Can you guess my ethnicity/origin/Y-DNA?

[Kisuan]

Not bad looking at all.
I'm an amateur at anthropological classifications, but I guess...."Eastern Mediterranean"? Seriously, I don't have extremely great insights on the subject matter. :/

 

[RobertColumbia]

...People are remarkably good at isolating themselves reproductively, especially when religion is involved. We've been talking about it in regard to a new paper that discusses assortative mating.

Look at all those German villages scattered throughout southeastern and eastern Europe. Even when they shared a religion they remained distinct from the surrounding population for hundreds of years....

Great point. For a current example, look at Amish communities in the USA. They prefer to marry only among themselves and they receive very few converts. This has actually made them notably less diverse in a genetic sense from surrounding (non-Amish) German-Americans and who have become significantly admixed with Irish and other groups. Hasidic Jews, the other "funny hat" religious group of the US East Coast, is showing signs of heading in the same direction. Neither group bans converts, but converting just isn't common (or easy from a social perspective).