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> giving birth and breastfeeding being a very costly event with very real risks for almost all women. Natural selection suggests that women who find giving bir

by klipt 5y ago

> giving birth and breastfeeding being a very costly event with very real risks for almost all women. Natural selection suggests that women who find giving birth and breastfeeding more difficult than average women, will die off over time and be replaced by the descendents of those women who found it easier than average women.

lotsofpulp 5y ago
Natural selection does not work in timescales relevant to discussions about our civilizations.
- klipt 5y ago
  It works faster on cultures than on genes, of course. That's called "memetic evolution".
GioM 5y ago
If you consider only the selection pressure from the mother’s side then yes that is the case. However you must consider that the mother and the father are in an arms race with respect to the carrying capacity of the mother. The selection pressure from the father will always tend towards an offspring that is the maximum capacity at which the mother can bear.
- FooBarBizBazz 5y ago
  That's true only if the selection pressure on individual children favors largeness, right? On an island or without as much nutrition, it might be an advantage to be smaller, since you could get by on less food.
  - klipt 5y ago
    That's a prisoner's dilemma situation. As a group, smaller islanders are less likely to run out of food (the cooperation strategy). But as an individual, a bigger islander can beat up the smaller ones and take their food (the defection strategy). Of course if everyone defects, the group as a whole is worse off.
    - FooBarBizBazz 5y ago
      I dunno. If they really were trapped in a Prisoner's Dilemma, then the equilibrium would be that they get big, I think (unless there's a "repeated games" angle here). Yet what we actually observe, of species that get isolated on islands, is that they do get small.
- klipt 5y ago
  If that's the case then women who have an easier time having kids than average will be more desirable mates and attract higher quality men than women who have a harder time having kids than average.

by klipt 5y ago

lotsofpulp 5y ago

Natural selection does not work in timescales relevant to discussions about our civilizations.

klipt 5y ago
It works faster on cultures than on genes, of course. That's called "memetic evolution".

GioM 5y ago

If you consider only the selection pressure from the mother’s side then yes that is the case. However you must consider that the mother and the father are in an arms race with respect to the carrying capacity of the mother. The selection pressure from the father will always tend towards an offspring that is the maximum capacity at which the mother can bear.

FooBarBizBazz 5y ago
That's true only if the selection pressure on individual children favors largeness, right? On an island or without as much nutrition, it might be an advantage to be smaller, since you could get by on less food.
- klipt 5y ago
  That's a prisoner's dilemma situation. As a group, smaller islanders are less likely to run out of food (the cooperation strategy). But as an individual, a bigger islander can beat up the smaller ones and take their food (the defection strategy). Of course if everyone defects, the group as a whole is worse off.
  - FooBarBizBazz 5y ago
    I dunno. If they really were trapped in a Prisoner's Dilemma, then the equilibrium would be that they get big, I think (unless there's a "repeated games" angle here). Yet what we actually observe, of species that get isolated on islands, is that they do get small.
klipt 5y ago
If that's the case then women who have an easier time having kids than average will be more desirable mates and attract higher quality men than women who have a harder time having kids than average.