4 ms·

I find the grandparents hypothesis compelling at first glance but it sort of begs the question, why don't we live indefinitely in the first place? There are obv

I find the grandparents hypothesis compelling at first glance but it sort of begs the question, why don't we live indefinitely in the first place? There are obvious answers, we make tradeoffs to improve performance early in life at the expense of long term function, but it doesn't seem like the reproductive benefits of caring for a grandchild that only shares a 1/4 of your DNA necessarily tips the scales of selection towards longevity. Especially when, in theory, men remain fertile their entire lives and thus there should have always been some selection for longer life spans. You would expect the reproductive benefits of a 70 year old caring for their own child might be at least comparable to 70 year old caring for a grandchild.

lcnPylGDnU4H9OF 2y ago
> why don't we live indefinitely in the first place? It doesn’t seem to be necessary for the survival of our genes. > You would expect the reproductive benefits of a 70 year old caring for their own child might be at least comparable to 70 year old caring for a grandchild. They’re competing with 20-30 year-olds with better physical fitness for a mate. This would be relevant for ~99% of human existence even if it’s not totally relevant today.
WalterBright 2y ago
why don't we live indefinitely in the first place? 1. need to make room for the young, ecosystems are not unlimited 2. we accumulate parasites and diseases as we live. Dying kills them off, too 3. much slower evolution, implying losing ground compared with quickly evolving competitors
thrance 2y ago
Members of some species take care of the children of others, as well as theirs (Orcas come to mind, humans too if course). There is an advantage in helping others with similar DNA than you, because they will reciprocate.
EdwardDiego 2y ago
Obviously because Tree-of-Life didn't survive on Earth, so we could never achieve our final form. https://en.wikipedia.org/wiki/Pak_Protector https://en.wikipedia.org/wiki/Pak_Protector

lcnPylGDnU4H9OF 2y ago

> why don't we live indefinitely in the first place? It doesn’t seem to be necessary for the survival of our genes. > You would expect the reproductive benefits of a 70 year old caring for their own child might be at least comparable to 70 year old caring for a grandchild. They’re competing with 20-30 year-olds with better physical fitness for a mate. This would be relevant for ~99% of human existence even if it’s not totally relevant today.

WalterBright 2y ago

why don't we live indefinitely in the first place? 1. need to make room for the young, ecosystems are not unlimited 2. we accumulate parasites and diseases as we live. Dying kills them off, too 3. much slower evolution, implying losing ground compared with quickly evolving competitors

thrance 2y ago

Members of some species take care of the children of others, as well as theirs (Orcas come to mind, humans too if course). There is an advantage in helping others with similar DNA than you, because they will reciprocate.

EdwardDiego 2y ago

Obviously because Tree-of-Life didn't survive on Earth, so we could never achieve our final form. https://en.wikipedia.org/wiki/Pak_Protector https://en.wikipedia.org/wiki/Pak_Protector