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> IANAdoctor/biologist but i assume diseases that tend to strike after child bearing age have less negative selection pressure than other diseases. It gets eve

by R0b0t1 5y ago

> IANAdoctor/biologist but i assume diseases that tend to strike after child bearing age have less negative selection pressure than other diseases. It gets even better: there is selective pressure for adults that have borne children to die so that their children can procreate. First noted in pea plants that send a chemical signal to kill themselves up from the pod, can be extended to animals in things like cancer rates.

mtts 5y ago
Except that humans are not pea plants and having grandparents play an active role in child rearing significantly improves the survival odds for their grandchildren (who carry a quarter of their genes).
nindalf 5y ago
Humans aren’t peas. Pea grandparents don’t help out in child rearing but human grandparents do. There is no indication that humans face selective pressure to die early.
- carlmr 5y ago
  >There is no indication that humans face selective pressure to die early. While I do agree that pea plants are different, human grandparents may help in child rearing, but they may also consume time and energy for care. We're social animals that would not kill our own grandparents for having more food/time available. But nature might find it's useful for procreation if they don't live too long. Elderly care is a huge time/energy sink. And longevity makes the input/output unfavorable in a lot of cases. If you're in an environment like our ancestors where food was most of the time scarce, then that adds weight to this equation.
- R0b0t1 5y ago
  There is evidence that earlier death can help animals, so it is appropriate to extend it to all animals barring evidence to the contrary. Long lived, already procreated animals limit the amount of evolution that can take place by drawing out the time between procreation events. So if you have 2 species, one which dies earlier but has more generations, you expect them to outcompete a longer lived species.

by R0b0t1 5y ago

mtts 5y ago

Except that humans are not pea plants and having grandparents play an active role in child rearing significantly improves the survival odds for their grandchildren (who carry a quarter of their genes).

nindalf 5y ago

Humans aren’t peas. Pea grandparents don’t help out in child rearing but human grandparents do. There is no indication that humans face selective pressure to die early.

carlmr 5y ago
>There is no indication that humans face selective pressure to die early. While I do agree that pea plants are different, human grandparents may help in child rearing, but they may also consume time and energy for care. We're social animals that would not kill our own grandparents for having more food/time available. But nature might find it's useful for procreation if they don't live too long. Elderly care is a huge time/energy sink. And longevity makes the input/output unfavorable in a lot of cases. If you're in an environment like our ancestors where food was most of the time scarce, then that adds weight to this equation.
R0b0t1 5y ago
There is evidence that earlier death can help animals, so it is appropriate to extend it to all animals barring evidence to the contrary. Long lived, already procreated animals limit the amount of evolution that can take place by drawing out the time between procreation events. So if you have 2 species, one which dies earlier but has more generations, you expect them to outcompete a longer lived species.