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nervous system development

Discussion of everything related to the Theory of Evolution.

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nervous system development

Postby narrowstaircase » Thu Nov 02, 2006 5:12 am

the development of the nervous system in anamalia is evident. from insects through fish, amphibians and reptiles to birds and mammals the nervous system has developed into a larger brain to manage the lives of the organisms better. (is this self evident to you guys?)

well i was wondering what you guys think of this. is this evidence of orientation in evolution? what do you guys think of the idea of development (direction in evolution)?
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Postby sachin » Thu Nov 02, 2006 5:19 pm

You are right.
But its not that evolution is unidirectional. Evolution have tried all possible ways to change organisms acc. to evironmnt. Evolution is phenomenon happening due to changing env.

Brain size :?:

Then tell me why reptiles like "monitor lizard" have much bigger brain than cat (Felis domesticus) :wink:
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Postby narrowstaircase » Thu Nov 02, 2006 11:37 pm

thanks for answering sachin

i see the flaws you pointed out. what if i meant to say the sprouting of the classes from the tree of life saw the arrival of bigger brains :lol: didnt dinosaurs have brains that were just nodes on the spinal column?

if smaller brains were investigated by evolution and only larger brains have developed isn't that still unidirectional?

monitor lizards are bigger than domestic cats and dont have an efficient brain either which accounts for the bigger size. (im guessing, i havent studied it) does anyone know whether a cat has more complex behaviour than a monitor lizard? my cat is more affectionate i can guess.

what do you think of this sachin?
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Postby nugget » Thu Nov 16, 2006 7:21 am

Another thing i think restricted the simpler organisms from continuting to develop more complex brains and nervous systems would be the fact that a lot of invertebrates have their main nerve fibres and related ganglia as a ring around their pharynx. Now u can imagine brain development may be restricted if it surrounds your throat basically.

I think the brain is quite important as is intelligence. Just look at the cephalopods --- the Octopus are very intelligent and show excellent examples of learning and memory. I think the size of the brain and its structure - more importantly is what allows for many more learning pathways to be developed, theres more room and the connections of the neurons might be more efficient in more sophisticated organisms which make them that way. Like you could havea big brain and lots of nerves but if they are not connected efficiently with functional lobes then i guess it defeats the purpose?
I dont know either but the monitor may have the right "wiring" to manage its metabolism and maintain its large body size, according to its lifestyle. A cat on the other hand, doesnt have similar habitat, feeding or reproductive lifestyle as the lizzard. They may need some learning and some memory or \perhaps because they have beendomesticated for a while it might account for their affection which may be a result of a mesh of factors.

We could do some neat experiments on that hey :P

bigger brains doesnt mean better way of living. it was probably chance and allows a more sophisticated form of life. like our ones... yes much better we have bigger brains for bigger worries :lol:
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