The purpose of the atDNA Duke Study is to identify Duke families in the southeast US and, using known lineages and atDNA results, to discover linkages among the progenitors and further extend our ancestral lines.  To date almost 200 descendants have been identified for over 20 Duke progenitors in the SE US.

Our work is based on the concepts identified by the International Society of Genetic Genealogy.  When we began our study in Oct 2016 we set a threshold that new participants needed a 10cM level match with other participants to get into the study. As the Duke study has now grown to almost 200 participants and we evolved to use to capture the growing inter-connected lineage data, we no longer use a fixed cM threshold. As you can see from this chart which you can increase in size, fourth to fifth cousins – which form the majority of our cross-family group matches – on average only share about 13cM and 3cM of their atDNA respectively. In fact about 31% of fourth cousins will share no DNA, so having access to your Duke lineage on wikitree is critically important for drawing relationship conclusions. Thus we now do comparisons of new potential participants at about a 7cM threshold. As you can see from reading the wikitree atDNA confirmation requirements, wikitree requires a much stronger cM match before we can post a DNA match there; we post these matches as we identify them and encourage you to post your own as well.


Steps to Join Duke Family atDNA Study:

Phase one: complete atDNA testing with ancestryDNA, MyHeritage, FamilyTreeDNA or 23&Me. Testing techniques vary by company between a cheek swab or collecting a small amount of saliva. For the best prices look for holiday sales.


Phase two: after your atDNA testing results are complete, upload your results on (gedmatch login), a free DNA results repository site where families put their atDNA results to do statistical comparisons and draw genealogical conclusions regardless of the testing company used. Click on  Gedmatch Directions and follow the steps. Provide your gedmatch number to the email at the bottom of this page so we can compare your DNA results to that of other descendants.


Phase three: provide the following data for our study participant sheet:

--gedmatch number

--name of earliest known Duke ancestor

--email address

--URL for your tree

We will next verify our understanding of your lineage with you.  The reason we do this for each new participant is because we need to make certain we have the correct information available to the study leadership who may not be able to access your tree online and to ensure we know what you will be adding to our existing work on in the next phase.


Phase four: add your Duke direct-line lineage to the tree we are building on  Use their help function or contact us if you get stuck.

--set up your wikitree profile following the wikitree steps to add basic info about you

--agree to the honor pledge stating you will contribute research

--click on the Privacy tab and set your privacy level to Public Biography & Tree so we can see and add atDNA comparison data to your profile. What the public will see will be your name, the decade in which you were born, and when you add it your lineage. If you do not set this level we cannot see your profile and lineage or post match data to your profile.

--on the same Privacy tab, scroll down and add the emails for the Duke study leadership to your profile so we can add comparison results to your profile; we will provide you the leadership emails via email.

--add your ancestors for your specific Duke line, stopping to connect where you find someone has already added your ancestor to avoid duplicates. To accomplish this you may need to add 3 or 4 ancestors or 6 to 7 ancestors depending on how much of your lineage has already beeen added to wikitree. For each ancestor you add you need to add a specific source such as a census record or birth, marriage, death certificate citation; you can usually find these for free on

--after your profile is approved by wikitree (could be quick or take 24 hours) add your gedmatch number on the upper right so we can add DNA match statements to your profile.  This is a bit tricky so here are the steps to get to the correct page.  On your profile page in the upper right side of the page you will see "My WIKITREE", "surname-xxxx", "Add", "Find" and "Help" buttons. (If you do not see MY WIKITREE ask us to send another email to you to confirm your account.)  As you move your mouse over these buttons, you will see a drop-down list.  Move your mouse over the "surname-xxxx" button and select "DNA" from the drop-down list.  At the top of the next page you will see "DNA Ancestors", "DNA Descendants" and "DNA Tests" buttons, and click on the "DNA Tests" button.  The next page will display your current tests list and you will see "Edit Or Enter More Details" button, which you click on. The next page will show where you can enter your GEDmatch ID.  Type in your alphanumeric 7 to 8 digit gedmatch kit number and click on the green "SAVE DETAILS" button.

This page shows an example of a public profile with attached ancestors and sources for Julia Dukes. The DNA section on the center left shows atDNA matching data we have added that prove the progenitor is Julia's ancestor. The bottom left shows sources. The far right shows by gedmatch number descendants of this Duke progenitor who are in our study.


Phase five:

Based on comparing your DNA results to the results of others in the study we will identify both your Duke matches and your non-Duke matches.  We have numerous study participants who we have discovered are related to each other on non-Duke lines. In regard to your non-Duke matches, which we exclude from our analyses, we will put you in contact with your non-Duke relatives in our study in case you want to work on those lines together.   As you have time, consider adding your ancestors' spouses to wikitree so we can further eliminate matches that are non-Duke.

For your Duke matches the study leadership will provide you and explain the significance of your atDNA comparison data, post significant DNA matches to your and your ancestors' wikitree profiles, and identify potential ancestral connections based on our study data.