DNA Detection

[darkerhorse]

This isn't about Italian ancestry, but I thought it fit better here than in the Other category. I'm sure M-uzzu will find it.

According to my paper trail, I'm 1/16 German, 1/16 Danish, and 2/16 Norwegian from my maternal grandfather's line (summing to 25%).

The 1/16 German is a 2x great-grandmother born in Norway of immigrant German parents.

Based on one of the surnames, I highly suspect some of the Danish also comes from Germany, sometime before my 3x great-grandfather who was born in Denmark.

That means I could be as much as 2/16 German, if the 1/16 Danish is ultimately German.

How likely is a DNA test expected to capture German ancestry, given it's only 6.25% by paper trail, introduced four generations back?

My next question is what percent German would you expect in my DNA if the Danish was also German?

[darkerhorse]

The math was wrong.

By paper trail is 1/32 German (3x great-grandfather), 2/32 Danish (two 3x great-grandparents), and 5/32 Norwegian (5 3x great-grandparents).

That means 3.125% German, 3.125% Danish, and 18.75% Norwegian by paper trail.

Even less detectable German.

Also, I suspect only half of the Danish might be German, not all of it.

So there.

[MarcuccioV]

Depends on what matrix you test with (or upload to). Ancestry, for example, might give you a certain "best guess" percentage and then show a fairly wide range as to what it "could" be -- and I'm sure the other matrices are very similar. Bare in mind the further back you go, the more likely for any one ethnicity (even if the same ethnicity is from a different source) can get "filtered out" due to random recombination. So your answer is probably going to be around 1-3%. I doubt you can get any more precise than that...

[darkerhorse]

I suppose another strategy is to look at the ancestry of DNA matches.

[darkerhorse]

Say, DNA testing results in 6% German.

Would it more likely be by chance (I inherited more than the expected fair share of German (3%) from the one German ancestor) or because what the paper trail reports as Danish is really originally German, as I suspect because of the surname?

In this example, I'm ignoring the fact that German and Danish may be difficult to differentiate from each other.

[MarcuccioV]

Another wrench to throw into the works is often regions overlap each other -- in Ancestry's case, England and NW Europe are combined; this includes Holland, Belgium & Denmark, while Germany is separate as well as Norway and Sweden. Yet the borders are not precise. And Wales and Scotland are also separated out. It really makes no sense, but that's how they do it. Others simply place generic geographic regions that can overlap considerably. Throw in people that migrated throughout northern Europe & you have a real mess. I have the same issues on my paternal side -- there doesn't seem to be any distinct delineation to make any kind of reasonable conclusion. Trust me, it's beyond frustrating...