Archives

23andMe Update

Sep25

23andMe is now owned by​ Anne Wojcicki’s new non-profit The 23andMe Research Institute. An email has gone out to all of us users (see next page) explaining this, which also makes it clear that the focus will be on discovering the health issues in our DNA. Click here for my previous post on 23andme explaining why ​Anne has this interest. 

While crowd sourcing DNA health issues is certainly a worthy cause, it is not the main interest for many of us. Most of my readers consider genetic genealogy a tool to find relatives and uncover family stories.

How the former chromosome browser at 23andme looked comparing a new match to me and my family

The feature I miss the most at 23andme is the chromosome browser that showed ​where my genome matched that of my relatives. Because I have collected an excel file of all my father’s matches with notations as to which I or my brother share, I could frequently tell which family line a new match belonged to,  even a one segment match with no clear relatives in common. ​ Click here for the blog post where I discuss this.

I no longer recommend testing at 23andme unless you want health results or are an adoptee and thus need to test everywhere.

The next page has the text of the email they have sent all of us users.

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Half Sister or Aunt?

Sep18

There are many stories about families where the baby of an unwed teen was passed off as her own mother’s child. A recent query in a FaceBook group asked whether DNA testing could tell whether her aunt, her mother’s much younger presumed sister, was one of those cases, so actually the asker’s half sister. The problem is that the amount of cM shared by those two relationships completely overlaps, roughly 1600-2000 with outliers (click here for the charts at DNApainter).

Known paternal half siblings at DNA-sci

Previously I collected data and studied segment sizes to see how to tell those relationships apart (click here), finding that paternal half siblings will share more larger segments than aunt/uncles. However in this particular case, maternal half siblings, the difference is less clear. Click here for the calculator at DNA-SCI that takes segment sizes into account by using the number of segments. When I tried using it with the numbers of a pair of known paternal half siblings, that calculator predicted that aunt or uncle was more likely (see image). So this approach will not give a clear answer.

A half sister will get half their DNA from their other parent. This will usually result in some close matches that are not shared.  On the other hand, an aunt’s close matches should all be shared with her niece, since they share the same ancestors, so looking at their “not in common” matches might work. The niece, however, is expected to have close matches from her other parent’s side. Here are some half sibling examples from the tool “Match Both or 1 of 2” on GEDmatch:

The kits that match only half sibling A0 and not A5

The kits that match only half sibling A5 and not A0

Notice that each half sibling has a match larger than 200 cM that is not shared with the other. If you have pro tools and access to both accounts on Ancestry, you can also look at this by comparing each person’s list and the matches in common. There is no automated way to do that there yet. Family Tree DNA has a “not in common with” feature, but no other company has it.

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The new clustering tool at Ancestry

Jul6

Ancestry has been rolling out its clustering feature this past week to those of us with a Pro Tools subscription. If you have it, there is a new button at the top of your list of matches with an icon that says “By Cluster.”

The purpose of clustering is to create an easy-to-use visual way of organizing DNA matches that are related to you and to each other. The graphic sorts the matches who share 65 cM to 1,300 cM with you into groups who also share at least 20 cM with each other. Each match is listed in the rows on the left as well as by initials at the top for each column. In a perfect world, you would get four colored boxes, like in the image below, where each box represents the line of one of your grandparents.

The image above has actually had the top box truncated and two additional boxes removed for illustration purposes. The left side would have the full name of the match while the top has just the initials.

Some matches will also have additional matching that does not fit the groupings. Those are shown in gray.The darker boxes on the diagonal are where the same person meets themself. Note that all the boxes, even the ones that are not colored, are clickable to show who the two people that intersect there are, with all the details of that match. Plus the names can be clicked to go to those match pages. Clicking a square brings up a box like in this image.


Below the diagram there is  a list of the clusters. Click on any one to see the members of that group. Notice that each member has all the information you would see about that person in your match list. Another nice feature is that you can add everyone in a cluster to a colored dot group by clicking on the “+ Add All” button.


While this sounds like a wonderful new tool, for many of us it needs the ability to specify the range to include in order to get the best boxes. Below is what a Jewish friend of mine gets; lots of clear small boxes, but everyone is related to everyone else outside of the clusters, except for her middle box. This is what endogamy looks like!

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A Breakthrough in my German DNA

Jun17

Modern day Germans do not seem to do DNA testing. I have one German grandparent born in Munich, with several generations of Bavarian ancestors, whose line I never get any matches to. Since this is my mother’s mother’s line with the paternal lines proven, the lack of matches is not due to an NPE (non parental event). For example, I have one German half 2nd cousin on my maternal grandmother’s father’s side who tested at my request (click here for that post).

Ancestry has a nice new feature where you can filter your matches by Journeys (where your ancestors came from); see image to the left. I was disappointed not to have any German journeys, but my brother has something called Franconia. When I used that filter I found a good match at the top of his list. Richard, from Pennsylvania (think Pennsylvania Dutch aka Deutsch), with an Italian surname, shares 72cM with my brother, 62 cM with me, and 25 cM with our first cousin Margaret. Richard’s tree had no ancestors listed, but his closest shared match to us, a great nephew, did have a small tree. One thing I like to do with my Pro Tools is to change the way matches are sorted to be by the best ones for the match I am looking at, rather than the usual sort of those closest to me (see image below). Their close matches often have better trees or have notes I wrote to myself when I figured them out long ago.

That nephew has all but one person showing as private in his tree. Luckily the one person whose name shows has the same surname as Richard. Next I clicked over to her profile page and used the Ancestry search function to find a more complete tree for her, which included her parents. Her mother Frances had a surname, LANG, that I knew was in my tree. She was even born in the same town, Eslarn, Bavaria, as my great grandmother Margaretha Wittman! Another search at ancestry found Francis’ Eslarn grandparents’ names in yet another tree, whose owner was also a distant DNA match.

There is a useful German website – https://www.ortsfamilienbuecher.de/ – which has genealogy information from many German town lineage books, including the one for Eslarn. You can list everyone with a specific surname in your town to search for an individual. Be sure to check alternate spellings. Armed with the names of Frances Lang’s grandparents, I went to that source and traced her mother back to my great grandmother’s grandparents. This was not easy because the same names were used over and over again. Frances’ mother had the same name as my great grandmother. Also their fathers, who were uncle and nephew, had the same name, Joseph Widmann/Wittman. Complicated to figure this out, but birth years helped.

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Finding the Fallen with DNA

May29

Guest post by Wesley Johnston

On Memorial Day Weekend, GEDmatch announced a hugely important “Fallen Warriors-The Unknowns” initiative (click here for the details ).

Image by Jed Henry, from the documentary “Honoring a Commitment – The PFC Lawrence S. Gordon Story”, video on youtube and embedded below.

Family members of soldiers still missing in action from World War II and Korea can upload their autosomal DNA (aDNA) results to GEDmatch no matter what company did their test. And they can obtain the very important Individual Deceased Personnel File for their soldier. Plus everyone can upload their aDNA to increase the probability of matching with the DNA of an Unknown soldier.

GEDmatch’s initiative will bring the DNA of family members of those still missing into a database with which the DNA of any Unknown remains can be compared, easily, quickly and at minimal cost. In fact, GEDmatch probably already holds the DNA of family members of the Unknowns.

This is a wonderful thing for GEDmatch to do!!

Genetic genealogy readers may know me from my work in genetic genealogy: my analytical tool articles in the Journal of Genetic Genealogy (JoGG), the many Family Tree DNA (FTDNA) projects I administer, the conferences I attend. One of the many other hats I wear is Historian of the US 7th Armored Division Association; another is Founding President of the American WWII Association Historians Consortium.

This is what led to me present “When John Doe is a WWII Unknown Soldier“ at the 2024 East Coast Genetic Genealogy Conference (ECGGC).

In our modern era, when law enforcement and the DNA Doe Project have embraced Investigative Genetic Genealogy (IGG) to solve cases in far shorter time and a far smaller cost, it is difficult to understand that the Defense POW-MIA Accounting Agency (DPAA), whose mission is “fullest possible accounting” relegates DNA to the last step of their years-long identification process of anthropologists examining remains, instead of the first step.

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