I posted this in an existing thread, but I thought it important enough to give it a thread of its own.
There might be a way to easily find out if repeated plucking of hairs over many years results in permanent hairloss.
Simply examine case histories of people who have trichotillomania or hair-pulling disorder.
According to Wikipedia ( http://en.wikipedia.org/wiki/Trichotillomania ), such people with this disorder can suffer permanent loss of hair.
Which may support my hypothesis that a follicle can only regrow hair a fixed number of times.
Or if my hypothesis is incorrect, it might be that repeated pulling out of hair eventually does permanent injury to follicles (scarring alopecia).
Either way, it would seem wise for physicians to pull most of the hairs from a different small donor region for each pull-and-plant session, to avoid pulling hair from the same follicles more than once.