The Mammal That Pair-Bonds Like A Bird

Since our ancestors lived in the trees, we have undergone two adaptations, both of which were an understandable response to evolutionary pressures but whose combination is really quite a bad idea. These two adaptations are the upright posture and the big brain. The pelvic changes of the first adaptation have made it very difficult to birth infants with the oversized cranium of the other. What to do? Pop them out before the head gets big enough to kill the mother; that is, big enough to kill the mother every time.

All human babies are therefore born “prematurely”, and always will be. No other mammalian young are born so helpless, unless we count the marsupials, whose joeys are “born” halfway through their development and finish it in the pouch. In our case, we are born halfway through our development, which we finish only after college, and have no pouch to crawl into. This mandates intensive parental care, more intensive than the mother alone can, in a state of nature, provide. Given that the evolution of the big brain is fairly recent, we may wonder whether the transformation of our mammalian instincts to serve this thoroughly anomalous human family structure is in fact complete.

For we are almost unique in the mammalian world. Almost the only exemplars of what is supposed by some to be the “natural” pattern for mankind – that is, mated pairs living in communities of other mated pairs – are avian species. This has much to do with the portability of food; there is not that much a male grazer can do specifically for his own offspring. And wherever there is paternal investment, there is at least approximate monogamy. Now, not only are there very few monogamous mammals, there are few mammals that maintain long-term intergenerational bonds at all. There are virtually no mammals that integrate males into “families”, and none at all apart from ourselves that cultivate such families within the framework of intensely personalised community relationships. In short, Homo sapiens is a mammal that behaves somewhat like a bird, and is commanded by his various religions to act even more like a bird. What those religions fail to realise is that what at least some of these avian species actually do is to form pair-bonds and then cheat on their partners, but that is a story for another day.

Posted on April 3, 2009 at 10:37 by Hugo Grinebiter · Permalink

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