This has been kind of bugging me lately. But I am confused on how exactly the X-Men fit into the Marvel Universe. To me it seems they are from a universe where humans are evolving and gaining abilities after puberty and called mutants but in the actual Marvel universe the characters gain their abilities by accidents or experiments and they are called super heroes or villans. So somehow they exist in the Marvel universe but it would seem that everyone would have abilities or powers then. So anyone know or do we just assume?