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, 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. Using DNA relationships we have identified the correct people in each line and documented the relationships among lines.
Our work is based on the concepts identified by the International Society of Genetic Genealogy. As the Duke study has now grown to many participants we evolved to use wikitree.com to capture the growing 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 encourage you to post your own matches for your siblings and near cousins using the wikitree.com DNA confirmation guidance so that your lineage will be fully DNA verified.
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 multiple people from your line join our effort is critically important for drawing relationship conclusions. Note that my website is for my own personal research and does not include the results of the Duke DNA Study which are circulated privately with results posted on wikitree.com.
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.com (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:
--name of earliest known Duke ancestor
--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 wikitree.com in the next phase.
Phase four: add your Duke direct-line lineage to the tree we are building on wikitree.com 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.
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.