Human Hands More Primitive than Chimp Hands

  • metta

    Posts: 44725

    Jul 15, 2015 6:52 AM GMT
    Human Hands More Primitive than Chimp Hands
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    Jul 15, 2015 2:24 PM GMT
    But mightn't evolution have kept that structure purposely, and if so then it might not be quite correct to say it isn't as evolved but rather that specific evolutionary purposes were maintained during evolution? I've not studied this, just guessing.

    Swimming for instance. Yeah, monkeys and chimps can do it but they're not racing a front crawl. So they swing in trees better but we swim better. They can escape an enemy, we can escape an island.
    Most mammals are able to swim instinctively without training; a notable exception being the great apes. Humans are clearly able to become proficient swimmers with training; other great apes, however, have not been documented as swimmers beyond anecdotal reports. Chimpanzees, for example, are claimed to enjoy playing in water but not to swim. The unwillingness to swim is strong enough that it presumably played a role in the speciation of common chimpanzees and bonobos, which are geographically separated by the Congo River. Notably, this finding does not extend to all primates, as some monkey species, such as crab-eating macaques and proboscis monkeys, have been observed swimming underwater...

    ...This potential difference could also result, however, from physiological differences. Accordingly, a number of features of modern human physiology have been proposed as means by which humans, but not our closest relatives, are able to swim. These include: an infant swimming reflex, a diving reflex, voluntary breath-holding, and buoyancy provided by increased adipose tissue. However, these examples do not hold up well under scrutiny...

    ...Aquatic foods such as crocodiles, turtles, and fish have been implicated in the hominin diet as far back as 2 million years ago in Kenya. Essential fatty acids are high in fish; in particular, the omega-3 fatty acid docosahexaenoic acid (DHA) is much higher in fish than other dietary sources. These fatty acids are high in brain tissue and important to brain function. It has therefore been proposed that a near-water habitat and the harvesting of aquatic foods were important features of early Homo...

    So maybe it was our paddle-like hands, facilitating better swimming than narrower tree-climbing hands, which allowed us to hunt more efficiently in water, escape danger in water, and thereby to consume oils essential for brain development.
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    Jul 16, 2015 2:53 AM GMT

    Quint: You have city hands, Mr. Hooper. You been countin' money all your life.
    Hooper: All right, all right. Hey, I don't need this... I don't need this working-class-hero crap.