Use WikiTree to Find DNA Cousins

Diahan Southard

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Use WikiTree to identify potential DNA matches—genetic cousins. This variation on targeted testing can help you explore whether you’re related to a specific ancestor.

In the opening scene of the animated movie Aladdin, a traveling salesman is trying to sell us a “combination hookah and coffee maker.” “It also makes julienne fries!” he claims before breaking it (as he’s trying to demonstrate its durability).

I feel like we are always looking for tools that multi-task the job of turning our DNA cousins into ancestral discoveries. Some of the best tools in this department have been developed by our testing companies. You might hear me call these “cheating tools” (giving them cart blanche in our relationships is dangerous). But still, they are very helpful.

One of the most powerful questions we can ask our DNA is, “Am I related to Ancestor Z?” If that ancestor is your 3X great grandparent or closer, autosomal DNA testing can help us answer that question.

To test our theory, we absolutely have to have other documented descendants of Z. (This is one application of what we call targeted DNA testing.) Having a quick and easy way to find others who have tested who are descendants of Z is critical. So far, the only DNA testing company that makes it relatively easy to see that kind of information is AncestryDNA’s ThruLines. Once you link your own tree to your DNA, you can click on any ancestors (who are included in ThruLines) and see others who have a) had their DNA tested, and b) have ancestor Z in their tree.

Ah, but do you see the potential problem here? What if you DON’T see any DNA matches who descend from Ancestor Z? Does that mean you aren’t related to Z? Or does it just mean that no one else has tested who has this ancestor in their tree? Without more information, it is impossible to tell which is the case.

WikiTree for DNA Matching

Enter WikiTree. Wikitree is a genealogy website that is committed to “grow an accurate single family tree that connects us all and is freely available to us all.” There are lots of great features on WikiTree. Of course, here, we will focus on the DNA features.

First of all, upload your GEDcom (family tree) file. Next, indicate which individuals on your family tree have taken a Y DNA, mtDNA, or autosomal DNA test. Indicate the testing company and username. This helps others find you as a DNA match wherever you’ve tested—just like you’re about to do with them.

The system will then use what it has been told about DNA inheritance, and use that to populate some fun features on the site.

The feature that is most exciting is under My WikiTree > DNA Confirmation. As per the description on the page, the ACA or Ancestor Confirmation Aid “reveals other descendants of your ancestors whose DNA tests could be used to scientifically confirm relationships in your family tree.”

WikiTree DNA Confirmation aid.png

Essentially, this is the multi-tool we need to help us find descendants of our ancestors who can test (if they haven’t already) to help us verify (or refute) our connection to a particular ancestor.

This tool is unique because it will allow us to see everyone on WikiTree who is a descendant of Z, not just those who happen to share DNA with us on one particular testing site (like you see in ThruLines). Importantly, if you see 10 descendants of your presumed 3X great grandparent who have taken a DNA test at the same company where you’ve tested, and you do NOT see them on your match list….Well, let’s just say your connection to that ancestor looks less likely.

It is important to keep two things in mind:

  1. You won’t share DNA with all of your cousins. In fact, you will only share DNA with about half of your 4th cousins. But if a significant number of 4th cousins have tested and you do not match any of them, that should give you pause.
  2. Just because you share DNA with 10 descendants of Ancestor Z, this does not mean that you have to be his descendant. There are always other explanations for shared DNA. The DNA is meant to be a hint to help you see where you can look in the paper research to verify your connection.

This is just one of the many multi-tool functions of Wikitree. It is definitely worth creating a free account and having a look around.

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<a href="" target="_self">Diahan Southard</a>

Diahan Southard

As founder and CEO of Your DNA Guide, Diahan Southard has been teaching people how to find family history answers in their DNA for several years, and she's been in the genetic genealogy field since its infancy. Diahan teaches internationally, writes for popular magazines, consults with leading testing companies, is author of Your DNA Guide–The Book, and producer of Your DNA Guide–the Academy, an online learning experience.


  1. Kathleen Woodbury

    Diahan, I have registered with WikiTree and put myself and my parents there in a rudimentary “tree” there.
    After reading this blog entry of yours, I logged into WikiTree and tried to see how to upload a gedcom file (I have one for each of my parents that I’d like to upload). But I can’t see anything anywhere that tells me how to upload a gedcom file. I would think it should be on the “edit family” page, but I can’t seem to see it anywhere.

  2. Shirley


    So I have an Ancestor Z.

    My family has lived in Eastern Canada for generations -but no one has ever been found to be related to us. So I followed my aunt’s 40 yr + research. She “felt” that a family who arrived from Ireland in the very early 1800s and then “appeared” to leave years later for the US and had a “similar” name but not spelling was the one we were possibly related to.

    I took her notes, followed the paper trail which led me to a number of ancestry trees. None of them had the person who arrived early because none of the trees went that far back. I knew their trees were descendants of the right family because I was able to track them from Canada to the US through the Census (they had immigrated together in families) and then through the records.

    My uncle took Ancestry’s DNA and voila!! I instantly recognized those matches who had the trees that I had researched.
    I have not found any vital record for my uncle’s 2gr-grandfather whose parents are still a mystery BUT because of the number of matches, I HAD thought that the family who arrived were either his parents or aunt/uncle – and NOW, I’m not so sure after reading – “Just because you share DNA with 10 descendants of Ancestor Z, this does not mean that you have to be his descendant. There are always other explanations for shared DNA.”

    A few cousins on our side of the family are a match (descend from 2gr-grandfather’s son)..
    Other distant cousins (descend from 2gr’s daughter) are also matches.

    My uncle’s best match is Francis @ 37 cM.(appears to be same generation as my uncle)
    w/ 13 shared matches which include my uncle’s sister, my children, a handful of my distant cousins and
    two other descendants.

    So is there a chance then that we’re NOT related?? ??

    • Diahan Southard

      There are other steps before claiming victory. This blog describes confirmation bias and some steps to take to make sure what you are seeing fits your theory. Everyone involved needs to have complete trees, the genetics must fit the genealogy for all of the matches and a thorough genetic researcher looks for matches on every line that descends from the proposed shared ancestor. At 37cM, there are many possible relationships, including half-relationships that need to be taken into account. The Skills class would be a great next step for you.


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