Is There an Evolutionary Reason for Losing Hair at Certain Ages?

Hi Doc,

I have been wondering, what if any evolutionary reason was there for males going bald at as early as their 20’s and a lot more during their 30s and 40’s?

My speculation is that this trait becomes apparent well after puberty and sexual maturation, therefore it does not affect the passing of the genes. Do you have any thoughts on this?

I’m not sure of the evolutionary reason for going bald, but genetic balding can start at any age. The hair follicles have a programmed ‘death’ date and it is triggered by the hormone dihydrotestosterone (DHT) when the date comes to pass. Blocking the DHT with finasteride (Propecia) can delay the start date. Balding can come from either the mother or the father’s side, and very rarely does one see balding prior to sexual maturation, unless it is a variant of a genetic malformation.

There are case reports in family lines where complete hair loss starts at about 2-3 years of age. A family group has been studied in Pakistan where this genetic pattern is widespread in a particular town. The triggered age seems to be about 3 or 4 years old and unlike male pattern baldness, this is far more extensive balding, so it is clear that when there is a gene for some time or balding that is expressed, it is age triggered.