In American comic books published by Marvel Comics, a mutant is a being (usually otherwise human) who possesses a genetic trait called an X-gene that allows the mutant to naturally develop superhuman powers and abilities. Human mutants are considered to be of the subspecies Homo sapiens superior or simply Homo superior, an evolutionary progeny of Homo sapiens, and are considered the next stage in human evolution, though whether this is true or not is a subject of much debate in-universe.