I am with Rahven in this one, I think intra-specific competition (i.e. both sexual and social selection) is what ultimately drove us to have the brain we have today. This is true for almost all "extravagant" organs in nature, do silverback gorillas "need" all that muscle? Do caribous need those huge antlers? Do birds of paradise need such extravagant feathers? All of those are are under selection by competition either between males or between individuals.
This could passably be the best answer probably not the only one, even if the brain power could not be fully utilized, the brain that could come to solutions faster would be the one selected for even though there was not allot of basic knowledge the brain could deduce from like we have in the present. The more "space" the brain had to store real world scenarios, the easier it was to store and more data was available to process.
But you're still trying to find a need to fill for a positive selective pressure towards bigger brains. The point was that there might not even be that need there in the first place.
Oh yes... all those ladies thinking 'damn... can't wait to squeeze out one of his big-headed babies!'
That assumes they associated pregnancy with sex... I wached Pururammo the other night and those tree people in New Guinea still don't.
On a more serious note: What traits do you suppose would have been the selected-for traits that only consequentially led to a more powerful brain?
The same kind of shit chicks still fall for today: creativity, cleverness, comedy, art, you know...
Not that that's the be all end all. Honestly, I bet its a result of a very convulated response to a wide variety of factors that cannot be pinpointed as being a result of "this".
My point was to show frako that looking for a need to fullfill for the positive selective pressure to act on, and then failing to come up with one, shouldn't really lead him to think that it would be some difficulty for evolution.
Start paying more attention to the Republican candidates for US President. You might change your mind on whether the brain is overpowered.
You can buy your grandma the best PC out there if she does not know hot to turn it on its useless to her.
Our brains are seriously powerful compared to our closest living relatives especially if you "train" your brain to do certain tasks like fast reading some people can read a page as fast as some can read a word, or calculate high numbers, deduct something from abstract examples, photographic memory, ability to learn several languages i think the world record is 58 languages spoken fluently....
Christianity, One woman's lie about an affair that got seriously out of hand
Breasts? Testicles? I'm not sure what you are thinking of here.
I call it the Percy Theory of the Three B's: brains, boobs, and boners. They drove human evolution by way of sexual selection. Boobs and boners are about sexual attraction, while brains are about increasing socialization abilities and the resulting improvement in sexual opportunities. Physical and social qualities determine who is desirable (dominant), and those best able to wend their way into the hearts of desirable partners contribute more of their genes to succeeding generations. The most successful are also the most dominant. Human brains, boobs and boners are all the result of a positive feedback relationship between physical and mental qualities and sexual selection.
I haven't had time to vet my theory in the scientific arena, but I'm sure it's correct.