Source: The Official Handbook Of The Marvel Universe

A commonly used term for describing all superhumanly powerful mutant human beings as members of a new species.
Technically speaking, each superhumanly powerful mutant with a different power or set of powers from the others is probably a member of his or her own subspecies of Homo sapiens (Latin for "thinking man"). However, there is some evidence that all superhumanly powerful mutants have some characteristics in common that normal humanity does not share: for example, these mutants all emit distinctive psionic waves. There is also reason to believe that these mutants are the first wave of a newly evolving superhuman race