Hand<->Brain<----->Brain<->Hand?

Discussions unearthing human history including cultural anthropology, linguistics, etc.

Hand<->Brain<----->Brain<->Hand?

Postby çağla on October 10th, 2011, 7:39 am 

What I know little about human evolution is that we somehow became bipedals, this freed our hands and in a very long time, this helped our brains to develop and made us intelligent species.

I understand the crucial point here is to be a primate and have 'hands'.

I also understand that throwing and hitting something with another thing, without being taught is actually requires a primate to be highly evolved.

Do scientists have any idea that how having hands and using it changed our brain?

Do our "thumbs" have a special role in this? (Besides making us primates.)

If working with 'hands' is the only possible way leading our brain to evolve to use/make primitive tools, how did the relation between hand-brain start in the first place?

I think, I am making a mistake in thinking one is supposed to come first; this implies a sudden change as it would be impossible to guess in a process took so much time, but I thought there should be a reasoning to this. Is there?
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Re: Hand<->Brain<----->Brain<->Hand?

Postby Paralith on October 10th, 2011, 10:14 am 

The groundwork for hand-eye-mind coordination was really laid in the beginnings of the primate order.

Firstly, to have thumbs is a defining characteristic of all primates - every single one has them. Primates, unlike most mammals, also have forward facing eyes, and thus binocular vision, and larger visual cortices. Exactly what this suite of traits originally evolved to do is unclear - improved climbing and maneuverability? Well, squirrels are fantastic climbers and jumpers, with all the old mammalian hardware. Some people (and I lean this way) think it may be more to do with night time hunting of insects up in the trees. You will note that all the classic predators, mammalian and bird, have forward facing eyes. And how do those primates that are still nocturnal insect hunters grab their prey? With their face, their mouth, like other mammals? No. With their hands. They reach out and snatch! This is a big change between primates and their mammalian ancestors. To explore and to probe, other mammals use their face, their nose and their mouth. Primates can explore with their hands. And exploring with the hands involves much more hand-eye/mind coordination than does exploring with the face.

Of course, for most primates, the hands do double duty. Probes/manipulators, and locomotion. They still have to walk on those hands. Which places certain requirements on hands in terms of durability, strength and support. When you become bipedal, you lift those requirements. And please note that wording. Bipedalism most likely did not evolve in order to let us use our hands for other things. Once bipedalism was established for its own reasons, it allowed our hands to do, and become specialized for, other things. And for reference, bipedalism came on the scene at least 4.4 million years ago. The first identifiable stone tools show up around 2.6 million years ago. And, those first tools are quite primitive. If you train a chimp or a bonobo long enough, you can eventually get them to make tools that look quite similar. Stone tools don't take a significant step upwards in complexity until about 1.7 million years ago.

And as long as I've brought up chimps and bonobos making tools, keep in mind that great apes, some monkey species, and even some bird species naturally make and use tools. Obviously modern human tools are much more complex than what these animals make and use, but the rudimentary requirements for basic tool making exist in animals without bipedalism, and even without hands.

As to the causes of our increased intelligence, well - larger relative brain sizes and more complex tools do roughly correlate with each other in time, but that only makes it more difficult to know what direction the causal arrow goes. And as with the evolution of our hands in relation to bipedalism, having more dextrous hands may have allowed us to efficiently take advantage of lifestyles that required larger brains, but does that mean larger brains evolved specifically because of hands? That's probably just a matter of interpretation. Larger brains probably evolved for a myriad of reasons - if only because something that expensive better entail plenty of benefits - and better control of hands for making finer tools is probably in there somewhere.
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Re: Hand<->Brain<----->Brain<->Hand?

Postby neuro on October 10th, 2011, 11:02 am 

çağla wrote:I think, I am making a mistake in thinking one is supposed to come first; this implies a sudden change as it would be impossible to guess in a process took so much time, but I thought there should be a reasoning to this. Is there?

I believe you are perfectly right here.

Neither is supposed to come first.

I shall try to reason from an evolutionary standpoint.

Assume a dog happened to have longer fingers in its forepaw and a bone-muscle structure in them which allowed for more versatile and independent movements of the single fingers. It would probably do it no much good. The "mutation" or possible evolutionary change would not be selected for.

Assume now that it could also stand up for a relatively long time on its back limbs. Or just take a bear rather than a dog.

In this case the more versatile paw might be of some use. But it would not, and it would not be selected for, if it were not accompanioed by an extension of the cerebral area dedicated to elaborating motor programs with such paw, so that more sophisticated movements could be performed.

So, both changes would be selected for (or better the three changes: standing, more versatile bone-muscle structure and more sophisticated neuronal control) if they happened to occur concurrently (or possibly little by little, in small corresponding steps, such that each potential improvement is accompanied by concomitant improvement in the other related aspects).

I am no expert in comparative physiology, but I should bet that the sophistication of paw movements in bears be noticeably higher than in dogs (because the capability of standing up makes it potentially useful) and that the cerebral area dedicated to forepaw movements be similarly more expanded.

A similar argument can be raised above tongue and throat muscular versatility and control, the parallel increase in the area of the brain dedicated to the control of such musculature, and the possibility of emitting more varied sounds.

In a sense, a possible evolutionary advantage is not such if it does not happen to imply both an increased potential versatility and a more sophisticated neural control. Then, just give evolution a sufficient time, and both changes might well occur concomitantly.

Edit: I realize Paralith has given a much more relevant contribution, in the meanwhile. Still, I shall add these two cents of mine
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Re: Hand<->Brain<----->Brain<->Hand?

Postby Paralith on October 10th, 2011, 11:44 am 

neuro wrote:In this case the more versatile paw might be of some use. But it would not, and it would not be selected for, if it were not accompanioed by an extension of the cerebral area dedicated to elaborating motor programs with such paw, so that more sophisticated movements could be performed.


I would just like to emphasize one thing. The versatile paw might not be selected for, but it also might not be selected against. A dog that needs a less versatile, stronger paw for walking would probably suffer from having that versatile paw. But a dog that doesn't need that paw to be strong might still do alright with a versatile paw. Thus the versatile paw might hang out in the few individuals born with it, even without neurological changes. What neuro is saying that the versatile paw won't be selected for its versatility without those additional neurological changes. In essence, improved motor control is a package of morphology and neurology, not a single trait.
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Re: Hand<->Brain<----->Brain<->Hand?

Postby çağla on October 12th, 2011, 4:22 am 

Thank you for the responses. Sorry for the late reply.

What I understand to be the important points here are;

When thinking about evolution,

-there isn't a deterministic approach to any step in an understood process. I mean, I shouldn't think of a cause, as a reason to a conclusion.
-there are roughly 3 conditions for a step in evolutionary development in this case.
A change in a large scale in organism's physical qualities is needed; then if any possible sub-change(s) occur as a result of that change, if it’s selected for, it has to follow baby steps related to other aspects (benefits? Or again the same process in itself as a sub process?), which has to correspond to each side.

There is a high chance I made a mess of it.
----------------
Is it reasonable to assume that if there was any deterministic approach to any evolutionary step, life wouldn’t be this diverse on our planet?

Paralith, by “larger relative brain sizes and more complex tools do roughly correlate with each other in time”, do you mean it should have correlated more accurately or it’s enough to come to a conclusion, but implies other things also? (I liked the expression of “something that expensive”.)

Are primates and animals that make primitive tools considered as ‘evolved’ in the same way as us? Because as far as I understand, we are an anomaly? Or is it incorrect to look it that way?

Neuro, is it reasonable to think that brain –with its biological qualities as an organ different than any other organs in our body, I don’t mean the ones making us intelligent- played a role in this? Or is this a incorrect way to look at it?

[Another thing I understand –it’s just a sentiment- thinking about human development, we’ve evolved fast. The amount of time is enormous, but from a point, it seems a little time and it makes me inclined to see human more animal than usual. I don’t mean anything by this. It’s just fascinating.]
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Re: Hand<->Brain<----->Brain<->Hand?

Postby Paralith on October 12th, 2011, 10:36 am 

çağla wrote:Thank you for the responses. Sorry for the late reply.

What I understand to be the important points here are;

When thinking about evolution,

-there isn't a deterministic approach to any step in an understood process. I mean, I shouldn't think of a cause, as a reason to a conclusion.


I'm not entirely sure what you mean by deterministic. I understand a deterministic process to be one where, given the same inputs, the outputs will always be the same/predictable. It's not necessarily that evolution is not deterministic; only that there are such vast numbers of inputs that are so variable, it's highly unlikely you'll ever get the exact same set of inputs more than once. The species' current morphology and gene sequences, the mutations that happen to pop up, all the different aspects of the species' environment (used in the broadest sense of the word) and what selection pressures they put on the species, and exactly how these things change through time.

Though I should emphasize, before someone else does, that mutation is definitely a random process, and mutation is the ultimate source of evolutionary change and variation in organisms.

-there are roughly 3 conditions for a step in evolutionary development in this case.
A change in a large scale in organism's physical qualities is needed; then if any possible sub-change(s) occur as a result of that change, if it’s selected for, it has to follow baby steps related to other aspects (benefits? Or again the same process in itself as a sub process?), which has to correspond to each side.

There is a high chance I made a mess of it.



Haha, I wouldn't call it a mess. First I would point out that your use of the term "large scale" isn't really necessary. Sure, the evolution of bipedalism might seem like a large change, but during its evolution it probably also required slow baby steps. An organism is a highly complex machine where all the parts need to work harmoniously together to make a functioning individual. If you suddenly wrench one of those parts in a totally different direction, you could upset the whole system. And of course, all these terms about rates of change are relative. Something might change "quickly" relative to an evolutionary time scale, but we're still talking about hundreds of generations.

Secondly, every step has to either be most neutral (maybe not very beneficial but definitely not harmful) or beneficial, otherwise that step would have been selected out and lost. And steps that are mostly neutral are often lost due purely to chance, because they don't quickly spread to large portions of the population. If only one or a few individuals have the trait, it might happen due to random sampling alone that the trait just doesn't make it into the next generation. So I guess when it comes to (currently) neutral changes, evolution is much more probabilistic than deterministic. Of course, neutral/positive/negative are all relative to the environment. If the environment changes, what's neutral one day could become positive the next.

There is a chance you understood all this already, and I just did a poor job of understanding your comments.


Is it reasonable to assume that if there was any deterministic approach to any evolutionary step, life wouldn’t be this diverse on our planet?


I'm not sure, only because of how complex biological organisms really are. I'd imagine a highly complex deterministic system could still breed a great deal of diversity, but I'm not enough of a mathematician to be able to answer this with any certainty.

Paralith, by “larger relative brain sizes and more complex tools do roughly correlate with each other in time”, do you mean it should have correlated more accurately or it’s enough to come to a conclusion, but implies other things also? (I liked the expression of “something that expensive”.)


I mean that the historical data can be difficult to interpret. Yes, our brains got bigger AND our tools got more complex, but which change drove which? Or are both changes just the side effect of some other driving source of selection? Our timeline of the past, made using fossils and archaeological finds, has a lot of holes in it. It's not very precise. Just because you find evidence of A earlier than you find evidence of B, doesn't necessarily mean that A came first. You just might not have found earlier evidence of B yet.

Are primates and animals that make primitive tools considered as ‘evolved’ in the same way as us? Because as far as I understand, we are an anomaly? Or is it incorrect to look it that way?


We are and we are not an anomaly. You will find people who prefer to emphasize one side of this over the other; people who want to emphasize our similarities and continuities with other animals, and people who want to emphasize our differences and uniqueness from other animals. Both will tell you that the other side is an inappropriate way to look at things.

Let me put it this way. Every species that is alive on the planet today has been evolving for the exact same length of time. All of our lineages were born on this planet some 3 billion years ago, and have survived in some form or another until today. Every species alive today has its own long and varied history, and possesses a particular combination of features that no other living species shares with them. Yes, on the sliding scale of typical primate features, humans are often way off on one end of the scale. But many primates are extreme and unique compared to other primates in other ways. And humans are far more similar to other primates than they are to other groups of mammals, and far more similar to other mammals than they are to birds, reptiles, and insects, etc etc.

In biology in general, you might say anomalies are normal. There is a saying amongst biologists; "Nothing in biology is absolute." For almost every general pattern/trend/rule you may find, there is an exception somewhere. So, what is the "correct" perspective? It depends entirely on what you're trying to study, on what your ultimate question is. If your question is about differences, then focus on the differences. If your question is about similarities and continuities, then focus on those.

[Another thing I understand –it’s just a sentiment- thinking about human development, we’ve evolved fast. The amount of time is enormous, but from a point, it seems a little time and it makes me inclined to see human more animal than usual. I don’t mean anything by this. It’s just fascinating.]


Like I said above, speed is all relative. Though I don't have any hard numbers on this, in terms of rates of genetic change, I imagine that humans and their ancestors are comparable to many other species, past and present. Behaviorally, humans do seem to change very fast. In alteration of our environment, both in speed and scale, there are probably few species that can be said to compete with us.
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Re: Hand<->Brain<----->Brain<->Hand?

Postby çağla on October 13th, 2011, 6:57 am 

Paralith,

I try to repeat as much as I can, don’t forget that I have a language barrier. So sometimes, I guess, I use some words in their general meaning when it could imply a certain another thing in the context.

By “deterministic approach”, I meant to think about the explained steps in an evolutionary process by completing them to each other –without being aware of- in accordance to replace them in some sort of an order in a whole in my mind. We are inclined to link and complete, create patterns according to our general information of things. While trying to make inquiries on a certian subject, this can be a trap.

Also related to your statement about “questions”, this is exactly what I am trying to do. More than looking for certain answers, I am trying to understand what kind of questions should be asked to understand the way of inquiries and what can be known in a field I am interested in.

For example, I know that the two great questions in anthropology are “What can I know about the world?”, “How can I know about the world?”. But these are defining grand scale questions drawing of a field’s borders. Alas, to ask a real question to learn, you should know about a little in that field. So, what I little understand makes me weak when attempting to ask a question. And trying to learn to think about evolution is very difficult in a different way –even in a little scale-, because of the knowledge’s unique nature in linking a detail to whole.

So I try to make marks in my mind to learn. When I expressed the being bipedal as “a change in great scale” that was what I was doing. It wasn’t to emphasize it’s greatness, but to mark a begining in a process. Because you wrote something important to me -“…Bipedalism most likely did not evolve in order to let us use our hands for other things. ...”- that helped me realise something I understood before, but didn’t come to know as a way of approaching to understand an evolutionary step. Because while thinking, I “completed” that cause to be a reason to create a pattern that would reach a conclusion, without realising and naturally being confused, as it’s also obvious with the basic information and reasoning on the detail, which actually tells there is no cocnlusion of the sort.

Anyway, so neutral is probabilistic, because it is already contained/included as far as it becomes negative, which is selected against, and positive which is selected for with the environment and countless other changes “determining” which trait is going to stay and develop?

“We are and we are not an anomaly. You will find people who prefer to emphasize one side of this over the other; people who want to emphasize our similarities and continuities with other animals, and people who want to emphasize our differences and uniqueness from other animals. Both will tell you that the other side is an inappropriate way to look at things.”

I never thought of this way before. On a side note - with a frown on my face- it explains a lot.

I make the distinction from on the result of human alienating itself from nature, mostly its own, because of the things we invented to make our lives easy and comfortable. I don’t think there could be any clear distinction between us and animals under given certain circumstances. Take simple civilisation (Law, food-shelter providing) out from everyday life for a certain time, the time needed to go back to being an ‘animal’, is the same amount of time between two meals.

While using the word “anomaly”, I had in mind two things:

First the old perspective of “being the only animal that is aware of its awareness”. I think on the biggest picture of everything I perceive that as a “certain step” to all things. Think of something like Sagan’s steps. From learning to use fire, to learning to use of radio waves for example. The fact that an animal can evolve to think, developed to make an inquiry in the simplest sense has always been baffling to me Paralith. I cannot enough express my mixed emotions on this. Goose bumps.

Secondly, after reading about “vendian biota” –I hope I spelled it correctly- I was astounded by the fact that there might have been a completely different life evolved on our planet and couldn’t help but think if; Would it really be completely different? Would there be intelligent animals? Would they be primate too? And after countless questions, I thought as the odds are very low; negligible for intelligent life already in general, it could be seen as an anomaly.

“Yes, our brains got bigger AND our tools got more complex, but which change drove which? Or are both changes just the side effect of some other driving source of selection?”

May be because of my education, I really don’t know why, but I’ve always been inclined to think –as a hunch- that spatial understanding of any “form” or “shape” of everything around us could be the first source to this kind of development. This is also caused by an architect and an art historian –severely rejected by architects and hated by art historians in his time- who probably was born 150 years earlier in my opinion. Gottfried Semper. It’s out of our subject, but shortly he claimed that even the most complex architectural designs were born -long before any architectural thought was born- from the most primitive ways of ‘making’. Like knitting something from leaves... It just makes sense to me, in layman’s terms.
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Re: Hand<->Brain<----->Brain<->Hand?

Postby Paralith on October 13th, 2011, 7:54 pm 

çağla wrote:Paralith,

I try to repeat as much as I can, don’t forget that I have a language barrier. So sometimes, I guess, I use some words in their general meaning when it could imply a certain another thing in the context.

By “deterministic approach”, I meant to think about the explained steps in an evolutionary process by completing them to each other –without being aware of- in accordance to replace them in some sort of an order in a whole in my mind. We are inclined to link and complete, create patterns according to our general information of things. While trying to make inquiries on a certian subject, this can be a trap.

Also related to your statement about “questions”, this is exactly what I am trying to do. More than looking for certain answers, I am trying to understand what kind of questions should be asked to understand the way of inquiries and what can be known in a field I am interested in.

For example, I know that the two great questions in anthropology are “What can I know about the world?”, “How can I know about the world?”. But these are defining grand scale questions drawing of a field’s borders. Alas, to ask a real question to learn, you should know about a little in that field. So, what I little understand makes me weak when attempting to ask a question. And trying to learn to think about evolution is very difficult in a different way –even in a little scale-, because of the knowledge’s unique nature in linking a detail to whole.

So I try to make marks in my mind to learn. When I expressed the being bipedal as “a change in great scale” that was what I was doing. It wasn’t to emphasize it’s greatness, but to mark a begining in a process. Because you wrote something important to me -“…Bipedalism most likely did not evolve in order to let us use our hands for other things. ...”- that helped me realise something I understood before, but didn’t come to know as a way of approaching to understand an evolutionary step. Because while thinking, I “completed” that cause to be a reason to create a pattern that would reach a conclusion, without realising and naturally being confused, as it’s also obvious with the basic information and reasoning on the detail, which actually tells there is no cocnlusion of the sort.


Ah, I think I follow you now. Prior to this thread, you had taken a result of bipedalism (more fine motor control in hands) and thought this might actually be the cause of the bipedalism. If I'm understanding you correctly, of course. This is a common error, and something you have to wrap your mind around when you're studying evolution. Each step in a sequence of changes might not have been possible without the previous step; but that doesn't mean the previous step was made only in order to get to the next step.

Anyway, so neutral is probabilistic, because it is already contained/included as far as it becomes negative, which is selected against, and positive which is selected for with the environment and countless other changes “determining” which trait is going to stay and develop?


Yep, basically. It's really quite simple in theory. The difficulty comes in the practice, which is so often the case in biology. Simply quantifying the phrase "the selection pressures imposed by the environment" is a monumentally complex task that has so far only been done in the most simplified ways possible.

I never thought of this way before. On a side note - with a frown on my face- it explains a lot.


Yea. In the past few years I've been harshly criticized by each side for standing too close to the other side. I personally have swung back and forth as to which perspective is most important, only to realize that both are equally legitimate.

I make the distinction from on the result of human alienating itself from nature, mostly its own, because of the things we invented to make our lives easy and comfortable. I don’t think there could be any clear distinction between us and animals under given certain circumstances. Take simple civilisation (Law, food-shelter providing) out from everyday life for a certain time, the time needed to go back to being an ‘animal’, is the same amount of time between two meals.

While using the word “anomaly”, I had in mind two things:

First the old perspective of “being the only animal that is aware of its awareness”. I think on the biggest picture of everything I perceive that as a “certain step” to all things. Think of something like Sagan’s steps. From learning to use fire, to learning to use of radio waves for example. The fact that an animal can evolve to think, developed to make an inquiry in the simplest sense has always been baffling to me Paralith. I cannot enough express my mixed emotions on this. Goose bumps.


It's common for people to think of humans as somehow outside of, above, or alienated from nature. But, all the things we have done to modify our environment and our lives, we could never have done if it weren't for our nature, for our evolved biological capacities. And this ties in to your bafflement about the human brain. I admit, I sometimes feel the same way you do. The human brain just seems to be such a massively, incredibly complex thing, with such a range and variety of capabilities and possibilities. How could such a thing be selected for? But that's just it. If your brain can be said to have one single major function (other than making sure you body keeps running), it is to take in information from the world around it, and adjust our behavior accordingly. Flexibility. Adaptability, within one lifetime, within one moment.

As amazing as DNA is, it can't possibly hold enough information to 100% prepare you for everything you may or may not face in your life. And for organisms without flexible, learning brains, that's all they got. If you don't happen to have the right information in your DNA, you're toast. You can only hope that, in the process of making the next generation, mutations occur that manage to give your offspring better information. The rate of adjustment to environmental changes is strictly constrained by the rate at which you can reproduce. But that constraint is lifted if you have a flexible, adaptable brain.

This is especially valuable for large bodied animals like us with generation lengths of 20 to 25 years. The environment can change a LOT in 20 years! And, what is a better defense against a changing environment, than to take control of that environment, to stop it from changing in ways detrimental to you, and force it to change to suit you better? What more could selfish genes want, but the perfect environment that will always select for them and never against them? I say that what humans have done in the past ten thousand years is very natural, and is probably something we should expect anywhere life exists and has had a long enough time to evolve.

Secondly, after reading about “vendian biota” –I hope I spelled it correctly- I was astounded by the fact that there might have been a completely different life evolved on our planet and couldn’t help but think if; Would it really be completely different? Would there be intelligent animals? Would they be primate too? And after countless questions, I thought as the odds are very low; negligible for intelligent life already in general, it could be seen as an anomaly.


This really applies to any life that might appear - or has appeared - anywhere in the universe. Now, just before this I said we should perhaps expect to find environment-altering intelligence wherever there is life that's been around and evolving for a long enough time. (How long is long enough? No idea.) But I mean that in the most general sense. Something that is, somehow, smart enough to alter its environment on a grand scale to suit its needs. Should we expect this thing to look anything like a primate? Certainly not. There is a three billion year long sequence of changes that led from the beginnings of life on earth to us. Each change effected what changes were possible for the future. Alter what happened at any of those steps, and you alter the whole sequence. And because what steps are taken are determined by the random, probabilistic process of mutation, you can basically guarantee that the steps will be different.

But, it's probably safe to assume that the general, functional goals of life will be largely the same wherever you go, even if the details of how they accomplish those goals vary enormously. Live, stay alive, maintain a lineage that doesn't die out. And as I said above, forcibly altering the environment to suit you and to not kill you is a great way to accomplish that goal.

Some people think that, given the vastness and the age of the universe, that even if the absolute chances of intelligent-environment-altering life evolving on any one planet are low, it should have happened SOMEWHERE by now, and by that we mean somewhere other than earth. Given the vastness of the universe, some people think that intelligent life must have appeared quite a few times by now - enough times that, it's very strange that we haven't yet found evidence of them yet. A lot of the parameters these people use to make these conclusions are themselves guesses, so it's hard to say how right (or wrong) they are.

“Yes, our brains got bigger AND our tools got more complex, but which change drove which? Or are both changes just the side effect of some other driving source of selection?”

May be because of my education, I really don’t know why, but I’ve always been inclined to think –as a hunch- that spatial understanding of any “form” or “shape” of everything around us could be the first source to this kind of development. This is also caused by an architect and an art historian –severely rejected by architects and hated by art historians in his time- who probably was born 150 years earlier in my opinion. Gottfried Semper. It’s out of our subject, but shortly he claimed that even the most complex architectural designs were born -long before any architectural thought was born- from the most primitive ways of ‘making’. Like knitting something from leaves... It just makes sense to me, in layman’s terms.


That's very interesting. I might have to look up some work by this person. At first blush it makes sense to me too, but I don't know the details of this man's idea. Heck, just given the laws of physics, there's only so many ways you can build a wall.
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Re: Hand<->Brain<----->Brain<->Hand?

Postby psionic11 on October 14th, 2011, 12:59 am 

I hope to contribute some fundamentally different points to consider. I've skimmed most of the post, and do agree with most of the points presented. However, I'd like for us to consider a viewpoint not so much grounded in bipedalism or other specific physical developments in reaction to the environment. I'd like to consider certain features all animals share in reaction to their environment.

-- when you throw a frisbee to a pet dog, or feed your fish on the far side of the bowl, all organisms share a sense of distance, reaction time, and probability curves where something moves in a certain way and if I can get there in time (or avoid that path, in the case of being chased), then I can react in a certain way as to maximize my goal for that reaction. Bottomline: organisms have a built-in "physics engine"...

-- the cerebella of various organisms are specialized for their environmental niche. Recall that the cerebellum handles fine-tuned, repetitive, coordination of the organism's movement in correspondence both to its internal routines but also its standard reactions to the external environment. Electro-receptivity in deep-sea fish correspond to fast-moving tree-dwelling mobility in land mammals. The cerebellum handles the quick motor-control reactions to the environment, regardless of particular physical manifestation (hands, pectoral fins, skunk scent glands, squirrel dexterity, bird flock fear-flight reactions). Bottomline: cerebella foremostly enable reaction; organism-specific appendages obey the cerebellum.

-- cognition, planning, and envisioning a goal and series of steps is the domain of the executive parts of the brain: the cortices. I believe it's not so much the particular appendages of the organism -- bear paws, human hands, bird beak or tiger claw -- that largely determine the effectiveness of the appendage, but moreso the cerebellum/cortex that takes advantage of the available tool. A porcupine's quills or an armadillo's armor are definite survival advantages, but it is the active, purposeful, and precise offensive use of appendages, like the claw or wing, that propel the survival advantage of the organism in question. Bottomline: built-in appendages alone don't make the game, rather, it's brain + appendage that drive the organism's survivability.

In short, tho I'd like to dwell more on the topic, the score of evolutionary bonuses afforded to the human -- hands, bipedalism, sweat glands, larynx, amylase, binocular color vision, large working memory -- are all made more effective by the concurrently larger cortex and cerebellum primates enjoy.

It's mostly brain ==> hand.
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Re: Hand<->Brain<----->Brain<->Hand?

Postby çağla on October 14th, 2011, 7:14 am 

Yes you understand me correctly.

I understand that quality of being an anomaly is nothing more than other anomalies other species present that is defined in biology. (I have just the advantage of shouting back from millions of years which means
nothing in this context.)

“The difficulty comes in the practice, which is so often the case in biology. Simply quantifying the phrase "the selection pressures imposed by the environment" is a monumentally complex task that has so far only been done in the most simplified ways possible.”

So this is about,

- defining different environment(s), for different species, changed in different rates and ways, in the time line of millions of years according to connect an accumulation of a basic data and move from there.

-Selection pressures in general then are extracted from these examples and situations constructed with the knowledge derived from above.

-and then they are connected with each other in a bigger scale to produce more general kind of defining knowledge.

So this is somewhat circular, not linear in thinking? (It actually looks like a spring with a wider base, getting smaller in radius to as it goes up as a way of thinking. )

------------

By human alienating itself from nature, I actually mean very simple things rather than any philosophical aspect. We don’t grow our own food, do not make our own clothes or build our shelters. Sometimes, what has to be done in some of these processes can even upset us. Killing living things, experimenting on them, cut down a part of a wood for building houses... Can we live without those? For example, I don’t know if you eat meat, but can you kill a chicken and prepare it for dinner from scratch? I don’t know if I can. Probably easily when I HAVE to, but my point is, this is actually the most basic problem.

I mean the base of the old pyramid. What you defined before as the “strong instinct” in terms of being human, is about human being more human or animal, because in accordance to survive it requires us to stay ‘animal’? It seemed to be something so fundamentally basic that never really changes in time. In very simple layman terms, survival is so important for life in general, what we are not using anymore has to be always there to be preserved in the most primitive form, just to secure this. I managed to confuse myself at this point, so I am leaving this here.

As long as we’re aware that we are to stay ‘animals’ in the deepest sense –in philosophic and scientific terms- we are humans?

About DNA, selfish gene –haven’t read the Dawkin’s book yet- and generations, I follow what you mean in a very simple way.

“Should we expect this thing to look anything like a primate?”

I am inclined to think that way, but not in strict terms of the qualities of a primate. In terms of developing a physical way to be able to probe, ‘interpret’ shapes and forms within their relation to the space around them and itself.
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Re: Hand<->Brain<----->Brain<->Hand?

Postby Paralith on October 14th, 2011, 7:18 am 

Actually, psionic11, neuro has already made a point of explaining that a potentially more "useful" appendage is essentially useless without the proper neurological elaboration to make use of that appendage. We all agreed with that point.

The hand ==> brain part comes in if we're talking about specific selective forces and sequences of changes. If there's no selective force in favor of more "useful" hands, then the morphology might pop up in a few individuals without the additional brain changes, and be an essentially neutral trait. However, if some aspect of the environment suddenly makes the use of those appendages beneficial, that would actively select for any brain changes that would improve control and use of that appendage. And then, once you have all the traits necessary to enter into that appendage-using, perhaps tool-using niche, perhaps being in that niche will exert yet other selective forces on the brain, perhaps pushing for a generally larger brain. And perhaps this may not have been possible without that first step forward with hands and tool use. I believe part of cagla's OP was asking whether something like this happened or not.
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Re: Hand<->Brain<----->Brain<->Hand?

Postby çağla on October 14th, 2011, 7:33 am 

psionic,

My main question was on the very first possible baby steps causing of the evolution of the brain. Not how it happened after it already reached to a certain level of development.

Some solid support of implication should have come from outside, after all the development is not seeded in independently.
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Re: Hand<->Brain<----->Brain<->Hand?

Postby çağla on October 14th, 2011, 8:16 am 

Paralith,

I tried to look for some brief articles handy and conclusive on Semper, but failed the quest. There are several things, but nothing directly related. It's been a long time that I've read a phd thesis by Francis Mallgrave which I cannot find right now.

The issue arises from a discussion on architecture as "ornament vs structure". Key word is "primitive hut".

I'll post if I find anyhing later.
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Re: Hand<->Brain<----->Brain<->Hand?

Postby Paralith on October 14th, 2011, 10:14 am 

çağla wrote:“The difficulty comes in the practice, which is so often the case in biology. Simply quantifying the phrase "the selection pressures imposed by the environment" is a monumentally complex task that has so far only been done in the most simplified ways possible.”

So this is about,

- defining different environment(s), for different species, changed in different rates and ways, in the time line of millions of years according to connect an accumulation of a basic data and move from there.

-Selection pressures in general then are extracted from these examples and situations constructed with the knowledge derived from above.

-and then they are connected with each other in a bigger scale to produce more general kind of defining knowledge.

So this is somewhat circular, not linear in thinking? (It actually looks like a spring with a wider base, getting smaller in radius to as it goes up as a way of thinking. )


I don't exactly follow the steps you outline here, so I'm not sure what about them is circular. But it does seem to me that you're still envisioning something well beyond the scope of evolutionary studies today. Most studies focus on a single trait or a few traits, and try to understand how those few traits function in the environment. Or if you're looking at a timeline of fossils, we try to understand how one or a few traits change through time, and given that pattern of change and what (little) we know about those organism's environments, try to draw some conclusions about what evolutionary forces actually drove those changes.

If you have genetic data, you can look at the patterns in that data for signs of positive or negative selection in the (relatively) recent past, and perhaps make estimates of the strength of that selection. But connecting these patterns to actual environmental pressures is a whole separate task, and one that has only been convincingly done for a handful of individual cases. And this is mostly because we still don't fully understand how many of our genes function. The bridge between genotype and phenotype is very incomplete.

In short, I was just trying to say that even though many of the theoretical principles behind evolution and natural selection are quite simple, the actual results of these processes in the real world can be very counterintuitive. You're applying simple ideas to an incredibly complex system. A simple pattern can look very different when it is scaled up by many orders of magnitude.

By human alienating itself from nature, I actually mean very simple things rather than any philosophical aspect. We don’t grow our own food, do not make our own clothes or build our shelters. Sometimes, what has to be done in some of these processes can even upset us. Killing living things, experimenting on them, cut down a part of a wood for building houses... Can we live without those? For example, I don’t know if you eat meat, but can you kill a chicken and prepare it for dinner from scratch? I don’t know if I can. Probably easily when I HAVE to, but my point is, this is actually the most basic problem.

I mean the base of the old pyramid. What you defined before as the “strong instinct” in terms of being human, is about human being more human or animal, because in accordance to survive it requires us to stay ‘animal’? It seemed to be something so fundamentally basic that never really changes in time. In very simple layman terms, survival is so important for life in general, what we are not using anymore has to be always there to be preserved in the most primitive form, just to secure this. I managed to confuse myself at this point, so I am leaving this here.


The part of your comment that I have bolded is, I think, the answer to your concerns. Yes, we humans have modified our environment to the point where most of us don't actually have to dig around in the ground or muck about with animals in order to eat. But if we had to - we would. We are back, again, at flexibility and adaptability. Sure, today we control our environment (more or less). Maybe tomorrow we'll mess it up and lose control. Will we die out as a species? I highly doubt that. Unless the way in which we lost control was incredibly, utterly catastrophic to the planet itself. But if there is a way to survive, humans will find a way and they will do what they have to. That is the story of our history. We spread out to more places on the planet than any of our ancestors. We found, adapted to, and thrived in nearly every environment we ever encountered. We did it so well that anything that was remotely competitive with us - any of our ancestors or hominid family members who were still around - have all died out. Leaving only us, the last twig on a once bushy tree.

The lovely thing about lack of skill is that, it's just a lack of skill. One individual with a learning, flexible brain can gain skill they once lacked. The great majority of the way humans have changed in response to gaining control of our environment is behavioral, not genetic. And behaviors are flexible. If the environment changes, they can also change, without having to wait for the next generation and the roll of the mutation dice. Most humans don't learn the same things they learned to do 20,000 years ago, but we do still learn and adapt and use our fabulous brains, in many ways that our ancestors from 20,000 years ago could never dream of. But personally, I don't see anything unnatural in that.

As long as we’re aware that we are to stay ‘animals’ in the deepest sense –in philosophic and scientific terms- we are humans?


I guess I really don't know what you mean by "humans staying 'animals.'" Biologically, we're animals. Like any animal, we have a combination of traits and features that are unique to us, which collectively make us the distinct species of "human." But a human is just a type of animal.


“Should we expect this thing to look anything like a primate?”

I am inclined to think that way, but not in strict terms of the qualities of a primate. In terms of developing a physical way to be able to probe, ‘interpret’ shapes and forms within their relation to the space around them and itself.


Yes, in terms of their functional capabilities. No in terms of the specifics of their morphology and their history.
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Re: Hand<->Brain<----->Brain<->Hand?

Postby çağla on October 15th, 2011, 5:48 am 

Paralith,

I think you do follow my steps, because the explanation you made was helpful to me for drawing some sort of borders. I need to read on the subject, but I thought it would be more confusing to me at this step. May be I should try.

I was trying to say that I am more inclined to take human as an animal than as 'human', because our time lived in nature is much much longer than the time we lived in our little civilisation, while understanding how two sides are legitimate.

I confuse myself with comparing this definitions with social-cultural understandings of "to be human" which is promoted through known history/art history with different, sometimes opposing tendencies. I find this self-promotion to be fake and unnecessary fuss at most times. When you study art history, you have to put up with this sort of tendencies all the time. Actually with a cold, severe judgement, I could say that is the basic core of traditional art history. Human ego. Something no more than a sentiment may be, but which could cause me to get snarky, if stated by someone out of the disicpline. Enough confessions.

Thanks for your responses. Is there any reading material you think would be suitable as a book, something essential with charts, and every aspects? Or do you think it would be better if I make a reading search by key words in my mind, by myself? After all that would draw another line for me on what can I learn for now.
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Re: Hand<->Brain<----->Brain<->Hand?

Postby Paralith on October 15th, 2011, 12:05 pm 

Well, I think a bit (or a lot) of egotism in studying art is not unwarranted. After all, art history only studies human art, and arguably humans are the only species alive today that spends so much deliberate effort in creative expression anyway. Art made by humans is going to be based in human perception and human experience, regardless of how similar some of those perceptions and experiences may or may not be to those of other animals.

And again, this all comes down to your particular interests, to your particular question. Humans are animals. Humans as a cohesive species distinct from our ancestors have a history of a particular length. And the same can be said of any other animal. A baleen whale is a kind of animal, and as a species has existed for a certain length of time. And if you compare the length of time the baleen whale as a species has been around, to the length of time the entire multi-species lineage that connects baleen whales to the earliest life on the planet has been around, yes, one of those time segments is way shorter than the other. Humans are not special or different in this regard. But would you say a baleen whale is only partly a baleen whale, because of this fact? No, but you might prefer to focus specifically on all those things which make baleen whales different from their ancestors and near relatives because that's what you find interesting. And humans are nothing if not interested in themselves and how they are different from other animals.

As to reading recommendations - learning to navigate the primary literature is always a good skill to have, but when you're relatively new to a topic, it can be way too overwhelming. A good textbook is always a great place to start. Unfortunately I haven't read that many different textbooks, and there are a LOT of them out there. So I'll just say that my undergraduate evolution textbook was Evolutionary Analysis, and the textbook my graduate university uses to teach an undergrad course on human evolution is How Humans Evolved. If memory serves, both of these books also contain good bibliographies full of articles, which may not be a bad place to start digging into the literature.
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Re: Hand<->Brain<----->Brain<->Hand?

Postby çağla on October 16th, 2011, 5:28 am 

"But would you say a baleen whale is only partly a baleen whale, because of this fact?"
That's a good question. I get the answer.

" No, but you might prefer to focus specifically on all those things which make baleen whales different from their ancestors..."

Regarding to this, I think the concept of "intteligence" confuses me when applying this to our ancestors. Also time, as I have to think of a begining and an end to tackle it. I'm inclined to see the whole thing divided into events and processes with borders. I need to learn and have some time with that knowledge to have a sense of it.

My particular interest is our species. (I just realised -related to this-, why the name is specie's'. :) Bit slow, eh?)
By the way, thaks for the book names.
Last edited by çağla on October 16th, 2011, 6:31 am, edited 1 time in total.
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Re: Hand<->Brain<----->Brain<->Hand?

Postby çağla on October 16th, 2011, 6:23 am 

çağla
 


Re: Hand<->Brain<----->Brain<->Hand?

Postby Paralith on October 16th, 2011, 8:03 am 



Thanks - that was very interesting. Not sure I follow it all exactly, but maybe one day I'll pick up a book on Semper.

I have to say, since Semper found the origins of architecture in weaving, I bet he would have been fascinated to learn about how apes build nests in trees at night. It's almost like an extremely rudimentary form of weaving. Certainly it's the closest thing to architecture that you'll find in the primate world. It might even be that our history as primates is what predisposed us to weaving in the first place, as opposed to, for example, tunnel digging, which might have been the case if instead we were really intelligent moles. :)
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Re: Hand<->Brain<----->Brain<->Hand?

Postby Forest_Dump on October 16th, 2011, 10:46 am 

I too give my thanks for this reference to Semper. I hadn't heard of him before but I will try to hunt him down. Some years ago I took an interest in weaving and fabrics and, in particular, how some of the concepts have been like "memes" with ideas like "the fabric of time" etc., the story of Rumpelstilskin, the perhaps archaic terminology of wedding in the english speaking world (i.e., the sinestral vs distaff sides) acting to weave together kinship units, etc. Really fascinating stuff and recent anthropological studies on weaving, etc., have provided lots of directions for all kinds of new insights.

Unfortunately, seemingly integral here is the question of whether what came first, architecture or other forms of weaving - a chicken and egg question of which came first. Para has noted that apes do a rudimentary form of weaving in the construction of nests at night. Other critters do this too ranging from beavers who do some rudimentary weaving for dams and lodges, to birds like orioles, which construct much more elaborate nests. We could then ask whether it was the architecture of some of these latter woven nests that inspired the first humans to weave baskets and bags. Of course, the first baskets or bags were more likely to have been made of leather or perhaps bark folded, joined and/or tied and preserved examples of the latter, while not very old relatively, often do include stitching at the top both to stabilize the rim of the wooden, bark or leather bag, and as decoration.

In actually looking at the archaeological record we first need to bear in mind that all this stuff is perishable - it rots. So, only under extraordinary circumstances will we find preserved evidence of either woven architecture or other things like fabric bags, baskets or clothing. And, all other things being equal, the latter is more likely to be preserved because it is smaller than architecture and therefore more likely to find its way into contexts where it could be preserved (e.g., in pits, wet deposits used for misc. garbage, impressions in fired pottery or even in hearths, etc.). Perishable architecture is less likely to be preserved because it is more often above ground and therefore exposed to decay, etc. (Of course there are exceptions.)

So, here's about what we can say with confidence. Woven fabrics as possible clothing, baskets and/or bags do go back to the Pleistocene, at least in the Upper Paleolithic (e.g. the headdress of the Willendorf figurine). However, I think it is possible to point to architectural weaving and knots, independently, being older. Perishable huts MAY be earlier than any weaving (e.g., the early Middle Paleolithic hut at Le Lazaret) and any development to stabilize that kind of structure to make it free-standing (Le Lazaret appears to have been a fairly simple lean-to) and support a hide covering would require some form of fastening of support poles at the tops, for example. That implies some form of perhaps sinew but tied off with a knot. Similarly, although it has been posited that pre Homo sapiens (i.e., Neanderthals) didn't necessarily have fitted (fur or hide) clothing (because of the lack of needles with eyes, etc.), they did have stone awls which would have been used to cut holes in hides, etc., and some form of tying off cords or sinews must have been fairly early.

Similarly, tying knots for other purposes is likely to be very early. Probably the earliest would have been in hafting a stone projectile tip to a spear, etc. While some form of mastic adhesive could be early, most of these techniques require a certain mastery of pyrotechnology such as in boiling down certain tree saps, etc. Probably just as early or earlier was simply tying notched or stemmed stone tools to a handle probably using sinew. And that requires some form of knot. Similarly, non-projectile fishing gear such as the use of a fish hook (especially an eyed fish hook) or certainly nets would have required some form of knot and of course the latter involved weaving. Knots would also have been important in the use of bola stones, probably stone axes (the same as projectile tips), etc. And, of course, any kind of necklace, etc., stringing simple pierced shells, etc., would require some kind of knot (e.g., Ucagizli?).

So, while the hypothesis of non-architectural weaving predating architectural weaving or other uses of knots, etc., is an interesting idea that could get some legs but I am not convinced.
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Re: Hand<->Brain<----->Brain<->Hand?

Postby charon on October 19th, 2011, 6:55 pm 

çağla

I've just read on another thread that English is not only not your first language but that you've never been to an English-speaking country.

In that case I'm most impressed. You're doing very, very well! How did you reach this standard? I wish I was as good in another language.

(Sorry, chaps, nothing to do with the current subject) :)
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Re: Hand<->Brain<----->Brain<->Hand?

Postby çağla on October 28th, 2011, 9:15 am 

charon wrote:çağla

I've just read on another thread that English is not only not your first language but that you've never been to an English-speaking country.

In that case I'm most impressed. You're doing very, very well! How did you reach this standard? I wish I was as good in another language.

(Sorry, chaps, nothing to do with the current subject) :)


I studied English in high school charon. Or rather I studied high school in English. It's not a big deal. So, honestly, it's supposed to be much better. I try to mention it when it comes up, because language barrier is a culture barrier and can be disastrous in communication sometimes. I studied other languages a little, -which I don't have a clue now- but you pick the one your own culture accepts.

In my country English is everywhere if you like to listen. Especially in my community, almost everybody understands English in a good level. American and English culture has been dominant for a long time before the current government. We have channels in English, American shows in channels, schools in English, English people to teach English... When I was a child, majority of the teachers in private schools, courses were English. There are also German and French Schools, but English is dominant. It's now more turned to American in the last decade, though there are very few Americans. But before we had a certain English curriculum, which I think is standart for most of the other developing countries.

The only way to be good at a language is to use that language. And everyone can do that. It's an organic, powerful, living thing. Not to mention a tyrant,lol. My advice, find a one you like and dive in it. Reading and communicating in another language is a fascinating thing, and you will learn so much than a language. I'm planing to start another one as soon as I get myself on my feet. :)
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Re: Hand<->Brain<----->Brain<->Hand?

Postby çağla on October 28th, 2011, 12:44 pm 

So, while the hypothesis of non-architectural weaving predating architectural weaving or other uses of knots, etc., is an interesting idea that could get some legs but I am not convinced.


OK. But there is also a link between the style of little objects and architecture in general through history.

Do you think there could be a link between clothing and the early form of architecture? Not just about physically, but also psychologically as the need to feel free and safe.

Edit: I didn't know about Üçağızlı Cave. I couldn't recognise the name first, then I thought you might be talking about some sort of a knot or weaving, because üçağızlı means "triplemouthed".
E2: No, I think "three mouthed" is more accurate.
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