I recently had a message from Kim at AncestryDNA. Kim wrote:
Hello… I am trying to figure out how we are related because you don’t match any of my closest relatives well there’s not that many that have tested anyway. My relatives are from England Scotland Ireland and Sicily.
Kim matched my sister Sharon at AncestryDNA. I wrote back saying that she didn’t match my mom. My guess was that Kim matched my Clarke side. My father’s maternal grandmother was a Clarke. They lived in County Sligo, Ireland but I don’t know much about that family. Before Ireland they may have lived in England or Scotland. I said that I would know more if Kim uploaded to Gedmatch. Kim wrote back to say that her DNA results were already at Gedmatch. Kim’s tree is private as she doesn’t want people copying any mistakes. She also wrote:
I’m pretty new at the DNA stuff and it’s so confusing how some people can match more with other people in the same family.
Kim at Gedmatch
I had told Kim I would know more based on Gedmatch. That is because my family’s DNA is mapped out by chromosome to each of our grandparents. Here is Chromosome 5 for me and two of my sisters:
Below is Kim’s match with my sister Sharon. Kim matches on our paternal side. That is the bottom red bar. The lighter red is from my grandmother. Both her parents were born in Ireland (Frazer and Clarke). Here is the detailed information of how Kim and Sharon match at Gedmatch.com:
This means that Sharon and Kim match on Chromosome 5 between about position 11 and 35 million. At Sharon’s red bar, her lighter red goes to darker red right where she stops matching Kim. That is because Kim and Sharon match on Sharon’s paternal grandmother’s side. Sharon got her DNA from her paternal grandmother up until position 35 million. After that point, the DNA that she got was from her paternal grandfather. If you look at my red bar at the top, I got almost all my Chromosome 5 paternal DNA from my dad’s dad. This is the dark red side where Kim and our family don’t match. That explains why Sharon matches Kim up to 35M and I don’t.
Why Doesn’t Kim Match Heidi at AncestryDNA?
It appears from the map above that Kim should match Heidi more than Sharon as Heidi has more light red on her paternal side. Here is how Heidi and Kim match at Gedmatch:
These matches are pretty close. Note however, that Kim and Heidi match up to 36M. This is just a little way past Kim and Sharon’s match at 35. That is the point where Sharon’s Frazer DNA stopped and her Hartley DNA started on Chromosome 5. My guess is that Gedmatch’s information is more precise than AncestryDNA’s. Even Kim’s ‘One to Many’ list Sharon match shows as being closer than Heidi’s. It is only when the One to One analysis is done, that we see that Heidi is a closer match.
Here is Kim’s ‘One to Many’ List at Gedmatch:
Sharon is at the top of this portion of Kim’s match list. My brother James is next, but I tested him at FTDNA. That means he would not show as a match at AncestryDNA. Heidi is at the bottom of the portion of the list that I copied.
Where Do Kim and Sharon Match Genealogically?
Here is my grandmother’s tree at Ancestry:
Based on Gedmatch, Kim and Sharon could be 3rd cousins, once removed. Let’s round that up to 4th cousins. If they are in the same generation from a common ancestor and they are 4th cousins, then they would have a common ancestor in the column starting with James Frazer above. Note that I have two Spratt ancestors missing. That means that one of my missing ancestors is a Spratt and the wife’s surname is unknown. If the common ancestor is further out, the news gets worse. I have only 6 ancestors at that level out of a potential 16.
As I mentioned, I have not seen Kim’s tree. It is private. However, if we were to look for a common ancestor, a good place to look would be in the area of the last two rows above. The people I have identified lived in Ireland. So that would be a good starting place to look for a common ancestor.
One Last Gedmatch Trick
Gedmatch has a useful utility with a clumsy name: “People who match one or both of 2 kits”. I want to find other people that match both Kim and Heidi. I picked Heidi as she matched Kim slightly higher than Sharon at Gedmatch. Here are some people that match Kim and Heidi on Chromosome 5:
The reference point is Heidi. Heidi’s match with Kim is #2. A yellow match is higher than a green match. #1 above is Catherine. I recognize her at AncestryDNA. In my Ancestry notes for Catherine at Ancestry, I have that Catherine is Heidi and Sharon’s largest match with an unknown connection. Here is one of Catherine’s Sligo ancestors. Sligo is where the Clarke’s lived:
Summary and Conclusions
- I explained by Chromosome mapping how one sibling could match someone and another one would not.
- I confirmed a guess that Kim matched my sisters on their paternal grandmother’s side. This grandmother’s parents were both from Ireland. Searching in Ireland for a common ancestor between Kim and my family would be a good start.
- I made a guess as to why Ancestry showed Kim matching Sharon and not Heidi.
- I found another person who was on Ancestry and Gedmatch. Catherine has a Tighe ancestor in Sligo. This person lived not too far from where my grandmother’s Clarke mother came from. Perhaps my grandmother’s grandmother Jane Spratt was related to the Tighes.