I can think of absolutely no reason for going bald. It seems to me that I should have hair on my head to keep myself warm in the climate I live in.Bear in mind my freinds that even the eskimos, who have lived by some accounts for 30,000 years in their climate (cold) also have baldness.

even wool mammoths got thinning hair as they grew older.Er...wool.

You are past your mating prime, and so women need that signal.If you don't have a woman to make you cap, you will die of exposure.

Evolution can't completely explain it because humans kind of screw up the whole process sometimes. I think your answer is that historically a larger forehead (within reason, of course) was seen as a sign of intelligence.

It is probably a side effect of another selective advantage. For example too much testosterone (DHT to be more specific) can cause hair loss. The excess testosterone may have been the selective advantage. For a more improbable explanation, maybe losing your hair makes it harder for your enemies to grab you by the hair and scalp you.

your body knows you don't need as much hair as man did in caveman days hence the balding.........

As time goes on, man has adapted with things such as duller and fewer teeth in our mouths, less hair everywhere on our bodies--that's why we only have hair on our heads, armpits, and pubic regions. It's why a lot of men have developed "male pattern baldness". And it's why more and more of us are not growing "wisdom teeth", or why we only have two. It's such a slow process that it's almost un-noticeable! But isn't it a wonderful thing?! I don't know why everyone is so afraid of it, except for ignorance!!