The frontal 1/2 inch of the male mature hairline is genetically different (photo)

Here is a good picture of a man with a persistent frontal hairline which shows hair in the leading edge of his hairline despite a bald head behind it.  It have seen these Persistent Frontal Hairlines exist when they are so strong, that the man can grow the hair long enough to make it look like a full head of long hair (a Comb-back is like a Comb-over just front to back rather than side to side)