DNA, Brown Line
By Don Taylor
I was recently asked what I thought about Ancestry’s new ThruLinestm feature, how much did I use it and what do I accept from it. In using autosomal DNA results, it is always good to have a very wide tree. The wider your tree is, the more cousins you have identified, the more likely you will be able to determine the relationship between you and a DNA match.
So, I decided to look at the matches that reach my great-grandparents, Arthur and Mary (Manning) Brown. They had 12 children, 11 of whom reached adulthood, so I figured there would be many cousins there.
I tend to analyze each person left to right, so I started with a 2nd cousin, descended from Victoria Brown.
- Look at the centimorgan (cM) match amount. In this first case, the individual and I share 134 cM across nine segments. Our trees suggest we are 2nd The Shared cM Project 3.0 tool v4 at DNAPainter.com https://dnapainter.com/tools/sharedcmv4 indicates that 2nd cousins should share between 46 and 515 cm of genetic material. So, our match is within the expected range.
- Does the other person’s tree match yours? In this case, we have all of the same data for her grandmother. In order to accept a ThruLinestm display, both 1 and 2 must pass.
- Do the other descendant entries make sense? In this case, the cousin’s father is still living (and thus redacted). I had the same person with no discrepancies in data. Therefore, I am sure of the match. I did contact the individual to learn of her first name and then entered her into my tree in the right place.
The next cousin to analyze is a descendant of Edward Lewis Brown. This cousin and I share 144 cM over seven segments, well within the expected range for 2nd cousins, once removed.
According to ThruLines, this match a great-granddaughter of Edward through her mother and her grandmother both of which have private entries. My records indicate that Edward had ten children, seven of whom were girls. I also don’t have information on any of the granddaughters of Edward. As such, I can’t place this individual on the tree at all. I then contacted the cousin and asked her about her connection to Edward Brown. Her mother and her grandmother’s name if possible. Once I receive that information, if her grandmother matches one of my known children of Edward Brown, I will accept her and her mother’s names from her tree.
Cousin number 3 was somewhat expected. The amount of DNA, 98 cM, fit expectations for 2nd cousins once removed. I had identical information for her grandfather and her great grandfather. Looking at my data, I had four potential women (all living) who could be the mother of this cousin. I contacted her and asked which of the sisters was her mother. She replied, and I placed her onto my tree.
I followed a similar process for all of the other cousins that ThruLinestm provided connections to.
As you can see, my process it to:
- Confirm the shared DNA amount matches expectations for the relationship.
- Confirm the cousin’s descendants from the common ancestor and a known child of the common ancestor.
- Analyze the remaining path to the cousin, assuring things make sense.
Then, I accept the individual’s tree as “tentative” from the grandchild of the common ancestor to the cousin.
I like ThruLinestm, but only for widening my tree to include individuals that are descendants of a known family unit.
Note: I do not even consider anything in the individual’s tree before our common ancestor.