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gravityeyelidsvia http://ift.tt/2lwGOZw:
Good question! Birth is really painful for humans because of how our specific evolution has made babies (and in some ways, how technology is actually continuing to remove specific pressures on baby morphology). For most mammals, birth is pretty painless unless something is wrong. Painful birth means injurious birth, often, and that’s not an adaptive strategy.
Human babies have absolutely ridiculously huge head sizes compared to other mammalian infants. It plays into a lot of how our reproduction works - human babies are very helpless when they’re born, compared to even other apes, because if they had more time to cook their heads would be too big to pass through the birth canal. As women get towards the end of pregnancy, ligaments in their hips structures actually loosen to allow for a wider range of movement so the head can get through.
I was reading something recently talking about how, with the advent of c-sections and other medical technology, babies are being born increasingly larger and with larger heads - without that technology, the baby and probably the mother would die in childbirth, effectively self-selecting the population against gestating babies past a size that can be born safely.
So really, it’s just us, not them.
(Your picture was not posted)
Good question! Birth is really painful for humans because of how our specific evolution has made babies (and in some ways, how technology is actually continuing to remove specific pressures on baby morphology). For most mammals, birth is pretty painless unless something is wrong. Painful birth means injurious birth, often, and that’s not an adaptive strategy.
Human babies have absolutely ridiculously huge head sizes compared to other mammalian infants. It plays into a lot of how our reproduction works - human babies are very helpless when they’re born, compared to even other apes, because if they had more time to cook their heads would be too big to pass through the birth canal. As women get towards the end of pregnancy, ligaments in their hips structures actually loosen to allow for a wider range of movement so the head can get through.
I was reading something recently talking about how, with the advent of c-sections and other medical technology, babies are being born increasingly larger and with larger heads - without that technology, the baby and probably the mother would die in childbirth, effectively self-selecting the population against gestating babies past a size that can be born safely.
So really, it’s just us, not them.
(Your picture was not posted)
