Can a blood test determine ethnicity?

Question

Can a blood test determine ethnicity?

Answer 1

Not necessarily.

There are DNA test.  Your blood, your saliva, your skin, your bones contain DNA.

To do a DNA test they won't use blood.  The companies that do them will send you a kit. You usually swab the inside of your cheek with a q tip type device and send it back to them.

However, it will not give you specific nationality, racial or ethnicity.  It will, for instance indicate Northern European, West African, East Asian but nothing more specific.

Y DNA is passed from father to son only.

Mitochondrial DNA is passed from mother to both sons and daughters but only the daughters pass it on to their children.

Y & Mitochondrial are used in genealogy to match a person up with someone else's family tree.  However, most of your DNA is autosomal.  You get it 50-50 from both parents.  It is the only DNA that relates a female to her father or anyone to the spouses of the direct male and direct female line ancestors and their families.

For instance if you go back to your 6xgreat grandparents, you are directly descended from 510 people.  You get mitochondrial DNA from only 8 of those people and if you are a male you get Y dna from only 8 of those people.  However, you get autosomal DNA from all 510.   For someone to get ethnic percentages in their DNA the testing company would have to use autosomal.

Answer 2

Supposedly but thats whether you believe it to be exact.