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Author Topic: Evolution of the brain  (Read 4092 times)

Offline DoctorBeaver

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Evolution of the brain
« on: 24/05/2005 12:41:31 »
I've often wondered if dogs' amazing sensitivity to smell (or other animals sensitivity to other sensory input) has been a hindrance to them developing into more intelligent creatures. In the case of dogs, not only is their brain smaller than humans but much more of it must be taken up by processing olfactory (and audio) input. Did the structure of their brain develop deliberately to have that degree of sensitivity or did that sensitivity evolve as a result of the way their brain evolved? My gut feeling is that it's the former & that its development along those lines stopped development in other ways.

Is there any evidence to show that humans ever had greater sensory sensitivity than they now have?


 

Offline daveshorts

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Re: Evolution of the brain
« Reply #1 on: 24/05/2005 13:11:20 »
I think it is more to do with what is evolutionarily a good idea, brains are very expensive things - our brain uses up something stupid like a third of the oxygen we use which for 2% of our body weight is quite proflegate - so species will only evolve more intelligence if it is benificial to the individuals concerned. Hominids were really quite unsucessful until probably homo-errectus, which is why they are so hard to find fossils of.

So it is in the interests of a wolf to be just bright enough to survive, and a good sense of smell is probably more useful than musical ability...

I suppose that as the resources are already committed to smell decryption there are less left over for other purposes, and possibly more importantly if a lot of your communication is by smell, the words are in hardware rather than software as it were so you can't invent new words and language is more difficult to develop...
 

Offline Andrew K Fletcher

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Re: Evolution of the brain
« Reply #2 on: 24/05/2005 16:23:04 »
There has been a great deal of work into the development of the brain. Dean Falk and Michel Cabanac have published paper on the location of small holes in the skull and have been involved in researching selective cooling of the brain (The Radiator Theory) It appears that the holes in the skull, have migrated to the top of the head after humans became upright. They add that this additional cooling capability gave us an advantage over the less upright hominids, comparable holes are found in apes, located at the rear of the skull. Cabanac was involved in researching a 2 directional flow of blood through the brain. He observed that blood can flow back against the pressure of the heart, when the body becomes overheated due to exercise. Demonstrating this with a doplar probe. This also suggests that the circulation inside the brain has changed, and maybe this has added some additional order in the way the brain has been assembled; maybe an equivalent organic computer upgrade resulted in the newly redirected order of circulation, which changed the way we perceive our environment and interactions with each other. After all, we appear to be the most upright. Is it a coincidence that we are also the most dominating and prolific of all species? But what does this tell us about the origin of circulation in the brain and central nervous system?
 
Andrew


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Offline DoctorBeaver

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Re: Evolution of the brain
« Reply #3 on: 24/05/2005 17:50:12 »
Dave - that's basically what I meant. The brain developed in ways that suited how the animal needed to behave to survive.

Andrew - That's interesting about the holes & blood flow.
As for being the most upright, I was under the impression that this came about to give humans a range-of-sight advantage over less upright animals. There are quite a few instances in nature of animals making themselves taller by standing on their hind legs: usually when looking out for danger (meerkats are probably 1 of the best known). Even some antelope rear up on their hind legs when they're on look-out for the herd. My Jack Russell also does it when I take her into a field of long grass looking for pheasants.
 

Offline Andrew K Fletcher

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Re: Evolution of the brain
« Reply #4 on: 24/05/2005 18:05:43 »
I accept what you say as a logical conclusion to why we stood up. However, I was refering to what happened to our brain after we stood up and how that is affecting our evolution at present  

http://www.ceptualinstitute.com/genre/falk/falk.htm :D

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« Last Edit: 25/05/2005 09:40:22 by Andrew K Fletcher »
 

Offline DoctorBeaver

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Re: Evolution of the brain
« Reply #5 on: 24/05/2005 23:14:20 »
Oh dear. I think Andrew may find himself in trouble:D
 

Offline chimera

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Re: Evolution of the brain
« Reply #6 on: 25/05/2005 00:31:16 »
Oh nice one. Next thing you know tomorrow morning this forum reads 'UltraPurple Hackerfront ownz your server', and Andrew is ip-traced back to his flat and will be found with his head stapled to his monitor, talk about holes in your skull and improved bloodflow gosh...

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Offline DoctorBeaver

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Re: Evolution of the brain
« Reply #7 on: 25/05/2005 00:52:28 »
heh :D

It wasn't me - a big boy did it & ran away
 

Offline Andrew K Fletcher

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Re: Evolution of the brain
« Reply #8 on: 25/05/2005 10:48:33 »
I take it the picture was in bad taste, sorry if it offended anyone, but I thought it was funny at least, must be my Midlands sense of humour, anyway I've moved out of my flat and ditched the staple gun.

But seriously, the position of the holes in the skull is relevent to this discussion and Falk's site is an interesting read, so are Michel Cabanac's papers on reversed blood flow in the brain.

http://www.albany.edu/braindance/Theories.htm   Falk's

http://p2222.nsk.ne.jp/~ntetsuo/BC95.htm Link to publications relating to brain cooling

http://www.anthro.fsu.edu/people/faculty/falk/radpapweb.htm

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« Last Edit: 25/05/2005 10:54:48 by Andrew K Fletcher »
 

Offline chimera

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Re: Evolution of the brain
« Reply #9 on: 25/05/2005 12:22:54 »
quote:
Originally posted by DoctorBeaver

Is there any evidence to show that humans ever had greater sensory sensitivity than they now have?



I know some developments are possible, but they are on the 'edge' of what we can already perceive, like with polarised light, like pigeons. Some humans see that automatically, and most will pick up the trick when shown how.

So, like with hearing, we can see things but not be actively aware of it. If you (as I think you know better than me) take for example the fish-eye distortion of the eye, and how our brain turns that into 3d, or how we only update our view 10 times a second, and not 300 times like a fly - who would get very bored watching a movie btw - its mostly black to him. Watch clouds at higher speed on video and you don't believe it's the same process - you suddenly see stuff that you normally don't because it's happening too *slow*, and you feel like some silly toad that cannot see something if it doesn't move fast enough... yikes.

I think there's a general huge discrepancy to what our senses can actually pick up and what we 'make' of it, or even what we 'want' of it.

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Re: Evolution of the brain
« Reply #9 on: 25/05/2005 12:22:54 »

 

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