The 23andme Family Tree built from DNA

The dream of every genetic genealogist is to be able to build a family tree from just DNA. 23andme made a terrific start on this with their Beta family tree released in October. Now it is out of test mode and they have added good editing facilities. Being slightly obsessive, I tried it out with almost everyone whose login I have (my family and many friends and clients).

My paternal side tree built with DNA at 23andme is accurate (fixed one cousin)

I find it useful to fill in the names of my ancestors and the child from which my cousins are descended. On my own tree I was able to remove an incorrect generation turning a 3rd cousin into a 2nd cousin. I also like the compact display with nodes for each ancestor and the ancestors of tested relatives. Click here for an excellent and detailed help document at 23andme.

Major missing features are 1) no ability to export the tree and 2) no capability to share it with family members. Those are big drawbacks for serious genealogists like me. The other problem is that I cannot figure out how to get it to recalculate a tree although the documentation refers to that a number of times.

The family tree that 23andme builds from your DNA relatives only includes those who have opted into open sharing or those with whom you have “connected” via that button on their match page. According to the documentation there is a limit as to how many people you can have in a diagram plus the initial trees are built from your closest 20 matches. You can add people to the tree and there seems to be a provision for new relatives going into a side box and getting added from there. I did not see any cases of that.

My Norwegian Dad’s tree is completely accurate. The right side has just relatives on his mother’s tree and left his father’s. I have figured out or been in touch with all his listed matches. The only one I cannot vouch for is a woman who, based on her other family matches, has a different great grandfather from the one on record (it seems to have really been one of my grandfather’s brothers, a widower preacher in that neck of the great plains). No, I have not pursued this after no response from her to several delicately phrased emails a few years ago.

The only inconsistency is that there are several matches from Dad’s Halling great grandparents that do not show on his tree but show on mine.

My Jewish husband Steve’s tree was most interesting as it showed all his DNA relatives as being from one side which was incorrect. Possibly because Jewish people from the same geographic area, Galicia in his case, will always have some shared DNA from past cousin marriages. The key with Jewish matches is to look at segment sizes.

It may well be that most of my husband’s matches are actually from his mother’s side since many of them emigrated to America early in the 20th century. While his father had only one full sibling who came here and we know almost nothing about his father’s grandparents and whether there were any other relatives who survived the Holocaust. The one DNA relative known to be on his father’s side I was able to move over there with the editing tools.

My husband’s maternal side showed his grandmother’s sister Blima in the wrong generation

Another issue is that my husband was born when his mother was in her 40s so his age does not correspond well to his generation. Perhaps that is why the sister of his grandmother was shown one generation further back. That was easily fixed by using the “move a branch” feature.

My German born half Jewish aunt has no people in her tree on her maternal Bavarian side which is not a surprise since none of them are tested at 23andme. There are eleven people that are listed as descended from her great great grandparents who are very unlikely. I will have to go through them all. Apparently 23andme does not realize that you must share large segments to be that close a match when you are from an endogamous group. My current rule of thumb is one segment > 20 cM and another > 10 cM among several segments. So for example our newly found South African cousin, a real 2nd once removed to my aunt, shares segments that are 44 cM, 22 cM, and 3 more smaller ones. She is Sharon on the far right of the chart.

In my Aunts tree there are many false matches, only the close ones and far right ones are good

One of those unlikely ones is Leslie who shares a total 83 cM over 9 segments with the largest being 11cM and most are between 6-8cM (I excluded the X from these comparisons) so likely is related more than once and distantly. Those Langermann ancestors were from a very small town where everyone was often related to their spouse. A fellow researcher was fond of telling me that all of us Southern German Jews are related; sure enough he shares a 7 cM segment with me and my aunt!

My newly found 3rd cousin’s tree could not manage the half relationship with her half first cousins and added a generation into her tree making them 2nd cousins. Not surprising. My aunt made it into her tree but I didn’t.

An unknown father case which has long since been resolved showed nothing on his paternal side. His closest 23andme paternal matches are 2nd to 3rd cousins with whom he never “connected” and presumably they are not doing open sharing. One would think this tree feature would be useful for adoptees but so far it has not been for me, but then I get consulted on the tough cases.

Most of the trees of the non-endogamous that I looked at were very accurate except for half and double relationships.

In conclusion, this is not yet a terribly useful tool but it is fun and interesting and I look forward to it’s future improvements.

UPDATE  1- June-2020: I recalculated my brother’s tree by clicking on Info & FAQs on the top right of the tree page, then scrolling down the next FAQ page to the “I edited relationships, but I want to undo them…” (see image below). There I clicked the red button to delete my edits and recalculate. I was willing to lose the edits on his tree but not on mine. Nothing was truly lost, but all the names I had added were now in the box on the left so I had to reassign them to the correct nodes in the tree.

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15 thoughts on “The 23andme Family Tree built from DNA

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  1. A cousin tested recently so I got the ‘add’ box for her. Only, she is already on my tree. Her son had already tested and I had filled her in. She does show a DNA mark on her name. But I am told I need to reset to get rid of the box – which it adds, would get rid of the edits I made, the people I added…

    • Ellen I think you can just.click on the node where listed her and then edit and clear all her information. Then you should be able to move her from the box to her place on the tree

  2. I started playing with the 23andMe Family Tree feature when it first became available. Initially, it was wildly inaccurate, with cousins on my mother’s side shown on my father’s as a obvious (to me) error. When they allowed editing, I fixed what I could, but initially they didn’t support moving someone from one location to another. After they added that, I made further corrections and additions.

    The references I’ve seen to recalculating the tree suggest that to do so, you have to let the system delete ALL of your edits. Perhaps I saw more issues having started as an early adopter, but I’m not willing to throw away the effort I’ve put in with the hopes that maybe they’ll do a better job of predicting relationships for matches. Besides, they can’t know anything about names of other people, like my late parents, grandparents, great-grandparents, etc., and throwing all of that away just don’t seem worthwhile.

    • William, I tried the delete all on my brother’s tree and it did not delete the added names, they just went into the box and were easy to readd. See my update above.

  3. Thanks, Kitty! I did have things to do today, but I’ve spent most of it playing with this! Other than a couple of 2C 1xR that they called 2C 2xR, I didn’t find any errors.

    • Nancy,
      thanks you make me feel better, believe it or not I had been working on this post on and off for over a week, playing with the tree endlessly in multiple accounts. And I just updated the post (see the end)!
      Yes, I have things to do today too!

  4. When I initially turned the Beta DNA Family Tree on it was surprisingly accurate for both my test and my sisters with just a slight difference — my test had Mom’s side on the left and Dad’s on the right while my sister’s had it the traditional way Dad left, Mom right. But a few months ago a new match came in that was related to both Dad and Mom and blew both trees up. Now almost everything on my tree is on one side and there’s an extra confused generation between parent and grandparent level. There is one branch on the opposite side but again an extra generation stuck in and at the time no way to fix it. On my sister’s tree everything is on Mom’s side though I can see this grouping should be Dad’s and this group should be Mom’s but no way to add names with it so messed up.

    So Mom got another DNA test for this Mother’s Day. This morning her test was at the review stage and this evening its computing results. If we are lucky we will have results tomorrow or the next day and hopefully a prettier, more accurate tree again.

    But I don’t hold out too much hope. I need some 1/2 cousin designations to better define some relationships. And it will be interesting if my double second cousins finally fall in the correct place as of right now their grandma/grandpa and my grandma/grandpa are showing as the same couple rather than two brothers marrying two sisters making us double cousins.

    My first experience with this tool impressed me but when the wacky happened I became unimpressed. Will tomorrow change that view again?

    I’m waiting for Mom’s results to see what happens before I explore the editing tools.

  5. I have been plying with the tree since it was in beta and applaud 23andme for trying this and for the improvements made before releasing it from beta. My tree was a big mess. I’ve recalculated a few times, but even with notes and the names saved in the unplaced box, it takes quite a bit of time to rebuild,

    What I would like to have is the ability to remove DNA matches they place that I do not know where they belong in my tree, I’d like to have them in the unplaced box. I would also like to be able to add matches I know and have the DNA match symbol attach to them,
    I’m looking forward to further updates since this could benefit many people.

  6. I have re-calculated my tree but it is annoying to replace everyone. I too find not being able to add known connections a significant issue. My other major criticism is the inability to add enough ancestral levels to correct mis-aligned branches.
    However, I do like this as a good first try!

    • I agree with you, adding another generation to make things work would be nice. Maybe because French Canadians have a lot of common ancestors, we test genetically closer than we are on the family tree. My other problem is that I have people related to me both maternally and paternally and this doesn’t seem to allow my dad’s cousin to be the same person as my mom’s aunt by marriage. It’s a pretty frustrating and inflexible tool.

  7. I’d like to see more generations enabled. With the current limit of 7, if there are grandchildren of the primary account holder then only 4 ancestral generations are available.

  8. It appears that you and other people have had some success with their 23andMe tree. I am pleased for you, but for me it is a disappointment.
    The tree shows me and only one of my matches. It shows a connection from one of my four grandparents to a sibling of the match’s 2nd great grandparents. The match does not have a tree. Without some other information, it is going to be very hard to figure this out. For a start, I have no idea which of my four grandparents might be a connection, and presumably the connection shown, is probably just a guess based on the amount of shared DNA. The odds are just too great to do anything with this.

    • well Vernon, I have spent years figuring out how my family’s DNA works and twisted many cousins’ arms to test. Thus when I get a new connection, I can look to see who they are in common with and on 23andme to figure it out. Plus I can look at actual segments and often know which ancestor a segment is from.

      • I understand your strategy, and it is something that I have done too with other testing companies. I have bought tests for cousins on Ancestry and uploaded their data to FTDNA and MyHeritage, but have not done this on 23andMe. Partly this was because they are much more expensive, and partly because I have had no success figuring out any of my matches on 23andMe. They have not made it easy for genealogists. Without any trees to guide you, it is hard to make any headway. I can see who is in common with a match but if those people also do not have trees, how is that useful? I guess that you are just going to tell me to try harder.

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