[68skylark]

What if you're a mongrel like me? I suspect they coerce the results into the closest match they can find. But that doesn't mean it reflects reality.

I'm no expert here, but you direct paternal line can only come from one ethnic group, right? And your direct maternal line can also come from only one group too, right?

[DGray]

No, your direct lines can go through many ethnic groups, and many Americans' will.

[night reader]

I'm no expert here, but you direct paternal line can only come from one ethnic group, right? And your direct maternal line can also come from only one group too, right?

Right! But if you only go back ten generations, you have 512 ancestors. Direct paternal and direct maternal only takes care of two of them. How about the other 510? And ten generations is not "deep ancestry." In short order you get into the millions of ancestors, more, in fact, than the total population of the earth. Oops! Do I smell an incest scandal here?