The purpose of the DNA Duke Study is to identify Duke and Dukes families and, using known lineages and atDNA and yDNA results, to discover linkages among the progenitors, solve genealogical roadblocks and extend our ancestral lines.  To date about 175 descendants have joined our efforts from over 22 Duke progenitors in the SE US and overseas.  Using genetic genealogy we have identified the correct people in family lines and documented the relationships among lines.  This study has been underway since Nov 2016.

A participant must have sufficient documentation of descent so they can reliably be assigned to the line being studied. Therefore it is important they have at least one ancestor with the surname of the study on their tree. 

Trees with significant gaps in recent generations are an issue.  A tree which is incomplete for the first approximately five to seven generations could mislead us to assume that shared DNA matches are from a Duke ancestor when instead the match could be from another unidentified non-Duke ancestor.

Genetic genealogy is the application of DNA evidence to historical genealogy research.  Our study applies DNA results as evidence of descent based on identifying and assigning segments of DNA shared by two or more individuals descended from the ancestors being studied. 

Genetic genealogy is a complex subject that can only be mastered with study and practice.  Our team of five leaders has the skills necessary to understand how to analyze massive DNA comparisons and to present DNA evidence as one of the sources supporting a genealogical tree.  We encourage you to read some of the many blogs, websites and books that provide insight to this field.

This study includes anyone strongly matched to the study participants, whether their ancestor's surname is Duke or Dukes.

DNA inheritance patterns are random. Some direct line descendants do not inherit DNA from a particular ancestor or do not share any of the DNA they did inherit with another sibling or cousin and thus will not be helpful to our study which is based on cousin matching using both atDNA and yDNA results.

In every case the DNA results of the oldest generation in a family line will have the strongest DNA results, thus for example it is best if the study uses your parent’s DNA results rather than yours.

Our work is based on the concepts identified by the International Society of Genetic Genealogy.  As the study grew we evolved to use to capture the evolving inter-connected lineage data. We use wikitree's 7cM  threshold as a benchmark for confirming relationships; we post your furthest triangulation matches on wikitree as we identify them; and we encourage you to post your own matches for your siblings and near cousins using the DNA confirmation guidance so that your line can be fully DNA-verified. 

As you can see from this chart which you can increase in size, fourth cousins – which form the majority of our cross-family group matches – on average only share about 13cM of their atDNA. In fact about 31% of fourth cousins will share no DNA, so having multiple people from your extended family join our effort is important for drawing relationship conclusions. 

Note that my website is for my own personal research and does not include the results of the study which are circulated privately with conclusions posted on  Any descendants of the study participant can be auxiliary members and receive all study documentation 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.

For males with the Duke/Dukes surname if you have already completed yDNA testing we need your FTDNA kit number.  It would be very helpful if males with the surname who have not yet tested would take a yDNA test with FTDNA up to the Y-111 marker test. It's expensive so its best to wait for a sale.


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

--gedmatch number

--your lineage back to your earliest known Duke ancestor

--email address

--URL for your tree if you have one

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.  We also want to identify any non-Duke matches you have to other descendants.


Phase four: add your Duke direct-line lineage to the tree we are building on using these wikitree directions.

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 from our study which we added to support confirmation Julia is the ancestor of these descendants. The bottom left shows sources. The far right shows by gedmatch number descendants of this Duke progenitor who are in our study.


Phase five:

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.

Based on comparing your DNA results to the results of others in the study we will also identify your non-Duke matches because we have numerous study participants who 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, IF we believe you do not already know these people from participating in our other family line studies.  As you have time, consider adding your ancestors' spouses to wikitree so we can further eliminate matches that are non-Duke.