The Marvel Cinematic Universe post Avengers Endgame is set to be bigger and better than ever before with an unlimited amount of characters to be introduced. It’s no mystery that the Mutants and X-Men are one of many characters to soon make their MCU debut, yet people may be wondering how they’ll come about in the first place and where have they been all this time? Well the answer is: they didn’t quite exist yet. That was until Thanos snapped those big purple sausage fingers however.
The Mind Stone Created Wanda and Quicksilver:
For context, in the mid-credit scene for Captain America: Civil War we’re introduced to a group of Hydra scientists who have used the mind infinity stone to create people with powers, those being Quicksilver and Scarlett Witch. It’s believed that the stone activated their powers that were within them and without us even knowing, this was the the activation of the mutant gene. However, they obviously couldn’t mention this at the time as Disney had not yet owned the rights to the mutants.
Thanos’ Snap Created The Mutants:
Now if we fast forward to Avengers: Infinity War, Thanos has collected all of the infinity stones and snaps his fingers wiping out half of all living things (spoilers). In Avengers: Endgame Rocket then goes on to explain that when Thanos snapped his fingers, earth became ‘ground zero’ for a huge amount of cosmic energy that no one has ever seen before, even a Racoon from outer space hadn’t seen anything like it. It’s likely that the very same cosmic energy is what created/activated the Mutant gene in human beings all over the planet.
It’s A Solid Theory:
The cosmic energy that covered earth is from the stones, including one of the stones that activated Quicksilver and Scarlett Witch’s powers. It’s also important to remember that two more snaps happened afterwards, from both Hulk and Tony Stark meaning all of that cosmic energy has had to have some sort of impact on the earth and the people living on it.
It’s extremely likely that the result energy of the snap has created or activated the mutant gene inside a lot of human beings. It makes sense as to explaining why the X-Men and Mutants weren’t seen or known about before which ties the MCU and it’s events together rather nicely. It also effectively means that Marvel have been setting up and teasing the mutants and X-Men for a very long time without trespassing legal restrictions, sneaky stuff guys.