I find it interesting that many people in this thread are already so certain of their ancestry, from their research.
Of course, some trees are better researched than others (we've all seen the threads on "ancestry" trees...

However, even the best, "gold standard" research, even with 3 (or even more) pieces of primary
documentation for each fact, is only,
can only be, based on what was written down at the time.
DNA testing offers at least the possibility of a truly primary source.
The case of Thomas Jefferson and Sally Hemings wouldn't ever have been resolved historical documents.
BugBear