You might hear some people say that the twelve tribes of the house of Israel have been done away with and are now mixed up with the other nations, in a way that cannot be recovered from. Yet when you go to any country and find a Chinese community, they still look Chinese. If you then go and find an Indian community, they still look Indian, with hardly any of them looking mixed. I remember a woman saying a similar thing about the slave class people in America, saying that a lot of them have married outside their race and have ended up with mixed race children, but I said to her that when I saw a picture of a prison chain gang, the inmates all had proper dark skin, without any sign of mixing. To me this shows that they are still around somewhere, but you won't really find the majority of them rolling with the posh people, so they won't be as visible as the other nations are. If you are ready to dig a bit deeper into this matter, then get in touch for a study on this subject.