Talk:Fumikage Tokoyami/@comment-25296247-20160621182439/@comment-213.140.85.101-20160621190257

Untill it is explained exactly how quirks came to be we won't know. Many quircks don't really make sense, since many of them are impossible to inherit through our understanding of evolution, like an engine in your legs or audio jacks hanging from your ears. Some kind of fictional fusion of elements and human genes must have occured. I don't know if you are a manga reader but you will find out a bit about how quirks evolve from generation to generation and that certain quirks are special.

It is not stated, but according to my calculation using the OFA as basis at least a couple of centuries must have passed since the "luminescent baby" incident, so a lot of "crossbreeding" could have happened. If you look at other type of quirks like "animal voice", "acid" and others, their users all have a mutant form deviating from the normal human appearance. This is just the logic of the series, but I'm sure it will get explained at one point in the future