Old men, eyebrow and ear hair

Apologies in advance if this has been asked. A quick search turned up nothing.

I have just finished watching 60 Minutes. Andy Rooney’s eyebrows are out of control. From my brain to the message board… what causes eyebrow and ear hair growth to kick into overdrive the older men get? Can there be any evolutionary purpose? (Other than to make people sick to look at, I mean)

It can’t just be years of ignored growth.

I guess another question could be why don’t old guys trim their eyebrows and ear hair, but I assume the answer has somthing to do with not giving a shit anymore.

Thanks,
Max