From what I have learned being a pre-med student is that we used hair as a way of trapping in heat and yes we do not have as much as a rabbit but it did the job and thats why we are getting less hairier and the hairs on our extremities are thinning. For men and their beards I read that it actually provides antimicrobial properties in a way our nose hairs do and that it traps bacteria before entering mouths. :o I see it as just a natural adaptation and its just part of our bodies and I don't see it as a fashion trend or anything.
I told him that when our bodies don't need the hair it will go away on its own, evolution will eliminate the trait. But he insists that it's a leftover and that technology has all the needs hair would provide for covered.
I told him that if we bypass the body and use technology invented by us instead of the tech our body created, then if this new tech becomes absent our bodies will be exposed (many generations ahead). What I fear is that we are making ourselves more vulnerable. His response was that if we ever come to need hair again evolution will bring it back...
I understand where your coming from and that if we lose it then what happens if we need it later? I don't think its leftover but I think it is slowly becoming less expressed because we have adapted to different climate and etc. I don't know about evolution bringing back a trait such as hair but I think were not completely eliminating it. I guess we won't be too sure until further in the future and compare :)
It's not a leftover, it helps with everything from climate control to impacts and even bugs. Some men even go as far as to attribute emotions to its presence, saying they feel more centered and calmed. But that last thing may be because of the cleaner air and the healthier skin ;)
It may be a leftover compared to how much we had before, but it still has many reasons to be and that's why it's still there.