Skin is like a conveyor belt. The conveyance begins at the lowest level (stratum basale) and moves upwards until it reaches the surface (stratum corneum). The stratum basale is also where dermals originate in the skin. The stratum corneum is replaced via shedding of the dead surface cells and is replaced via new cells pushed up from the stratum basale.
Cliff notes = High friction areas would develop calluses over time but lower friction areas would continue to show dermals despite occasional friction via replacement of skin cells.