I thought they were an ethnic group?  Enlighten me. There is no single Jewish ethnic group. There are actually several different Jewish ethnic groups. The primary ones being the Ashkenazim, Sephardim and Mizrahim, these three groups comprise almost the entirety of the world's Jewish population. And even amongst these ethnic groups, there is still no such thing as a pure Ashkenazi or pure Mizrahi Jew as much as some people would like you to think so. They are mixed breeds, a biological Jew is a mutt and usually inbred too:D