What bothers me about the evolution of Man

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.

Start paying more attention to the Republican candidates for US President. You might change your mind on whether the brain is overpowered.

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.

The human brain uses a lot of energy. It requires a lot of feeding.Without any positive selection pressure it seems unlikely that such an "expensive" organ would evolve purely as a side product of other factors in the way I think you are suggesting.That might be how it started out. But some sort of selection for bigger and bigger brains does seem to be required to explain the result we have ended up with.Sexual selection seems a viable candidate. Big brains are sexy.

That assumes they associated pregnancy with sex... I wached Pururammo the other night and those tree people in New Guinea still don't. 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.

There are several areas of human anatomy that are larger than average for mammals (proportional to our size), and I believe they're all primarily due to sexual selection.--Percy

Such as?Breasts? Testicles? I'm not sure what you are thinking of here.

Ok, I hope this does not break any forum rules, but here: the human penis is the biggest of all the ape species in length and girth, both in absolute terms and as a proportion of body size.

Looking this stuff up. Apparently the human penis is the biggest of all the ape species in length and girth, both in absolute terms and as a proportion of body size.So it seems creativity, funniness and other such brain related issues (that this thread is directly about) are a way of adding metaphorical inches.....

Haha, perfect! Or maybe we have a big brain to try to convince them that size is not all that matters!

And "they" have evolved big brains to see through these futile deceptions.Let the cock waving begin.....

The same goes for the peacock tail... they don't need it, it resulted from other selective pressures. That's what I'm talking about. But females can't see the males' brains directly, so there must be some other thing, that big brains goes along with, that the females would be selecting for.That's what I was trying to get at.We don't have to speculate about what kind of need for a big brain there is to select for.The OP reads as asking why the brain is so big when we don't need it to be like that. I'm saying that's the wrong question.

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....

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. --Percy

One thing to remember is that what we see today are only the nearest relatives left, those that did not pose a serious threat to modern humans.