What is \"human\"? (Evolution)

by dhw, Saturday, October 17, 2009, 17:46 (5514 days ago)

David (under "Evolution"): The expectation was that the common ancestor was more ape-like, following Darwin's suppositions. Ardi is more 'advanced' than was expected. The common ancestor may be further back than 6 million years with this finding about Ardi.-I don't really know where the 6 million years came from in the first place. I find all such dates pretty unconvincing, but if they have to be put back a million or ten million years, that still doesn't invalidate (or, of course, confirm)Darwin's "ape-like" theory. However, the more I think about it, the more nebulous this whole concept of ape/human becomes. Hence the new thread.-What constitutes "human"? David writes: "the brain increase in size was one of the last things to happen in the evolutionary development of humans." For me, it's the brain and everything that's associated with it that goes to make up our humanity: the almost infinitely more refined consciousness, language, inventiveness etc. Changes to the pelvis or the limbs or the feet, hands or teeth don't seem to me to make a major distinction between human and ape. In terms of molecular biology, we can apparently be classified alongside chimps as homininae, whereas orangutans (ponginae) are in a different subfamily even though they're also apes. So in that context an orangutan is more distinct from chimps than we are!-If we go back to Ardi, she may be more advanced than was expected, but advanced in what way? Does primitive bipedalism really make her more human? If we suppose, say, that changes in the vegetation led to certain anthropoids taking to the ground and walking upright ... or alternatively to certain anthropoids moving from the ground to the trees ... no matter what developments took place in the anatomy, without the enlarged brain wouldn't we still see them as more ape than human? -One theory (I can't remember where I read it) is that bipedalism freed the hands, the hands began to use tools, and the brain grew larger as a result of the extra mental activities involved. This suggests that the thought came before the enlargement, and raises the questions: where do thoughts come from and how can they enlarge the brain? The alternative would be how does an enlarged brain create thought, and if that is the way it happened, why did the brain get bigger in the first place? Of course it did get bigger, and we're here to prove it, but I'm not sure if we need a palaeoanthropologist, a neuroscientist, or a philosopher to sort out how it happened, and to tell us what "human" actually means.

What is \"human\"?

by David Turell @, Saturday, October 17, 2009, 20:10 (5514 days ago) @ dhw

One theory (I can't remember where I read it) is that bipedalism freed the hands, the hands began to use tools, and the brain grew larger as a result of the extra mental activities involved. -Our bigger brain requires much more energy than a smaller brain. It is just as possible, perhaps even more so, that the hands provided better energy supply and allowed the brain to enlarge.-
> but I'm not sure if we need a palaeoanthropologist, a neuroscientist, or a philosopher to sort out how it happened, and to tell us what "human" actually means.-Perhaps all of them: by definition to be human is to be us and compare everything else to us.-John McCrone in, "The Ape that Spoke", 1991, defines human speech as the dividing line between us and all other animals (pg.48). We think in words.To have speech, the palate has to have the palate to arch up and the larynx has to drop to lower levels than in the ape. As a result an epiglottis has to appear to act as a trap door to protect the larynx and the trachea from food and water, which is supposed to go down the esophagus.-So that is a major difference. The skeletons are very different, because of bipedalism, and the giant infant head reqires a very convoluted birth canal. So in brief, we are skeletally different and mentally different and I still maintain different in kind, not degree.

What is \"human\"?

by David Turell @, Sunday, October 18, 2009, 14:29 (5514 days ago) @ dhw


> If we go back to Ardi, she may be more advanced than was expected, but advanced in what way? Does primitive bipedalism really make her more human? If we suppose, say, that changes in the vegetation led to certain anthropoids taking to the ground and walking upright ... or alternatively to certain anthropoids moving from the ground to the trees ... no matter what developments took place in the anatomy, without the enlarged brain wouldn't we still see them as more ape than human? -
The following article of opinion struggles to defend Darwin. No need to. Some ape-like ancestor of apes AND humans is back in the mists of time. The real issue is what will we really find: 1) an ape that has surprisingly hominin features, or 2) an ape that is quite ape-like with little trace of hominin for the future. At this juncture, no one knows, but ape-like it will be. The way the common ancestor will be identified (fossils don't come labeled as in the museum)is that there will be some anatomic mixture that gives a hint of future features.-http://blogs.sciencemag.org/origins/

What is \"human\"?

by dhw, Monday, October 19, 2009, 12:28 (5513 days ago) @ David Turell

David has referred us to an article by Ann Gibbons, who clears up some of the misunderstandings that have arisen over the original report on Ardi. The fact that Ardi was not like a chimpanzee has been distorted into claims that humans did not descend from apes (or ape-like ancestors). "Not like a chimpanzee" does not mean "not like an ape". After all, the oldest chimp fossils ever found only go back half a million years, whereas primates are believed to go back about 50 million. However, David points out that at this juncture no-one knows what the "common ancestor" will be like, and ... a great line ... "fossils don't come labeled as in the museum".-I would go a lot further. I don't think there is any way in which we could ever identify "THE" common ancestor. We may find fossils of all kinds of extinct ape-like species, with all kinds of primitive "human" traits, but everything that we find will have descended from something else. All species must have common ancestors, and since we have absolutely no way of knowing what has NOT been discovered, we will still be confined to speculation. I see this as yet another instance of language creating its own reality. We use expressions like "common ancestor" and the old favourite "missing link", and somehow these create a pattern, almost an authenticity of their own ... as if these things are bound to exist because we have words for them. My guess is that there are lots and lots of missing links. -You have also referred us to John McCrone, who argues that human speech is the dividing line between us and all other animals. The physiological changes necessary to allow human speech certainly mark yet another difference, but of course other animals also have a larynx and an epiglottis, and also make sounds with meaning. Our languages are almost infinitely more complex, but once again "more" = degree. I would say the new form/position of palate and larynx, like the altered pelvis and birth canal, are variations on existing structures and therefore not "different in kind". But, as I've said before, this only matters if one wants to argue for special, Genesis-type creation as opposed to evolution. I do think we are special, and language is a crucial part of our "human-ness", but so too are cave paintings, mastery of fire, the invention of the wheel, none of which are connected with speech. For me, it comes down to human intelligence, the seat of which is the brain, and this seems to have expanded very rapidly in homo erectus from chimp-size to roughly our size. Maybe homo erectus is the guy that holds the key.

What is \"human\"?

by xeno6696 @, Sonoran Desert, Tuesday, October 20, 2009, 05:03 (5512 days ago) @ dhw

One theory (I can't remember where I read it) is that bipedalism freed the hands, the hands began to use tools, and the brain grew larger as a result of the extra mental activities involved. This suggests that the thought came before the enlargement, and raises the questions: where do thoughts come from and how can they enlarge the brain? The alternative would be how does an enlarged brain create thought, and if that is the way it happened, why did the brain get bigger in the first place? Of course it did get bigger, and we're here to prove it, but I'm not sure if we need a palaeoanthropologist, a neuroscientist, or a philosopher to sort out how it happened, and to tell us what "human" actually means.-My eyes shoot open. I can't see anything yet because my contacts are dry and my vision is blurry.-*blink* *blink* *blink*-Squinting I lean up slowly and quietly... if I disturb the dog he'll think its breakfast time. Six a.m.-F--k. My alarm clock goes off in half an hour. -I lean back and take a deep breath. If I go back to sleep now, I'll be 3x as tired. -I close my eyes anyway, driven by my enjoyment of sleep directly sloughing off my own observation that I'm going to be more tired.-After waking up, feeding the animals, slogging down a quart of water and a pint of coffee, I stare for a bit at this interesting post by dhw. I put my computer into hibernate.-***-8 hours later I come home. After working a bit more on a program, I set it down and consider a bit more on what it means to be a human. Some might say that being a human means I can reason. That is something taken for granted since Plato. But that's not all that makes me human. You see, in my grand apostasy of my youth... I took all these things for granted; there's something much more relevant to being human than being able to reason. This thing was instilled in my in my 12 years split between martial arts and Soto Zen. -I take a deep breath and know I'm here... in the now. I lay back and think about how I can communicate the idea of being human without being too pedantic... and it hits me. I'll write about my morning, and then my afternoon. -My time spent studying my ancestor's old pagan path, though filled with blood, was also filled with a very human wisdom...
Man is a slippery and mercurial creature. Whatever he says he is--he isn't, and whatever he says he isn't--he is. -What makes us human is something that cannot be stated plainly. It isn't logic, it is that primal light that some would call "soul."

--
\"Why is it, Master, that ascetics fight with ascetics?\"

\"It is, brahmin, because of attachment to views, adherence to views, fixation on views, addiction to views, obsession with views, holding firmly to views that ascetics fight with ascetics.\"

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