Boku no Hero Academia

[Buffalobiian]

If we're after a plausible explanation, quirks have been talked about as a form of human evolution. The trend continues when we're talking about having people develop their quirks and getting stronger etc.

From there, I'm going to say that those with quirks, along with those who have acquired quirks, are capable of training to improving their baseline and quirk abilities because they're capable of furthering "evolution".

Don't try to explain it on a genetic/molecular level.

[neflight86]

If we're after a plausible explanation, quirks have been talked about as a form of human evolution. The trend continues when we're talking about having people develop their quirks and getting stronger etc.

From there, I'm going to say that those with quirks, along with those who have acquired quirks, are capable of training to improving their baseline and quirk abilities because they're capable of furthering "evolution".

That's more or less my thinking. It is plausible/consistent enough to me, and my brain can fudge the rest of the details for sake of being entertained.