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The Larger Brains of Humans Come with a Tragic Cost, Study Finds

imtringued 2y ago
The tragic cost being that the human body has not yet had the chance to adapt to lifespans of 80 years and beyond. I think this problem will disappear as more and more women delay child birth to their late 30s and 40s. Yes this means some women will not be fertile anymore by the time they are ready and have made the decision to have children, but the ones that remain fertile will pass on their genes and this will cause selective pressure towards longevity in humans.
- RandomThoughts3 2y ago
  Late age fertility and longevity is not the same thing.
  - daniel-thompson 2y ago
    yet
    - throwawaymeta01 2y ago
      if you start having kids earlier, you will have more kids. if so, wont those be more represented in the population and just stablize to closer to where we are today than otherwise?
- yieldcrv 2y ago
  1) What. You’re just selecting for fertility
  - kjkjadksj 2y ago
    Yeah. What might actually work on the other hand is having people donate their gametes as soon as they are fertile, freeze them, and depending on how they age over decades, use those known good gametes in ivf surrogates. Of course that’s not realistic to implement for many reasons and should probably be left for sci fi novels.
    - yieldcrv 2y ago
      Dont need that cop out disclaimer, I’m down for the possibility of this. Not for the older mom selection, just for the prerequisites that more women freeze their eggs when first fertile as opposed to a treating it as a failure mode when they're 30+ and have less viable eggs to start working with. Then that comes with the enhanced choice of selection.
  - Wytwwww 2y ago
    Isn't having children at an older age associated with a significantly higher rate of genetic mutations? Wouldn't that "speed up" evolution (for better or for worse)?
  - 1659447091 2y ago
    *not an expert here, and generally prefer computers to biology, but my reasoning would be, yes you are selecting for fertility but also as the parent said: > The tragic cost being that the human body has not yet had the chance to adapt to lifespans of 80 years and beyond. > I think this problem will disappear as more and more women delay child birth to their late 30s and 40s. Those who have adapted a human body with long age fertility and a body that can hold up to childbirth over a longer time, probably has other genes that allowed for the body to adapt to the longer lifespans, thus passing them on. Also adding on the mutation sibling comment
    - yieldcrv 2y ago
      My issue is that’s so much further of a stretch than other possible approaches Fertility is primarily a function of how many eggs the woman started with, and the interval of periods which shed an egg. Further down the rank are viable eggs remaining - if all weren't shed to begin with due to irregular periods at a faster frequency than a monthly cycle - and finally the ability to incubate without miscarriage which is the only unquantifiable part, which also involved the man’s sperm that was selected. Although since a different man can always be selected, I cant try to reframe this as an issue to include older men since its not much of an issue and younger men exist. You’re proposing to use this lowly ranked incubation aspect, all to assume some other genetics for longevity are passed on, while introducing mutations from gamete deterioration. Amusing to me, seems like too much energy to attempt this versus some other selective pressure or versus a remedy to a current generation’s mental deterioration.
AnthonBerg 2y ago
The paper: The uniqueness of human vulnerability to brain aging in great ape evolution by Sam Vickery and others (Science Advances issue 10, 2024) https://www.science.org/doi/10.1126/sciadv.ado2733 https://www.science.org/doi/10.1126/sciadv.ado2733 (I’m super curious as to why those sciencey feed-site thingies almost never say what paper it is. Just “a study published in Bla”. Kind of hidden? It’s…deeply weird to me. Curious about the incentives. Or if it’s simply a culture of sorts.)
yieldcrv 2y ago
Fix it

The tragic cost being that the human body has not yet had the chance to adapt to lifespans of 80 years and beyond. I think this problem will disappear as more and more women delay child birth to their late 30s and 40s. Yes this means some women will not be fertile anymore by the time they are ready and have made the decision to have children, but the ones that remain fertile will pass on their genes and this will cause selective pressure towards longevity in humans.

RandomThoughts3 2y ago
Late age fertility and longevity is not the same thing.
- daniel-thompson 2y ago
  yet
  - throwawaymeta01 2y ago
    if you start having kids earlier, you will have more kids. if so, wont those be more represented in the population and just stablize to closer to where we are today than otherwise?
yieldcrv 2y ago
1) What. You’re just selecting for fertility
- kjkjadksj 2y ago
  Yeah. What might actually work on the other hand is having people donate their gametes as soon as they are fertile, freeze them, and depending on how they age over decades, use those known good gametes in ivf surrogates. Of course that’s not realistic to implement for many reasons and should probably be left for sci fi novels.
  - yieldcrv 2y ago
    Dont need that cop out disclaimer, I’m down for the possibility of this. Not for the older mom selection, just for the prerequisites that more women freeze their eggs when first fertile as opposed to a treating it as a failure mode when they're 30+ and have less viable eggs to start working with. Then that comes with the enhanced choice of selection.
- Wytwwww 2y ago
  Isn't having children at an older age associated with a significantly higher rate of genetic mutations? Wouldn't that "speed up" evolution (for better or for worse)?
- 1659447091 2y ago
  *not an expert here, and generally prefer computers to biology, but my reasoning would be, yes you are selecting for fertility but also as the parent said: > The tragic cost being that the human body has not yet had the chance to adapt to lifespans of 80 years and beyond. > I think this problem will disappear as more and more women delay child birth to their late 30s and 40s. Those who have adapted a human body with long age fertility and a body that can hold up to childbirth over a longer time, probably has other genes that allowed for the body to adapt to the longer lifespans, thus passing them on. Also adding on the mutation sibling comment
  - yieldcrv 2y ago
    My issue is that’s so much further of a stretch than other possible approaches Fertility is primarily a function of how many eggs the woman started with, and the interval of periods which shed an egg. Further down the rank are viable eggs remaining - if all weren't shed to begin with due to irregular periods at a faster frequency than a monthly cycle - and finally the ability to incubate without miscarriage which is the only unquantifiable part, which also involved the man’s sperm that was selected. Although since a different man can always be selected, I cant try to reframe this as an issue to include older men since its not much of an issue and younger men exist. You’re proposing to use this lowly ranked incubation aspect, all to assume some other genetics for longevity are passed on, while introducing mutations from gamete deterioration. Amusing to me, seems like too much energy to attempt this versus some other selective pressure or versus a remedy to a current generation’s mental deterioration.

AnthonBerg 2y ago

The paper: The uniqueness of human vulnerability to brain aging in great ape evolution by Sam Vickery and others (Science Advances issue 10, 2024) https://www.science.org/doi/10.1126/sciadv.ado2733 https://www.science.org/doi/10.1126/sciadv.ado2733 (I’m super curious as to why those sciencey feed-site thingies almost never say what paper it is. Just “a study published in Bla”. Kind of hidden? It’s…deeply weird to me. Curious about the incentives. Or if it’s simply a culture of sorts.)

yieldcrv 2y ago

Fix it