Tip 13: More about Ethnicity

Youtube throws odd things at me. Recently as I was trolling for cake recipes, it suggested this video on DNA. https://www.youtube.com/watch?v=9hbE4Vihf4g
He had two charts that I really liked and thought I would share.
We get these odd small bits and wonder where they came from. In some cases, they can be helpful by sorting your matches. Recently I have been working on someone who has a small % of Native American. About half his matches on his father’s side share that and about half don’t. We all have enough experience in this that we would have a tendency to say one is one grandparent and the other is the other grandparent. So I went through and grouped the larger ones by this and a definite pattern emerged. But when I looked at the trees, I realized that a few of those who do NOT have Native American, should have about 1-2 % but they have lost it along the way. So how does this happen?
First of all, this is a chart of how we inherit DNA. You all know this. 50% comes from each parent. Yada yada yada.

If your DNA shows up having 3% of Native American for example, you might go looking for that ancestor at the 5th generation level. Or perhaps around there. However, there are some real provisos with that statement. The above is the expected inheritance. But when they say you inherit 50% from a parent, that is a random 50%. In fact, you get 60-40% from each grandparent. So the farther away you are from the source, the wider the possibilities. So that 3% you are looking for could be at any one of these levels below.

It also explains why certain people who should carry some of that Native American DNA do not. One woman I was looking at had a 5th great grandfather who was a member of the Choctaw nation. Some of his children signed up on the Dawes rolls. But Ancestry says she has zero Native American.
This also explains why some of us who were told that our so-and-so was Cherokee or something like that, but do not actually show up with any DNA. However, if you check on Gedmatch, you will probably have 1-2% Native American and 1-2% Siberian or East Asian which is from the same source.
Also take a look at the year spread. My own Native American should have been back at the 6-generation level according to the family stories. But for me that is over 200 years ago. It just depends. I have never thought much of Ancestry’s ethnicity estimates, as I have said on a number of times. Gedmatch is the best in general.
June Byrne
DNAAdoption.org