Language is common understanding (within boundaries). Sure, there is subjective understanding, but only to a point. As I understand it, the concept of ancestry

Language is common understanding (within boundaries). Sure, there is subjective understanding, but only to a point. As I understand it, the concept of ancestry in English implies a certain immutability. You can't be Asian today and African tomorrow. You can't identify as Eskimo one day and Pacific Islander the next (barring a rather unusual situation). You can't change identity like clothes. There are words for people who do that, though, "actor" being the kindest. If you want to redefine the meanings of these terms, fine, but then we're no longer using the same words, even if the syllables happen to sound the same. I never said 1227 and don't know why you are picking that year. I picked Genghis Khan because supposedly most everyone has some of his genes.