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It doesn’t make tremendous evolutionary sense to have these creatures that can’t even keep themselves alive and require an enormous investment of time on the pa

by pj 17y ago

It doesn’t make tremendous evolutionary sense to have these creatures that can’t even keep themselves alive and require an enormous investment of time on the part of adults. That period of dependence is longer for us than it is for any other species, and historically that period has become longer and longer. The evolutionary answer seems to be that there is a tradeoff between the ability to learn and imagine — which is our great evolutionary advantage as a species — and our ability to apply what we’ve learned and put it to use. So one of the ideas in the book is that children are like the R&D department of the human species. They’re the ones who are always learning about the world. This couldn't be farther from the truth, well... perhaps it could, but it is not the truth, nonetheless. The evolutionary reason that human children are so helpless at birth is because the hole through the female pelvis got smaller to support walking on two legs. This need for a stronger pelvis, combined with the relatively larger head of the human baby, prevented full development of the baby before birth. All human babies are therefore born premature. Other similarly sized babies throughout the animal kingdom take a year or more to be born and they are born able to walk and care for themselves.

jerf 17y ago
"The evolutionary reason..." Whoa, whoa, whoa. The evolutionary reason? That's not how it works. If elongated childhoods wasn't worth walking on two legs, it would have gotten selected out. The two issues, and a complex of others, can't be considered in isolation. Moreover, our "learning" phase isn't just delayed by a month or three months, we have childhoods that are ten years or more delayed. That isn't explained by any conceivable birth issues. The usual explanation is that we've traded instincts for the ability to learn the behaviors in a non-instinctual manner, which is inherently slower, but far more flexible.... but that's hardly "the" reason either.
- pj 17y ago
  Perhaps I should have said, "A better evolutionary explanation for helpless babies is..." Babies began being born prematurely after humans started walking upright. It was after these helpless babies were born that we evolved the ability to care for them. This may have compounded the issue, because perhaps intelligence was required to care for them. Thus the babies were born with even larger heads and on and on. Babies can't reproduce, but if the organism does not live long enough to reproduce, the babies aren't born at all, so walking upright is more important than being born able to walk and care for themselves. Some hypotheses suggest that walking upright allowed us to cool our heads and resist heat stroke when trees disappeared in Africa. Large brains were actually radiators disipating heat, and containers for backup neurons when some failed due to running down prey and the extreme heat of desert climates. Thus, babies born with larger brains had more heat resistance and backup neurons, thus more likely to reach fertility. It is my prediction, that in the future, all babies will be born by c-section.
albertcardona 17y ago
You are overlooking the serendipitous positive use of what otherwise would be negative traits, which is pretty much the origin of complex traits. In other words, that babies got to grow without much hardwired control of their own bodies (and that includes thoughts) provided the opportunity for humans to grow into distinct behavioral patterns (i.e. exercise creativity), and to free themselves from what the genes predispose and then be open for what the culture demands and imprints. Think about it: the ability to learn so much and about such breadth of subjects could, perhaps, have been made possible by the early birth imposed by pelvic changes related to upright walking. Chimpanzee babies only get one month of flexible, learn-it-all minds.

by pj 17y ago

jerf 17y ago

"The evolutionary reason..." Whoa, whoa, whoa. The evolutionary reason? That's not how it works. If elongated childhoods wasn't worth walking on two legs, it would have gotten selected out. The two issues, and a complex of others, can't be considered in isolation. Moreover, our "learning" phase isn't just delayed by a month or three months, we have childhoods that are ten years or more delayed. That isn't explained by any conceivable birth issues. The usual explanation is that we've traded instincts for the ability to learn the behaviors in a non-instinctual manner, which is inherently slower, but far more flexible.... but that's hardly "the" reason either.

pj 17y ago
Perhaps I should have said, "A better evolutionary explanation for helpless babies is..." Babies began being born prematurely after humans started walking upright. It was after these helpless babies were born that we evolved the ability to care for them. This may have compounded the issue, because perhaps intelligence was required to care for them. Thus the babies were born with even larger heads and on and on. Babies can't reproduce, but if the organism does not live long enough to reproduce, the babies aren't born at all, so walking upright is more important than being born able to walk and care for themselves. Some hypotheses suggest that walking upright allowed us to cool our heads and resist heat stroke when trees disappeared in Africa. Large brains were actually radiators disipating heat, and containers for backup neurons when some failed due to running down prey and the extreme heat of desert climates. Thus, babies born with larger brains had more heat resistance and backup neurons, thus more likely to reach fertility. It is my prediction, that in the future, all babies will be born by c-section.

albertcardona 17y ago

You are overlooking the serendipitous positive use of what otherwise would be negative traits, which is pretty much the origin of complex traits. In other words, that babies got to grow without much hardwired control of their own bodies (and that includes thoughts) provided the opportunity for humans to grow into distinct behavioral patterns (i.e. exercise creativity), and to free themselves from what the genes predispose and then be open for what the culture demands and imprints. Think about it: the ability to learn so much and about such breadth of subjects could, perhaps, have been made possible by the early birth imposed by pelvic changes related to upright walking. Chimpanzee babies only get one month of flexible, learn-it-all minds.