For a few days I've struggled with why in the world newborn babies in the Animal Kingdom are so much more agile, mobile, and physically capable at birth than my little one. Our supposed closest relative, the chimpanzee, can nimbly swing up and cling to his mother as she travels through the tree tops. Yet my "more advanced" species-boy is just now, at 4.5 months old, sitting up with assistance and topples over if left unattended. What in the world??So I found this article that outlines the theory that because of our big brains, there's more developing to do outside of the womb. Essentially, if I'm understanding it correctly, humans are born early so that they can fit that huge noggin through the birth canal. But don't you think that consistent early delivery would be fatal to infants? I mean, just a hundred years ago we didn't have the technology to keep premature babies alive.
Anyway, if you have a minute, read it and let me know what you think. And yes, this means you, Mikey. :)
2 comments:
Hey, it's one of my favorite websites, linked on one of my favorite websites.
I'd like to point out that in an evolutionary context, humans are not "more evolved" or "more advanced" than chimps -- there is no such thing in evolutionary theory as some huge hierarchy of being going from sea slugs to humans. The only measure is how well a specific organism is adapted to its specific environment.
For instance, sea slugs are spectacularly "more advanced" than humans when it comes to living a mile beneath the ocean surface and surviving on goop that collects on rocks. See what I mean? (That said, James is way more advanced than that chimp when it comes to being cute.)
To answer your question about infant mortality, it has a lot to do with another difference between chimps and humans: as a species, we tend to live in much larger and more interconnected societies, clans, tribes, etc., which are able to provide support for our wimp-ass babies. In fact, greater dependence on social grids like a tribe or clan or Medicaid may have actually been influenced by our increasingly needy babies. Hey, there's another hypothesis!
But also, infant mortality rates WERE really huge not long ago, and have always been large. People used to have loads of kids and lose most of them. The evolutionary benefit of having big brains balanced with the detriment of increased infant death. If it weren't for those pesky narrow birth canals so long ago, it would have balanced closer to the big-head end of the spectrum and we'd probably all look like space aliens right now.
Wee, isn't science weird?
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