Mutations, Evolution, and Super Suffusion

Over the long course of Earth's history, life has slowly evolved through a series of random changes to the genes of offspring. Humans are not exempt, despite how much they wish to believe they are.

As the years flew by, humans have become slightly more social, emotional, agreeable, maybe just a bit dumber, are more prone to severe mental breaks, and have a higher chance of spontaneously combusting (chances are low, but never zero), among other small changes.
These all pale in comparison to the mythical X-Gene -- the (probable) next step in evolution -- and the steady appearance of what people refer to as 'the mutated', which then paved the way for superpowered criminals, millions of taxpayer dollars in property damage, and "those who take the law into their own hands" (as J. Jonah Jameson would say).

A gene that can grant stars-damned superpowers! It sounded straight out of someone's dreams... or a bad drug trip; it depends on who you ask.
Not everyone was pleased with this new change, however. Humanity fears reality and being left behind by the ever-marching future, claiming the mutated are 'deity wannabes' or some reincarnation of demons.

These individuals fail to acknowledge that the meek shall inevitably inherit the Earth or die trying.

Notable Mutants

The X-Gene

The X-Gene! The next step in human evolution, scientists proclaim. It's unclear when exactly this gene made its appearance (both by itself and within a mutant), but it's assumed to have been one of the first DNA strands formed in the midst of the Hadean Era.
There are records from prehistoric times alluding to the appearance of mutants on every corner of the globe. However, it's unsure if those artifacts actually confirm the existence of mutants or are simply pieces of mythology/holy scripture.

How the X-Gene operates is a much more difficult question; it branches away from biology and into the unholy realms of quantum physics and cosmology -- beyond even the most insignificant of quarks; the stretches of nothingness that flicker in and out of existence that somehow make up the very foundation of reality itself -- it's not something humans enjoy talking about.
In fact, it is quite literally impossible to study the X-Gene in any capacity. The senses get overloaded with information before shutting down. The scientists observing the gene (not limited to sight) either have their lives siphoned or they experience something that could only be described as pure insanity.

It's as if the X-Gene were classified; as if it were a parasite; as if something was guarding that information.

It's downright illegal to observe how the X-Gene functions on all landmasses because it's not a risk, but a death wish.

Tolerance is Extinction

The question of what humanity's greatest fear could be is as old as humanity itself.
Who knew that this and the question of humanity's greatest hatred share the same answer; the unknown?

The X-Gene is one of life's greatest mysteries; a code that refuses to be cracked. Thus, in the face of what cannot be known -- the permanently unknown -- humanity cowers and snarls, flees and raises pitchforks, and equates those who are bearers of the great unknown with that of damnation. It wouldn't be far-fetched to say that holy scripture is blatantly contradicted by deeming the X-Gene to be a travesty of the Stars.

The one mistake and uncertainty in a Universe where people cling to the idea of superdeterminism and fate like it's a lifeline was the curse that befell upon the mutants. A stars-forsaken product of the unknown future.
The humans fear the unknown; the future is also feared by extension.

To wither from true glory into nothing but remnants of the past due to the unstopping march of time -- if they're lucky. To spiral into nothingness; to have all of their efforts go to waste because of an inevitable biological process; to be nothing but products of time. Out with the old; in with the new.
Thus, to accept the mutants who grovel at humanity's boots for mercy was naught but complete and utter extinction.

Spot the Difference

The difference between humans, mutates, and mutants is determined by three factors:

• The presence of the X-Gene
An absent X-Gene immediately disqualifies someone from being a mutated individual.
• Whether or not the X-Gene has ever activated
An X-Gene that's never activated (excluding those who have had their activated X-Genes nullified) disqualifies someone from being a mutated individual.
• How it activated, if applicable
An X-Gene that activated without the influence of external stimuli would qualify the bearer as a mutant. If the X-Gene was activated in response to stimuli, they'd be a mutate.

The X-Gene presents itself differently in every featherless biped.
Sometimes, it follows the typical path of manifesting during one's preteens, but it may also activate in early childhood or near the end of one's life. Regardless of when in someone's life the X-Gene manifests, they would be considered a mutant -- Homo superior. It's important to note that the X-Gene does not activate in response to strong emotions, such as panic attacks or fits of rage, but simply appears at random naturally.

Other times, someone bearing a dormant X-Gene is activated in response to an event that can translate to abrupt mutagenic change (emotional distress, artificial/Cosmic interference, etc.), which would consider this individual to be a mutate -- Homo medialis.

Mutate examples: Virgil Voltspun (spider bite), Wade Wilson (human experimentation), Sanya Snezhana (self-inflicted genetic modification).

Someone that either has a permanently dormant X-Gene or simply lacks one is just considered to be human -- Homo sapien.

Human examples: Barika Bushara, Quentin Beck, Gwendolyne Stacy.

Super Suffusion

A phenomenon has popped up in recent years of quite a large number of the mutated (or regular humans with specialized equipment) going out and using the abilities they inherited from the X-Gene to commit crimes -- superpowered criminals, the news tabloids tentatively dub them.
On the contrary, there are also a large number of the mutated going out and using their abilities to stop the crimes committed by these superpowered criminals -- they're mostly designated as supers. (...Or vigilantes, for the more skeptical, but that title doesn't technically apply to all supers.)
People, aside from diehard super fans, throw their hands up in the air and call everyone with superpowers just doing something to affect the city -- good or bad -- a super. It's easier that way.

Now, Super Suffusion is the moniker people gave to the gradual appearance of supers (those who wish to help, commit crimes, or be somewhere in the middle). Despite the X-Gene being around for millennia, supers themselves have been noticably absent until after a group of people stopped Ultron in the late 2700s -- with Dr. Pym being in the forefront in terms of inspiration. The absence could possibly be attributed to extreme anti-mutant laws and points of view that reigned across most of history.
There are approximately 26,000 supers worldwide; most of them (~6,000) reside in the United Republic -- which granted it the title of the Superhero Capital of the World -- to rather mixed reception and advocacies for new regulations to be implemented that restrict the freedom of these individuals... Overall, it's a mess.

Trivia

• In databases, a mutant/mutate's original species must be specified (e.g., "human mutant") for the sake of recordkeeping; just in case the X-Gene extends to non-human organisms.
• Supers are rarely referred to as superheroes (except by children or if the super in question is highly famous, like the Avengers) as a super's motive and moral compass are definitively known, especially if secret identities are in play.