Last I read, mutants were caused by genetic manipulations of Earth's primitive populations by the Celestials, million years ago.

Considering that according to current calculation, the time to most recent common ancestors for all humans alive today is just around 2000-4000 years ago, and that Homo sapiens (of which Homo sapiens superior is only a sub-species) only appeared on the planet 0.5 million years ago, any characteristics introduced into the population over a million years ago would be evenly distributed over the entire population; including the potential for omega level and other-less-than-omega-but-more-powerful-than-most-'normal'-mutants mutations (aka the X-Men)

That means population wise, if there are X mutants or just X mutants with X-Men level powers in the US alone, there should be about 20X mutants (of that power-level) over the rest of the world - about 4X in India and China each alone, plus all the rest of Asia, Africa, Europe, the rest of the Americas (Australia should have only around X/10 though, so the around 3-ish in canon is mostly not too far from the expected!)

But they clearly weren't there, even pre-M-Day.

So, my question is: Is there any in-universe reason given for the heavy concentration of high-level mutant-emergence among populations of European-descent and/or around the geographic area of the United States alone?

Last I read, mutants were caused by genetic manipulations of Earth's primitive populations by the Celestials, million years ago.

Considering that according to current calculation, the time to most recent common ancestors for all humans alive today is just around 2000-4000 years ago, and that Homo sapiens (of which Homo sapiens superior is only a sub-species) only appeared on the planet 0.5 million years ago, any characteristics introduced into the population over a million years ago would be evenly distributed over the entire population; including the potential for omega level and other-less-than-omega-but-more-powerful-than-most-'normal'-mutants mutations (aka the X-Men)

That means population wise, if there are X mutants or just X mutants with X-Men level powers in the US alone, there should be about 20X mutants (of that power-level) over the rest of the world - about 4X in India and China each alone, plus all the rest of Asia, Africa, Europe, the rest of the Americas (Australia should have only around X/10 though, so the around 3-ish in canon is mostly not too far from the expected!)

But they clearly weren't there, even pre-M-Day.

So, my question is: Is there any in-universe reason given for the heavy concentration of high-level mutant-emergence among populations of European-descent and/or around the geographic area of the United States alone?