if a white person has dominantly white genes what are they?John Punch (slave) - Wikipedia
en.m.wikipedia.org
I never said having admixture made a person biracial. I was working off your definition of Black being, "anyone with historical and dominate ancestry (post human migration) from the continent of africa."
Given that definition, if a person's DNA is a majority African (dominant ancestry), they would be classified as Black.
If Zazie's kids who are mostly white marry a Black person, their kids would be Black, not biracial based on your definition alone. The majority of their DNA would be African.
Same logic would apply in my post you quoted.
then if they breed with someone who is classified as black (despite admixture) what are they? black no?
what would their kids be? we have so far agreed, white and black with the above examples.