Quote Originally Posted by English assassin
I'm not giving up on sexual selection that easily. There's a pretty good argument that the truly freakish development of the human brain is as much due to sexual selection as the peacock's tail, and that occured in an environment of dangerous competition (eg lions) and imposes a huge energy burden on us.
The male lions' manes serve clear practical function - they protect the throat from hostile fangs. And how do about all the major competitors male lions can expect to fight against (other lions and hyenas mostly) primarily kill things ? By going for the throat. AFAIK aside from their reproductive duties (and fighting off up-and-coming male lions) one of the males' chief duties in lion prides is to act as the heavy artillery in the endless squabbles with the hyenas, which are wont to give way to the big lugs where they otherwise wouldn't.

The human survival strategy came to be based on cunning, communications and eventually tool use. That needs brains. Since it's also pretty workable, the brains kept growing. Duh.

As for the peacocks... well, males are more expendable anyways as far as reproductive strategy goes. Plus they obviously didn't have all that many critters after their heads, given the grotesque size the males' tails have reached. Their assorted cousins seem to generally favor lot less cumbersome methods of showing off.