Why is man the only animal whose hair keeps growing?

[Bonzi]

The hair on animals stops growing at a certain length. Even on their heads

The hair on a mans head and face continues to grow. But hair on arms and legs stops growing.

Did prehistoric man have hair down to his knees?

Dogs hair keeps growing, I think, some breeds anyway....

 

[RWS]

My nose hair is now turning gray. That sucks...

I have no idea on how to check on my ear hair....

But my pubs are nice and brown!

TMI. Nobody wants to hear about your "pubs," bub.

Apparently you do. And now you know the answer...

Question is, why?

 

[RWS]

The hair on animals stops growing at a certain length. Even on their heads

The hair on a mans head and face continues to grow. But hair on arms and legs stops growing.

Did prehistoric man have hair down to his knees?

Dogs hair keeps growing, I think, some breeds anyway....

Doesn't keep growing my friend, it grows to the length that it is made for, and then falls out.

 

[RWS]

Can you imagine women with long hair, and armpit hair that doesn't oblige to it's regulatory size?

I mean geez, if armpit hair and head hair grows at the same rate, then that would be scary!