Welcome to
Science a GoGo's
Discussion Forums
Please keep your postings on-topic or they will be moved to a galaxy far, far away.
Your use of this forum indicates your agreement to our terms of use.
So that we remain spam-free, please note that all posts by new users are moderated.


The Forums
General Science Talk        Not-Quite-Science        Climate Change Discussion        Physics Forum        Science Fiction

Who's Online Now
0 members (), 181 guests, and 2 robots.
Key: Admin, Global Mod, Mod
Latest Posts
Top Posters(30 Days)
Previous Thread
Next Thread
Print Thread
#4927 12/15/05 03:54 PM
Joined: Dec 2005
Posts: 49
Y
y Offline OP
Member
OP Offline
Member
Y
Joined: Dec 2005
Posts: 49
What are the current theories re: the evolution of the human brain.

do we use all of its capacity?
if not why has evolution given us this added capacity which is not used?

does evolution think ahead?

Any views eagerly awaited.


If you want to get to the top of a hill (and your very fit), the Grand Old Duke of York is your man. y


y
.
#4928 12/15/05 04:04 PM
Joined: Jun 2005
Posts: 1,940
T
Megastar
Offline
Megastar
T
Joined: Jun 2005
Posts: 1,940
"does evolution think ahead?"
No. Evolution proceeds towards local minima. That's why some features of organisms can be non-optimal.

In artificial systems, there are ways of ameliorating these effects. I'm don't know whether there's a biological equivalent to something like simulated annealing. (Although it's possible that some hormones might serve that kind of purpose.)

In any case, even if it's true, it's just a way of reducing the effects of not being able to see ahead.

#4929 12/15/05 04:22 PM
Joined: Dec 2005
Posts: 49
Y
y Offline OP
Member
OP Offline
Member
Y
Joined: Dec 2005
Posts: 49
WHoa, Whoa, ney Whoa!!!!
thasorus alert, i'm only 7 years old.

Please note i am not a scientist, just an interested medler, assume my scientific vocabulary is minimal.


y
#4930 12/15/05 05:55 PM
Joined: Jun 2005
Posts: 1,940
T
Megastar
Offline
Megastar
T
Joined: Jun 2005
Posts: 1,940
Evolution does not think ahead. It doesn't have anyway of looking ahead.

At any given moment in time a collection of organisms (a species) exists in an environment, of which that species itself is a part. Those organisms will eventually produce far more offspring than the environment can possibly support. Example: you can't support 10 elephants on one acre of land.

So, this population is subject to selective pressure. Not everybody can live long enough to reproduce the next generation. But there's another fact. Whenever organisms reproduce - make babies - there are errors in the copying process.
Most of the time these errors are detrimental. Sometimes they even prevent the organism from being born. But some very few times, they give that particular organism a strong advantage compared to the others. For example, it might make him bigger. This might be bad for him, if he can't get enough food. Or it might be good for him if it makes him able to steal food from the others.

The "best" qualified do not always survive. Sometimes the weaklings live. The process is not perfect. But, on average, the creature that is best adapted will have a better chance to live long enough to himself reproduce.

The process doesn't work on what will happen, but only at what is. Example, it could be that being 1/4 inch taller is a disadvantage in a given environment because it requires you to eat more, but doesn't give you the ability to get more food. However, maybe if you were 3/4 of an inch taller it would be worth it, because then you'd have an even bigger requirement, BUT you'd also be able to get the food you need (improved hunting, or improved stealing, etc). But the organism won't get to the 3/4" (unless it does so on a single jump) or unless there's some other advantage to get it past the problems of being only 1/4" taller.

#4931 12/25/05 07:33 PM
Joined: Oct 2005
Posts: 560
R
RM Offline
Superstar
Offline
Superstar
R
Joined: Oct 2005
Posts: 560
"does evolution think ahead"
Y,
I think you would enjoy a book called 'does anything eat wasps?' It's a collection of 101 interesting Q&As from the 'NewScientist' magazine.
"if not why has evolution given us this added capacity which is not used?"
Some say it IS used, in times of mortal danger etc... However, there is no proof. It makes sense though.
I suppose if intelligent people keep breeding with eachother, the end product would be a human with a brain with the capacity to do a lot. However, the surroundings of the human may not require them to use it, and so, they live and die without ever knowing of this potential, or using it.

P.S. I remember reading somewhere that it is actually BAD if an organism evolves a brain more advanced than is needed. I can't remember exactly why, but I think it was someting to do with having to provide more nutrients for it, even though it's not using it.


Link Copied to Clipboard
Newest Members
debbieevans, bkhj, jackk, Johnmattison, RacerGT
865 Registered Users
Sponsor

Science a GoGo's Home Page | Terms of Use | Privacy Policy | Contact UsokÂþ»­¾W
Features | News | Books | Physics | Space | Climate Change | Health | Technology | Natural World

Copyright © 1998 - 2016 Science a GoGo and its licensors. All rights reserved.

Powered by UBB.threads™ PHP Forum Software 7.7.5