 7y ago
If the grandmother hypothesis is true, then you’re still talking kin selection effect via grandparents, which is very different than group selection. I concede that kin selection is very possible, but again, as this is an unproven hypothesis at the moment, still a matter of scientific debate, hence not really clear or obvious.

murkle 7y ago

Yes, interesting question. Some relevant research: https://www.earth.com/news/kids-benefit-grandmother-healthy/ https://www.earth.com/news/kids-benefit-grandmother-healthy/ Edit: and https://www.cam.ac.uk/research/news/the-importance-of-grandmothers-in-the-lives-of-their-grandchildren https://www.cam.ac.uk/research/news/the-importance-of-grandm... Edit2: and https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.160069 https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.1600...

isolli 7y ago

Actually this has been studied, establishing for instance the grandmother effect in pre-industrial Canada [0] ("women with mothers nearby had more and healthier children"). See [1] for more resources. Anecdotally, I can personally attest that having grandparents too far to help makes it a lot harder to raise our two young children - there will certainly not be a third one. [0] https://www.cbc.ca/news/canada/montreal/grandmother-effect-1.5016545 https://www.cbc.ca/news/canada/montreal/grandmother-effect-1... [1] http://sacha-engelhardt.feedsrss.com/ http://sacha-engelhardt.feedsrss.com/

crazydoggers 7y ago
Just to clarify, this would be a kin selection effect, not a group selection effect. It doesn’t have anything to do with elderly helping the “community” as the parent mentioned. It’s an interesting hypothesis being studied, but not in any way cut or dry.

crazydoggers 7y ago

Upsetting to see the downvoting on HN for providing scientific valid information in regard to conjecture. For more information on why group theory isn’t supported by the scientific community see the following: https://en.m.wikipedia.org/wiki/Group_selection https://en.m.wikipedia.org/wiki/Group_selection https://en.m.wikipedia.org/wiki/Kin_selection https://en.m.wikipedia.org/wiki/Kin_selection https://en.m.wikipedia.org/wiki/Evolutionarily_stable_strategy https://en.m.wikipedia.org/wiki/Evolutionarily_stable_strate...

lukebitts 7y ago
I don't think you were downvoted for providing scientific valid information in regard to conjecture. My best guess is that you were downvoted for calling something nonsense without anything to back it up. Maybe using gentler language would have helped here.