This X-Men fan theory suggests that Caesium 137 is what caused the overpopulation in mutants after WWll.
Let me know what you think of this theory in the comments!
Social Media:
linktr.ee/swappin.thoughts
Timestamps:
0:00 - Intro
0:08 - Original X-Men plan scrapped
0:28 - The X Gene
0:50 - Caesium 137
1:15 - THEORY