My Dad’s Norwegian great great grandfather, Lars Monsen, was originally from the Bergen area we had been told. He left his ship to marry a girl from Farsund and then settled in Kristiansand. My cousin Dick and I tried to find records about him, but this name was quite common in Hordaland (think Tom Smith). There were 10 candidates for our Lars in the Bergen area, so I used Y DNA testing to figure out which one he was. This is discussed in several previous blog posts (click here and here)
Kristiansand Boat Basin 2015
Sigmund, a friend in Norway, found a paternal line descendant of Ole Monsen Åstveit, my suspected 5rh grandfather. Then Sigmund sent him a Y 37 marker test from Family Tree DNA. This cousin, Einar, and my father subsequently matched at 3 steps, meaning there were three STR markers that were different. Since the common ancestors lived in the 1700s this seemed reasonable, especially after I looked at each of the markers and found them to be faster mutators (click here for that article). On the other hand, my second cousin, also in the R1b haplogroup, matches a 5th cousin of his, descended from an ancestor in the 1600s, at zero steps. Basically any match in the 0-3 range is usually recent enough for the genealogies to line up.
For Christmas this past year, I gave myself the gift of upgrading Einar’s Y STR test to the BigY700 at Family Tree DNA. I had long since upgraded my Dad and that upgrade included more STR markers. For more about the different Y tests try my article Why Y? (irresistible title!) which has links to more resources as well. This upgrade also took Einar’s STR test from 37 markers to 111. Imagine my surprise when I found that at 111 markers they still had only a 3 step difference!
However the purpose of the BigY700 is to look at SNPs rather than the STRs. The SNPs will tell you more about your deeper paternal line ancestry. It is also a good way to confirm a STR match. Another reason to do the big Y is that when you have an active project administrator, you will be able to see the bigger patterns and branches of your section of the Y tree. There are projects for specific surnames as well as for regions and haplogroups and subsets of haplogroups. You can join projects at Family Tree DNA from your dashboard by clicking Group Projects then Join a Project, as shown below.
Many people who see that their ethnicity estimate from a DNA test is way off, think that they cannot trust the other findings from that testing company. That is a false assumption.
When you are shown people who share DNA with you, aka DNA matches, they really are your relatives, although some can be quite distant. What the relationship actually is may not be predicted very accurately, as many relationships share similar amounts of DNA. Examples of that are a grandparent and an aunt or a 2nd cousin and a first cousin once removed. Thus you are usually shown a range of possible relationships. Figuring it out from shared matches and trees can be lots of fun!
Recently “Gail,” a DNA match to my South African 3rd cousin Sharon, contacted me. The only common ethnicity that was shown for them at their testing company was Ashkenazi Jewish. Thus she was assuming that their common ancestors were Jewish.
However the problem is that Gail inherited her 2.7% Jewish from her mother who does not match Sharon. Gail has no Jewish on her father’s side that she knows of. My cousin’s 28% Jewish is from her maternal grandmother. That is the line where Sharon matches me (click here for that story). Gail does not match any other of my many many tested family members on that line.
One of the issues that people of Northern European descent have is that our ancestors intermingled quite a bit. This means that your Scandinavian could be my English and I suspect that is the case here. Another problem is that unlike relative matching, predicting your biological ancestry from your DNA is far from an accurate science (click here for my most recent article of many on that subject)
More accurate than ethnicity are the shared relatives. When looking at the matches Sharon and Gail share, I found a set of common ancestors among them that are from a non Jewish South African line.
Did you know that Ancestry can figure out how you are related to a DNA match if you both have trees linked to your DNA tests? You do not have to have anyone further back than your parents if other relatives have more extensive trees on Ancestry that include your family,
So how do you link your tree to your DNA? First log into Ancestry.com. Then click on DNA Result Summary in the pull down menu under DNA. Next click the gear on the far right that says Settings next to it as shown in the image below.
Once you are on the Settings page, scroll down to the words DNA and family tree linking. Then click that box to get to the page where you can link your test to your tree.
There you will see something like the below image where you can specify the tree and the person to link the DNA test to. When you start typing a name, Ancestry will use auto complete to show possible names from your tree. Once you have selected yourself or the person whose kit it is, click the blue button to make the connection.
The tool Ancestry uses to find and display relationships based on trees linked to DNA results is called ThruLines which I have numerous posts about. Now for an example of what this can produce.
Segment sizes matter for predicting the closeness of a relationship. That is because inherited DNA chunks get divided up with each generation’s recombination, becoming smaller over time. It has often puzzled me that none of the DNA relationship calculators take that into account. The total centimorgans (cM) can be similar for lots of different relationships. Click here for my post on telling half siblings apart from aunt/uncle/niece/nephew relationships by using segment sizes.
Click here for Ancestry’s explanation of how they predict relationships and here for the article at 23andme. Neither mentions segment sizes.
Click this image for my slides demonstrating the DNA painter relationship calculator
My favorite calculator has long been the one at DNA Painter where the table is based on Blaine Bettinger’s collected data and the probabilities are by Leah Larkin based on the Ancestry white paper. It can work from a percentage or a cM value and lights up just the possible relationships in its table. Clicking on any table entry gets a histogram of frequencies. I have slides showing how nicely it works, done for a recent talk about 3rd party DNA tools for the SCGS jamboree. Click the image above to see those. That video should be available to attendees from the web site genealogyjamboree.com
Recently a calculator was published at DNA-SCI which includes segment sizes by asking for the number of segments. I have used it for a number of closer relationships and have been very impressed with its results.
Eight of the ten fully Jewish kits I have access to showed related parents in the “Are Your Parents Related” (AYPR) tool on GEDmatch. I am wondering if this level of relatedness (about a 4th cousin) is generally true among Ashkenazim and other endogamous populations. Or perhaps the GEDmatch parameters need some tweaking?
Sample related segment from a Jewish kit in AYPR
Also a number of married jewish couples I know have discovered that they share a DNA segment. Personally I share 11 cM on the X with my late husband even though I have only one Jewish grandparent. Most testing companies show me as about 30% Jewish.
I can understand that when people live in the same general area for generations, one could easily marry 3rd and 4th cousins. I also know that in the past, cousin marriages were not uncommon among Jews.
I invite all tested fully Jewish people to run that free tool at GEDmatch and then fill out my form on the next page. Please fill it out even when they are not showing as related to help with my statistics.