This is what I know about that. I'm pretty sure it's accurate.
All darker complexions (including the Olive skin tones of the Meditteranean) have *some* natural protection from damage done by the sun's rays.
That protection does NOT mean that darker skinned folks shouldn't bother with sunscreen. My husband, who is pretty dark in the winter, by the end of summer is BLLLLLAAAAACCCCKKKKK. And he wears 40 spf and a hat, etc faithfully. Therefore, I know he is still being exposed to harmful rays. I believe the way it works, if all things were equal, it may take a black person LONGER to get skin cancer (unless that person already had a history of moles etc running in the family).
Also, white people didn't used to get skin cancer because they avoided the sun. (80 years ago, it was thought that if you had a suntan that meant you were so poor you had to do your own outside work. Now, a suntan means you have enough income for a vacation or at least a tanning bed, LOL).
When I lived in Puerto Rico I always looked wierd, because I wore sunglasses. The Puerto Rican people for the most part never did. Now ask yourself, why does PR have one of the highest incidents of cancer of the cornea? The cornea itself is suceptible to cancer, which I didn't even know before I lived there.
So I think the answer is, darker complexions also are at risk for melanoma, and the risk factors are for the same as the lighter complexions.
Skin nevus, sun exposure, etc.