I believe the relation between opponing thumb and intelect resides in the hability to count with fingers. 

My problem is ... again and again... the dolphin, that has no hands and still can count up to five !

Great apes have an opposable thumb (but see Wiki), thus the opposable thumb came before the intellectual capacity of the brain, but

The intellectual capacity of the brain is rather vague as an expression. Some people claim humans only use 10% of the brain. Whales should have bigger brains than humans.... etc...

Is intellectual capacity related to brain size within the humans?

Thank you, dear Marcel, for explaining the opponency movements.

As an anatomist, with particular interest in the human hands,  I should add that in fact, this singular movement of the thumb is a bit more complex than my question. 

It depends on the whole skeleton of the hand and its rotation capacity in relation to the wrist.

The singular characteristic that hominids' hands have, and which is different from the primates, is the trapezo-metacarpal joint, with sferoid (selar) surfaces, permitting the rotation of the thumb.  This is unique to hominids, As for most of  the primates, including the great Apes and chimps, the hand skeleton only permits gross prehension, through opposition of the four fingers against the palm of the hand, as used for grabing tree branches, or throwing objects for defense.

As for the skull capacity, I am looking for the link of an article, to answer you and dear Kamal.

Thank you for your prompt interest in this issue.

I wish you a great weekend! Kind regards, M.

I do agree with @Kamal,  the intellectual capacity of the brain have evolved first!

Thank you, sirs! 

You just offered me the best strenous exercise I could have on a Saturday evening, jumping up and down for books on the shelves, looking for bibliographic documents to answer your vividly interesting remarks.

I believe this question has no acceptable scientific answer. (and this is why I proposed it, because it haunts my imagination, as a proud-to-be-humanoid...)

Here's .what Penfield and Rasmusen have to offer in this regard, as to the human brain areas of sensitivity and motion control of the body (please notice, on the 3D adaptation, the huge, enormous proportion of brain cells activity devoted to the thumb, regardless of other corporal areas...)

Dear @Maria, this paper may be also good for this thread! It is at Research Gate also! Penfield was cited few times!

Penfield W, Boldrey E. 1937. Somatic motor and sensory representation

in the cerebral cortex of man as studied by electrical stimulation.

Brain 60:389–443.

Penfield W, Rasmussen T. 1952. The cerebral cortex of man. New York:

Macmillan.

Penfield W, Welch K. 1951. The supplementary motor area of the

cerebral cortex; a clinical and experimental study. Arch Neurol

Psychiatry 66:289–317

Wow, thanks, Ljubomir Jacić !!!

These studies were performed on anatomical and neurologic brain specimens.

There's a living Portuguese Neurophysiologist working in USA, António Damasio, doing some important research in this field, on living healthy brains.

I'm anxious to know wether there's some more recent evolution, namely in regards to computer keybords, by the moderrn brain. Aren't we still adapting and evolving? 

I found it!

Dear Marcel and Kamal, I thought this might interest you:

On the front cover of Jean-Pierre Gasc (2004) «Leçon d'Anatomie Comparée - Histoire Naturtelle de la tête» you'll find an interesting image, showing the natural evolution of the skulls. The parietal lobes of the brain that receive information and comand the motion of the body parts have little to do with the frontal lobes, that we believe to be responsible for intelligence and intectual capacities.

The main part that evolved in the Hominids, were the frontal lobes of the brain, in an equivalent measure to what we believe to be human intelectual capacity.

(the frog and the chicken have no frontal lobes. Yet they move their hands. Do you think that there's hope for the chicken and the frog to develop intelectual capacities??? I hope not. I'd hate to see the World under the government of chicken and frogs... -please don't comment on this!-)

The anatomy of the hands improved writing skills that might have accelerated intellectual human brain development not only from a genetic but also experience point of view. I presume that people that write a lot will develop certain brain centers more than people that do not write at all, right? Where are these brain centers linked to writing located?  In the frontal lobes?

Did the opposing thumb allow acceleration of brain development via the development of writing skills?

Relevant literature I did not read myself?

James, Karin H. an Atwood, Thea P. (2009).The role of sensorimotor learning in the perception of letter-like forms: Tracking the causes of neural specialization for letters. Cognitive Neuropsychology.26 (1), 91-100.

James, K.H. and Engelhardt, L. (2013). The effects of handwriting experience on functional brain development in pre-literate children. Trends in Neuroscience and Education. Article in press.

If intellectual ability of the brain would have not originated prior to the thumb opponency, then there would have no systematic evolutionary progress in the history of mankind. The former is the driver of the latter.

Thank for sharing the question.

Perhaps it depends on the scale of analysis, e.g. micro-evolutionary processes versus macro-evolutionary processes? You need the brain to develop/use the anatomic-based tool (thumb opponency), but once you have the tool you can start to develop other brain centers, e.g. those related to which tools you will use, including writing tools, agricultural tools, technical tools to make complex devices like watches, etc...? Training skills influences brain development or brain development influences training skills?

An absolutely stunning, smashing question!

Of course, it goes with out saying that we here will never settle the question. With that said, I tend to feel that the opposable thumb has more to do with our abilities and consciousness than we would like to think, nor are able to admit. Thinking is more to do with appreciating the opposing view or possibility, and possessing an opposing thumb may not necessarily determine that ability, but may encourage it. I think it certain that as man began to make tools, that in turn constrained and help form the evolution of our brains. I mean, recent research has proven that those persons who use technology on a regular basis are in fact wired differently than the rest of us; in other words, the younger generation tend to think differently than the rest of us older types who grew up with typewriters, books and other varieties of older tools.

http://www.pewinternet.org/2012/02/29/main-findings-teens-technology-and-human-potential-in-2020/

http://triplehelixblog.com/2012/02/generation-y-the-internet%E2%80%99s-effects-on-cognition-and-education/

Even political tendencies cause differences: http://www.washingtonpost.com/national/health-science/conservative-and-liberal-brains-may-be-wired-differently/2014/11/03/3903c25e-6057-11e4-8b9e-2ccdac31a031_story.html

In time, human interaction with computers and advanced technology may prove to deflect evolution of humans even further afield from what we knew earlier or what was demonstrated earlier in time. So, one may argue that the very tools we make in turn effect our cognitive abilities and worldview, that is to say, these things help shape who and what we are. 

I would venture to say that the brain did not form the opposable thumb, hence, the opposable thumb has effected our brain. Anyway, that's my thoughts on this enigmatic problem or question. Of course, I eagerly await for opposing views, in order to, increase my own understanding of the human brain and evolution. 

thank you, Luisiana, for your interestring, enthusistic remarks. 

I actually feel like the silliest of persons, when I watch my young children manipulating their cell phones. (they play games with two cell phones in both thumbs, because «one hand is boringly easy» and I find it difficult to send written messages with one ,miserable thumb! Are their brains already different from mine?

Thank you, also, again and again, dear Marcel, for your outstanding comments and bibliography! (I though you might have written some on these evolutionary subjects!)

This has become an interesting debate. Lively and intelligent, nonstop heart and brain acceleration! Thank you!

According to the evolutionary scale, I just checked that Homo habillis is precedent to Homo Sapiens, up to two million years before...

(again, quoting from Wilson, the Hand)

(By the way, Homo Erectus is my favorite, because he had the intelligence and hability to stand up and expand horizons!)

Thank you, dear Cecilia! Interesting.

Aristote used, what is to me, the best definition of the human hand, as he called it 

«THE INSTRUMENT OF THE INSTRUMENTS»

We'll have to add teeth and tails and jaws, to this definition!

Evolution is random in nature , it itself don't know what is right or wrong.

But logically both brain and thumb should evolve together , because brain controls the thumb, I cannot understand brain evolving ahead of thumb to hold objects or thumb evolved and brain adjusted.

I may be wrong, but evolution is very slow process and I believe it should happen gradually with both brain and thumb equally evolving as per need.

Regards,

Bhushan Poojary

Dear All,

I like the approach (his first answer) of Marcel.

I think the starting question of this thread is too difficult and verifying the rightness of answers or guesses is uncertain and highly speculative. One could formulate a partly similar question much easier to assess with simple correlation analyse: are there a correlation between the intellectual capacity (not brain mass) and the handiness (manual skills) of Homo sapiens?

Thank you, Brushan for your wise words. 

In fact, we are about to diiscuss here, on wether the egg came first, or if the chicken had to lay the egg for a start... (neverending vicious circle! - and you got the wise answer. Thank you!

Anyway... 

this question of the brain volume and the relation to intelectual capacities, and to the use of instruments, really puzzles me.

To this purpose, R. Quinlan proposed a «directional selection» in the evolutive transition of hominids through the Paleolytic with a correlation between the brain volume and the technological capacities.

you'll find his interesting article in the following link:

http://public.wsu.edu/~rquinlan/mptoup.htm 

Dear All,

An animal example to the comment of Cecilia on the mouth use of fishermen: rats (Rattus norvegicus) are able to avoid the operation of mechanical traps by throwing pebbles with their legs and mouth. I remark, the seeing capacity of rats is very weak but they are intelligent.

Dear Marcel,

What about the bill ability of birds?

Yes, Cecilia and András. If you follow Quinlan's link, just above, you'll find some strange similarities between stone carving by hominids, and the shape of birds nests... strange?

What was first: The chicken or the egg? This question is not precise enough.

For instance, the egg was first because other organisms produced eggs before  the chicken evolutionary appeared.

So the question might be: What was first: the chicken egg or the chicken? I would be inclined to say: the chicken

Dear Maria,

As far as we know that the thumb opponency comes after the intellectual capacity of the brain.

just a personal opinion, but i think the brain must've somehow come first for a thumb to operate correctly i mean coordinating a thumb is not that computationally easy{if we presume that mind processes are like natural computations of course.}, in simple terms, is a book useful when there is nobody to read it? but still i think the most important thing for such a question is what you want to believe actually.

Thank you Marcel,

Yes, certainly the chicken came first, as an evolutionary perfection of the lizard.

In which case, both Kamal and you, would also be absolutely right, when you place the evolution of the frontal lobes before the thumb opponency. 

and then, as a result, Lucy was the inventor of Mathematics, as with the help of the thumb opposing the other fingers, she learnt to count to 3 or even 4! and this imediatly led to further development of the brain, and the improvement of tools. And we restart our vicious circle and evolutionary turmoil, in which the hands improve the brain, and the brain further improves the hand motion. Kamal is the living proof that the Sapiens has perfect, precise motion of the hands, as a surgeon, in strict correlation with a superior intelect.

Our chicken was useful, as usual...

Thank you Cecilia, for the improvement of the intelectual brain, with the introduction of aesthetics.

The hands in Medicine and in Art are one of my favorite subjects, for many years, now. This issue offered me several good conferences and publications.

(I notice that the human interest for Art, since the beginning of the species, closely correlates with the improvement of aesthetic representations of hands, and also, with the development of better surgical tools and the gradual perfection of medical and surgical practice .

You can see some beautiful artistic representations of these thoughts in the following link. (It is written in Portuguese, but you can follow the course of ideas, through the sequence of the images. I am very proud to have published this book in colaboration with my Mother, who is also a Scholar.)

 https://www.researchgate.net/publication/265107097_Cultura_e_Conflito_As_Humanidades_e_as_Cincias_-_AS_HUMANIDADES_E_AS_CINCIAS_-_Dois_modos_de_ver_o_mundo

The upmost perfection of the relation between hands and arts belongs to the French scupture by Rodin - or by his lover Camille Claudel-  with the composition entitled «La Cathédrale»).

As I tried to draw this scupture, I noticed that the hands belong to a man and a woman, and maybe a black and a white persons. -because my sketch is so imperfect, I called the Chapel, which is smaller than the Cathedral-

I shoulds like to offer this sketch to Cecilia!

thank you all for your precious contributions.

Book As Humanidades e as Ciências -- Dois Modos de Ver o Mundo

Dear All, In my opinion the thumb opponency in human came after development of  intellectual capacity of the brain.  

I did some short researches of opponing thumbs. They are known besides for hominides also for koalas, chameleons, most of the birds, scorpions, crabs with their tongs, opossums etc.

To state that intelectual capacity of humans developed before the thumbs opposed, because the highly developed brain is necessary for thumbs positions, is problematic. The position of fingers or other gripping devices depends mainly on the natural requirements.

Thank you dear Hanno!

Quite useful, as usual.

your contribution is even more puzzling for the question in debate. But it also somewhat adds interest to our quest! Thanks!

I also found the Lémur, a prosimian from Madagascar...

this tiny lovely little animal, well placed in the scale of evolution, before the apes, didn't even need an opponent thumb, because it has a long tail to jump from tree to tree. 

These more inferior animals with opponent thumbs lead me further to question wether instead of wandering if thumb opponency came before the intelectual activity of the brain, we should admit that the evolution of the brain and intelectual activity led to the perfection and maintenance of the opponing hability, and those that didn't exercise their thumb for lack of intelect, simply lost their opponing hability, though evolutionary times.

There we go, round and round, again...

Thank you Hanno!

If looking at animals I remember the sloth with two or three toes. It uses its toes without any intelectual effort, just functioning by poor physics. Therefore tools to grasp must not necessarily need the efforts of a highly developed brain. Complicated question.

I believe the relation between opponing thumb and intelect resides in the hability to count with fingers. 

My problem is ... again and again... the dolphin, that has no hands and still can count up to five !

Please dear friends,

could you imagine that brain developed with the abilities of the body. Standing up is followed by seeing more, opposing thumbs enables handicraft, etc. I know thats the opposite of the most answers.

thank you, Hanno . Your contradictory remark keeps the fire going ! 

I keep my doubts on the whole subject, which is never ending entertainment for our Sapiens brains.

As I remarked, earlier, what troubles me is the fact that Homo Habilis precedes Homo Sapiens and also the fact that I think clearlier after practicing yoga, and also when my body is rested, as in the early morning.

Thank you for keeping this intelectual fire going! Dear Hanno!

Dear All,

For surviving a living being uses each part of his/her body. Evolution because of the continually efficient environmental conditions must be a multisided and permanent process. Thus, evolution is a too complicated and too slow process in order to prepare a true and operating model. I think questions like what came first... are typically human questions showing our very brief life experience. It is a wonder we are able to imagine – but how – situations and processes so distant and unrelated to our practice and mentality.

I am waiting to learn from the experts...

So there are many chicken/eggs problems to be applied to the human body as a whole also accepting there is direct or indirect inter-connectivity between the cells/tissues/organs...., also at different evolutionary time scales? 

Dear all,

We are all waiting for the answer, because it is not simple...

But, in the meantime, we all learn a lot from each other's interesting comments.

Thank you! M.

The process of evolution is assumed to a product of selection pressure. Mutations occur at random and conditions allow or repress the manifestation of the mutation.

The evolutionary process does not require a temporal sequence or coincidence of the development of the brain and the arrival of the opposable thumb.

Suppose that the capabilities of the human brain developed in horses. A horse would encounter many difficulties in mirroring the technical development of humans, printing newspapers, climbing into space capsules, and texting on a smartphone while eating spaghetti. Nevertheless, one can imagine the horse's brain devising all sorts of solutions if there were problems or opportunities for a horse to solve or develop. Would a human-brained horse be a slave to fashion?

Evolution fails to explain, because we lack evidence that is time coordinated with fossil changes. What would be the imperative for horses to select for larger brains? Would it be the same imperative for humans? Suppose humans mutated from the best primate thumb to the fully developed opposable thumb. Would this new thumb lead to selection for those who could make more use of it? Possibly. Yet, the primate hand can do very many things that a horse cannot. We could easily write, use a knife, hammer and chisel, and many other skillful tasks by holding tools in a different manner. A horse would have a more complex problem to solve.

Counting on fingers does not require a thumb. Counting can be done many ways, including notches on a stick and knots on a string. Counting is also done by grouping. Those doing sorting can see groups of three, four, five, ... Did it require counting to do so or did one learn to group then name the grouping. Most likely, counting came first, but where is the evidence?

Is it logical to suppose the the thumb came first and humans selected for those who could think of better ways to use it? Did smarter primates select for those who had more dexterity when using their smarts? There were thumbs before their were better thumbs just as there were eggs before there were chickens. One could speculate that the opposable thumb came first for primates, then devolved for those that did not use them. Smarter primates that made better use of their thumbs would be more competitive. Smart primates that developed a better thumb would be more competitive.

Brilliant,as usual,dear Joseph!!!!

It's great to read you.

Thank you !!!!!

Best regards, M.

« You know that you cannot invent animals without limbs, each of which , in itself must resemble those of some other animal. Hence, if you wish to make an animal, imagined by you, appear natural - let us say a dragon - take for its head that of a mastiff or hound, with the eyes of a cat, the ears of a porcupine, the nose of a greyhound, the brow of a lion, the temples of an old cock, the neck of a water tortoise. »

LEONARDO DA VINCI -   Notebooks 

« Movement will cease before we are weary of being useful.

Movement will fail sooner than usefulness.

Death sooner than weariness. I am never weary of being useful, is a motto for carnival.

In serving others I cannot do enough. Without fatigue.

No labour is sufficient to tire me.

HANDS into which ducats and precious stones fall like snow; they never become tired by serving, but this service is only for its utility and not for our own benefit. I'm never weary of being useful.

Naturally, nature has so disposed of me. »

LEONARDO DA VINCI - Notebooks 

Dear María,

"Evolutionarily, it is often asserted without further justification, that the characteristics that define us as humans are: a large and complex brain, the bipedestation, the possibility that we have to handle language and our ability to make and use tools to modify our environment, where we could include thumb opposition. "(This text is part of the introduction of a Treaty of psychical anthropology that I'm writing).

Our psyche was built as a center of regulation and control, as a result of evolutionary pressure. As Llinás says, "the organization and function of our brains are based on the integration of the motricity during evolution". According to this, it is first thumb opposition than increased brain size, which is associated, without major problems, with a greater intellectual capacity, something that is highly debatable.

Thank you dear Cecilia and Dante. 

Quite valuable !

Thank you Dante for sharing your Psychical anthropology notes ! (I'll be interested in reading the rest !) Thank you, dearly!

With due respect to those scholars who believe in evolution, I believe in creation as it has been mentioned in the holy books.It is as simple as the emergence of the first human beings (Adam & Eve) in full shapes with full capacities. The human organs had & will continue to have coordination with the brain as the master of most but not all the bodily functions. Honestly, when I see scientists relying on very far historical events , I become suspicious that there is some lack of the scientific way of thinking which counts upon observation, experimentation, testing, and reasonable conclusions.

Thank, dear , dear Dr. Nizar, for beeing such sweet disagreer. I respect your thoughts and beliefs, very much. You bring valuable contribute to this discussion.

Your point of view is a great valuable sign of respect, and for this, I respect you .

Thank you.

Nizar it is proper to question human evolution. The little evidence derived from primate fossils requires considerable interpretation to show a relationship to modern humans. Most important is the so called missing link.

The question of which came first, the thumb or the brain was answered in 1968. A paleontologist working in the Oldivide Gorge* discovered a remarkable fossil. Gianni Schicchi (also known as Johnny Leaky because of a prostate problem) discovered a fossilized tympanum. As is true with most paleontologist, he was able to reconstruct the remainder of the fossil from this small hint of the whole. First he envisioned the ear canal. From there it was simple to derive the jaw bone and brain cavity. Since the fossil was from an upright hominoid with a forward slump, it could have no opposable thumb. The brain cavity was large, indicating great intelligence. The area of the fossil find had tools in the same stratum. This perplexing discovery implied that while the large brained protohuman could not make tools, it had a way of acquiring them. The brain was not large enough to accommodate morals so acquiring was a simple act of gathering to facilitate hunting. The fossil was named Lucky to misdirect associating morals with its habits. Some descriptions of the fossil omitted the 'k' and that has led to confusion concerning the origin of Lucky as there are several accounts and different attributions of discovery.

Leaky Schicchi continued his search of the area, but years later found among the original artifacts another tympanum. This tympanum explained the tools in the same stratum and how 'Lucky' was able to acquire tools. Reconstruction of the whole fossil from this new tympanum revealed that a second protohuman existed at the same time that had a small brain and an opposable thumb. This second protohuman was called 'Tommy' for the thumb. It is postulated that Tommy got Lucky, but no progeny of this union has been found. While many think the progeny is the missing link, this was not part of the original search. Schicchi broke his watch chain. The original tympanum was found while searching for the link.

When Gianni Schicci died, it was up to his long-time friend and assistant Buoso Donati to read the will. He was questioned about the discovery of the tympani. His account was obviously designed to discredit the man in whose shadow he had long labored. He claimed the fossils were actually fish scales from a meal they had the day before the first discovery. His malice reached operatic proportions. The facts have since been distorted because Dante reported the events in his Infernal Digest and switched the names.

*Not to be confused with the Olduvai Gorge. The Oldivide is on the Red Sea where legend has it that the sea could divide.

Dear all

About the problem what was the first chicken or egg. I think an egg was the first, because the beginning of life is from a cell according to evolution. Egg is a cell. The first cell which can conducts cellular differentiation  is from singlecell living being.

Dear all

About the intelectual capacity of the brain, and the thumb opponency, in my opinion, (an opposable thumb, its control center in the brain, its spine and nerves which connect both )they all came into being at the same time. Left thumb control area and right thumb control area are at different cerebral hemisphere. Left cerebral hemisphere controls the right - hand side of the body. flexibility and dirigibility of Thumb  and controllabitity and coordination of its control area in the brain are promoting mutually and developing together at the same time.

Dear all

During NeonatalPeriod, the brain of Modern human baby cannot control his hands. Following training, the coordination between hands and brain developed gradually. If an opposable thumb had evolved human brain, the baby would have the born capacity controlling hands coordinately.

dear downvoting sir.

https://www.researchgate.net/post/Social_media_Downvoting_and_degrading_in_social_networks-What_are_the_reasons-What_are_the_reactions/13

Dear all

Some knowledge about human brain.

http://www.webmd.com/brain/picture-of-the-brain

Dear all

The cerebrum is divided into a right and a left hemisphere. The left hemisphere controls the majority of functions on the right side of the body, while the right hemisphere controls most of functions on the left side of the body. The crossing of nerve fibers takes place in the brain stem. Thus, injury to the left cerebral hemisphere produces sensory and motor deficits on the right side, and vice versa.

Difference of knowledge should be added in public. That will help the participants in the discussion to rethink .That is why I add it to the discussion..

Thank you, ChunLiu.

Quite useful. And I agree that there is similarity between Humanoid evolution and the evolutive scale in general, and our embryonic and neonatal evolution. In this sense, you may have touched the right point to solve this question.

As human brain develops further, postnatal evolution of hands dexterity happens sequentially..

I love watching babies in their first month, as they discover the motion of their hands and fingers. They spend long hours, staring at their own hands, before starting to discover the surrounding world, with the help of hand grips.

Dear Concha !

You are probably right. Much probably. Thank you. I believe that even when we study these subjects deeply, we should all consider ourselves as «complete lay in the issue, yet curious», as you said. Thank you !

... interesting...

http://www.sciencedirect.com/science/article/pii/S0305440399905927

http://www.iflscience.com/plants-and-animals/innovative-female-chimps-may-have-pioneered-tool-use-hunting

Let me transcript Malik's beautiful answer, through private messaging:

Malik Sabubeh to you11 minutes ago

«glory be to God

I think brain evolution was the first to happen before the hand actually acquired the ability of opposition. In fact , I have not enough knowledge of the literature of anthropology or human evolution, and at the same time I do not think that we are going to have enough historical knowledge of the human evolution so that we can answer such question. We have to deduce the answer from both current scientific understanding of human anatomy and function especially in the process of embryonic development.

I think that the brain eveolved first because we know that in the process of myelination, the motor fibers are myelinated before the sensory fibers. That is the brain initiates the upgradation of the process of interaction with the outside world and does not wait the outer world or periphery of the body to initiate this process of upgradation.»

http://www.iflscience.com/plants-and-animals/discovered-stone-tools-go-back-beyond-earliest-humans

Kenneth W. Krause (2009), Pathology or Paradigm Shift? Human Evolution, Ad Hominem Science and the Anomolous Hobbits of Flores

• Forelimb/hindlimb ratio did resemble that of something more primitive than H. erectus
• Brain’s general shape was most similar to that of H. erectus.  “well-convoluted” brain that could not have simply been a scaled-down version of an H. sapiens or an H. erectus brain.

https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=57&cad=rja&uact=8&ved=0CD8QFjAGODI&url=http%3A%2F%2Fwww.csicop.org%2Fsi%2Fshow%2Fpathology_or_paradigm_shift&ei=OKNeVeD_HYKrU7iRgJgG&usg=AFQjCNEM0yYxZxa5MrWN52MnNYB3epNbqg

Dear Maria,

I was fascinated like you by this news about stone tools before homo habilis. A wonderful info.

Thank you, dear Hanno, dear Krishnan.!

I do wonder if these dating measurements are as accurate as they should...

Can we trust them? I do wonder... My doubts persist.

Dear Krishnan, what a pity that this Hobbit doesn't have any complete hand, that we should analyse in terms of the oponency of the thumb. (I chose Lucy, because both her head and thumb ar easy to analyse, as the oldest complete -!- Australopithecus skeleton...)

Dear Maria,

I´m thinking the same doubts. But they are so convinced, I think we must trust and start a new analysis about human development.

That's what thrills me most about Science, scientific reasoning and Knowledge.

There's constant change and the need to adapt. (and the urge to question every new data ! )

That's why our brains keep evolving, and that's what keeps us going !!! (and this is also why I believe in permanent exchange of points of view, with bright intelligent people such as you, dear Hanno, and others on RG. I am thankful, daily, to be able to come back here for this!)

Yes dear Maria,

some times sciences is like science fiction, some times like criminal story. But always totally amazing and worth to participate.

Dear Hanno! As I read you, I read a declaration of love towards Science... (unconditional love, is to me what links me to Science!)

And it's great to have positive emotions towards the most pragmatical side of our conscience, whilst others have negative emotions, when not coping with pragmatism ...

That's the magic of our lovable science !!!

Cheers to you, and to the Unity of Scientists!

Dear Maria,

thanks for the greetings. But I hope you don´t expect the scientists to drink these "cheers". I already feel so blue.

Please , please never feel Blue, dear Hanno!

Don't forget tro notice the pink colours of the Universe. 

Please think of the colourful rings of Saturn. They are there as a garantee of Joy and happiness to us.

... 

Dear Maria,

thank you for giving me this hint to your question and all your and others intelligent, important, specific, valuable and informative answers.

Thank you again

Peter

When we have similar interests, we should join Hands, and our Brain will compliment.

Thamk YOU, dear Peter. 

Dear Maria,

very nice and philosophical said.

Compliments. Let´s do it!

Peter

 Yes, in fact, although placed in quite distinct ways, both our different questions and their many interesting contribute, do complement...

https://www.researchgate.net/post/Is_our_education_at_schools_and_Universities_focused_on_the_brain_or_hand_What_happens_if_one_of_the_two_are_enhanced_or_conversely_reduced

dear Maria,

my English is not smart enough to answer in this highly sophisticated manner you respond.

thank you I enjoy it very much

Peter

That I think it must be a synergistic effect. One without the other would probably radically change human development.

Dear Joseph,

How absolutely interesting... 

I could imagine the brain without hands, easily getting into psychological stress or disease (I always build things with my hands, as a soothing, or anti-depressive activity, that helps me concentrate when I 'm in stress...) (I wonder how Stephen Hawkins copes !)

And I imediately thought of that delightful comic-horror «The Adams Family», where the hand (called "Thing") had a life of its own, and went around to cause trouble... (as much as I can imagine a hand with no connection to a brain)

https://en.wikipedia.org/wiki/Thing_(The_Addams_Family)

CHESTERTON on the Theory of Evolution :

" It is difficult, no doubt, for us in somewhat subtler days, to understand how anybody could suppose that the origin of the species had anything to do with the origin of being. To us it appears that to tell a man who asks who made his mind that evolution made it, is like telling a man who asks who rolled a cab-wheel over his leg that evolution rolled it. To state the process is scarcely to state the agent. "

-----

G. K. Chesterton. A Handful of Authors: Essays on Books and Writers, New York, Sheed and Ward, 1953.

Lucy is much closer in behavior and intelligence to our close primate cousin that to ourself and since Lucy had already a  thumb opponency and was walking straight then I conclude that it was  a consequence of walking that free the hands into non-arborial environement where maybe a lot of things need to be carried around.  Our close primate ancestor have one neural map to control the hand while we have one neural map per finger.   The thumb greatly increase the mechanical potential for manipulating objects and so it also require more fine grain control to do so.   Living outside forests where all the fruits just need to be grasp and eat and branches always grabbed in the same ways is a very small space of manipulability than the space of manipulability that homonin could began to explore when they started walking with free hand with thumbs. At some point the hominin learned to use fire allowing them to cook and eat meat in greater quantity but for that they had to use some tool to cut meat out of large carcasse and eventually use pointed stick to kill animals.  But doing that require a lot more than the thumb, it require a lot of cognitive skill to exploit this manipulative space towards these functions. Preparation of the tools ahead of time, carrying them,, coordinating all these activities.  But we understand why doing these activities require planning cognitive skills but what is their nature and how exactly did they evolve.  IN the origin of the Modern Mind, Merlin Donald proposed a theory that is interesting.  I do not think that it is the whole story though.   I think that what is missing in it is the role of the empathy in the development of the mimetic consciousness.

We have to remember that the central nervous system of an animal, any animal is about moving its body engaged in an interaction.  This is true of all animal.  If an animal body can do only a very limited typical move and can perceived only a very limited information and interact in a small number of mode of action. Then the nervous system does not have much to do and if this interaction is perfectly adapted then there is no need, there is no place for more brain power.  What are the most intelligent animal in the sea.  The Cephalopoda have by their body structure a high manipulative space open to them and have a skin allowing them to camouphlage and communication through visual methods.  The space of expression and manipulation open by this body structure is very high and it is why it is necessary and possible to have high level cognitive resource that exploit these possibilities,  

See mammals have very similar bodies than the fishes that have much less complex nervous system.  See mammals do not live in the same manner than fishes.  They live in groups and act in group, fish in group, travel in group, take care of their young in groups and all these activities are very complex and require these mammalian brains.   Their individual body are as clumsy as that of fishes and individually is not open on a large manipulative space.  But in group, they form a single body with a very high manipulative space and this kind of group behavior require empathic understanding of each other for the coordination of their collective tasks which take place over long time frames.  

The mammalian brain allows cooperation and thus individual mammal bodies to act in some circumstance as collective bodies.  Primate are very advanced in making collective bodies but this is the key distinctive aspects of humanity.  We become humans through enculturation and enculturation is mostly about cultivating the participation in different social role, i.e. participating in different type of collective bodies.  We are the ultimate mammalian nervous system, the nervous system of a shape shifter that can thus through enculturation participate in an unlimited number of collective bodies whose genetic is culturally constructed and transmitted.

Thank you dear Louis ! 

Impressive. I have a problem with sea mammals. They do have 5 fingers and sometimes claws. But they are indeed clumsy . I wonder why... (probably as a result of body overweight, that they need to defend from cold waters.)

Maria,

They are individually clumsy because they can do all what they want to do (eating, swimming) with this type of clumsy bodies.  The Cephalopoda are mostly living at the bottom in very complex environment and do not swim much.  The agility of the sea mammal is a collective group agility when they hunt collectively and coordinate their bodies in nest structure and communicate with each other.

Communication and group agility is a form of intelligence. Isn't it ?

" Oh, the powers of Nature ! She knows what we need, and the doctors know nothing. "

----- BENVENUTTO CELLINI, Autobiography, 1558-66.