How does a DNA test tell you which nationality you are?

Question: How does a DNA test tell you which nationality you are!?

I saw a question on here about a person wanting to have a DNA test to find out which nationality they are, and which tribe they originally come from!. How would that work!?Www@QuestionHome@Com

Best Answer - Chosen by Asker:

With the human genome sequenced, we have available tens of thousands of DNA samples with information on the ethnicity and national background of the people they came from!. It is possible, for some countries and areas, to find patterns that built up when people were settled there for some time!. So if your DNA matches those patterns, more or less, it can suggest your background!. Of course, if your great, great, great grandparents immigrated to South Dakota from Russia and lived among similar immigrants, such a test is going to indicate a Russian nationality!. And if they moved around between generations, then it will be muddled - there is probably no "United States of America" nationality pattern!. But Hungarian, central African, Norwegian, etc!., are possibleWww@QuestionHome@Com

if the blood is red, white, and blue, then you are a yank, lolWww@QuestionHome@Com