Working with AncestryDNA matches.

I have covered this topic before; however, I have found that some people need this explained more than once to fully understand it. It can be a little confusing.

I have been helping my friend, E.B. with her DNA results. She had her mother, L.S. (her only living parent) tested. This is the first time I ever got to work with DNA results that show a parent’s matches with the extra built in label of “Mother’s side”. I had already started to color code E.B. shared matches before her mother’s results came in. We are trying to figure out who E.B.'s father’s biological father is. Therefore it was really nice to see “Mother’s Side” was being matched up with those I sorted as being from her mother’s side. However, I do know I saw a few matches that appeared to fall into both her mother’s side and her father’s side.

Before I go any further, let me cover a little background for those who are newer with DNA and sorting and matching. I have found with AncestryDNA matches, using the Dana Leed’s Method of sorting is quite useful. You can find it explained by her at her website 

How shared matches work. When you go into your DNA Matches (let’s call you A) and you select one of your DNA matches (let’s call them B). You can then review all your shared matches (let’s call them C-Z). These are DNA matches that match both A and B. Normal logic states, that if A and B have a known common ancestor or ancestors (married couple), then shared matches C-Z should match either the known common ancestor(s) or one of their ancestors. Look at the chart below, see you are A and your selected match B have a common set of ancestors. C-Z might share a common ancestor(s) at the same level as A and B or any ancestor further back on those lines. This is how the Leed’s Method works.

Keep in mind, all DNA 2^nd cousins or closer will match each other. Therefore, if you have two unknown DNA 2^nd cousins and they don’t match each other; they come from different lines of your tree. You have four sets of Great Grandparents and these two 2^nd cousins come for two different sets of Great Grandparents.

Also keep in mind, that AncestryDNA use of 1^st cousin, 2^nd cousin, etc.… are just for sorting purposes and is based on your shared centimorgans. There are averages of centimorgans that relatives will share based on their relationship. However, DNA is so random that the further you go out, these could be higher or lower than average. Therefore, you might find a 2^nd Cousin listed under your 3^rd cousin heading in AncestryDNA. This is just a suggestion. Plus, not all your DNA matches will be exactly a 2^nd cousin, 3^rd cousin, etc… Some might be a 2^nd cousin once removed or a 3^rd cousin twice removed. Basically to be exactly a 2^nd cousin or 3^rd cousin as an example, your common ancestor must be the same relationship to both of you. 2^nd cousins share Great Grandparents, while 3^rd cousins share Great Great grandparents. Removed can be confusing, however, think of your first cousin’s kids. These are your 1^st cousin once removed because your grandparents are your first cousin’s kids great grandparents. Your common ancestors do not have the same relationship to you as your first cousin’s kids.

The chart below show a simple Pedigree chart with ahnetafel numbering system, this system starts with the main person, usually you as 1 and your father is twice your number and your mother is twice plus one. This continues in this fashion for as many generations you need to go back. So when I am helping people with their DNA results and when I figure out the most likely common ancestor, I like to use the ahnetafel numbering system so I can see their placement on the pedigree chart easier. The top of the chart shows the relationship of each generation to you and the bottom of the chart shows which generation would be 2^nd cousins versus 3^rd cousins.

Okay, now back to my research problem. My friend as a DNA match (J.S.) showing up in her 2^nd Cousin bucket and is related to her and her mother. However when I bring up J.S.’s shared matches, she has two shared matches that are from my friend, E.B.’s father’s side. These shared matches do not show up for E.B’s mother, L.S..

 

Also, J.S. really isn’t a 2^nd cousin to E.B., in fact, J.S. is the great granddaughter of L.S.’s sister. Therefore, J.S. is the 1^st cousin twice removed of E.B. and the great great niece to L.S. Their common ancestor is E.B’s maternal grandparents (6 & 7). Lucky for me, J.S. matches A.B. and A.B.’s mother C.B. two matches that I already figured who their common ancestor to E.B. Plus A.B. has a very nice developed tree, while J.S., not so much.

When I first looked at J.S.’s tree, I did some quick research on the only names she had on her tree and when I found obituaries for J.S.’s grandparents, this is where I was given J.S.’s parents name.   J.S. used her real name and I found the S surname already in the tree for E.B. since S married L.S.’s sister’s daughter. J.S’s father is the grandson of L.S.’s sister.  Therefore, I was able to place J.S. into E.B.’s tree.

Next I turned to figuring out how J.S. was related to A.B. and C.B. The locations for J.S. maternal grandparents did not match A.B’s tree. So I turned to J.S.'s paternal grandfather (S). I did some quick research and found that S’s father had married a Pauly and her parents were listed in A.B’s tree. Also, Ancestry has common surname between E.B. and A.B. listed in green. Ironically, a Pauly married a Friedel (the surname from E.B.’s tree). Therefore, I might come across more DNA shared matches that show they have maternal and paternal matches to E.B. and this will be the first place to start looking.