In an interview with the famed Stan Lee about his history of creating characters he talked about the trouble of coming up with fresh and new ways that a person could gain their powers. Spider-Man gained his with a radio active spider bike, the Fantastic Four the cloud in space, the Hulk the gamma radiation and on the other side of the line Superman was an alien and stored energy from Earth’s sun, Green Lantern from his power ring, Martian Manhunter being a Martian. But what happens when you can’t really come up with even reasonably decent explanations? As Deadpool recently joked in his film, telling a comic buyer that your character was bitten by a “radioactive Shar Pei” would be laughable at best but more likely insulting. So how do you keep it fresh? Stan simply decided to have characters born that way and with that thought and in 1963 Marvel’s X-Men where born. DC and Wildstorm also followed suit with terms of their own, DC Comics’ being the term “Metahuman”.
The term Metahuman was introduced in the DC Universe was first used in “1986 by author George R. R. Martin, first in the Superworld role playing system, and then later in his Wild Cards series of novels.” per the Wikipedia entry. In the Marvel Universe the X-Men are Mutants, an evolutionary step forward for the human race and ONLY applies to those people that have the genetic make up of the so called “Homo-Superior”. Conversely the term “Meta-Human” is used in the DC Universe to describe any powered individual retroactively applying to Superman, Martian Manhunter, Aquaman, and even Wonder Woman. First used by an alien race during an invasion of Earth the descriptor used from the stand point of “meta-” meaning “beyond”, denoting persons and abilities beyond human limits. This different is quite different than the Marvel “mutant” concept and is the main distinguishing factor between the two terms however there is a genetic component to having existed for centuries so the while the terms are not synonyms they are not dissimilar.
According to Countdown to Infinite Crisis, there are roughly 1.3 billion metahumans on Earth, 99.5% of which are considered “nuisance-level” while only 0.5% are considered to be in one of three categories “Alpha”, “Beta”, or “Gamma” such as the main members of the Justice League. (Superman and Wonder Woman being prime examples of Alpha Metahumans.) For comparision, Marvel doesn’t provide numbers as exact as that previously mentioned for Meta Humans however the official Marvel.com page for mutants states the following: “With a species-population numbering in the millions… it appeared that over time, mutants would eventually supplant humans as the dominant species on Earth.” However after the events of “M Day”, a comics event in which the Scarlet Witch, herself the mutant daughter of Magneto, uttered the words “No More Mutants” and wiping the world of Mutants but was later partially restored, the estimated world wide population is “now estimated to be in the hundreds”.
With the release of Batman vs Superman: Dawn of Justice and its inclusion of not only the title characters but also Metahumans like Wonder Woman, Aquaman, the Flash, and Cyborg and its obvious base as point zero for an expanded DC Comics Cinematic Universe, the Wonder Woman film already well into production, its important to know and understand the use of such a niche term. Understanding the term Metahuman in comparison to Marvel’s Mutants is also important because the nuanced differences could be over looked by the fact that there are five main line X-Men movies already released,a fourth around the corner, not to mention the spin-off movies like the two existing Wolverine, third Wolverine in production, and recently released Deadpool movie, and so the term Mutant and its meaning are well known vs the lesser known ‘metahuman’. While tv shows The Flash and Arrow, on the CW, are using the term much more today expect to see it even more in the future with DC/WB planning releases over the next 6 years.