Can DNA help us discover an unknown 4th great-grandfather? In the hopes that it can, I’m returning to my brick wall of identifying Cynthia (Dillard) Royston’s father. The Research Like a Pro with DNA study group is a perfect way to tackle a persistent research question. The structure of the assignments helps me stay on track and the process keeps me moving forward. I’ll be sharing my progress in this series. Will I finally be able to answer the question of who was Cynthia’s father? I don’t know. But I do know that I’ll be one step closer by the end of the study group.
When working with DNA, using the DNA matches of the closest generation to the target ancestor can make all the difference. For this project, I’ll be analyzing the DNA matches of my second cousin, twice removed (2C2R), Victor Parker. While Cynthia is my third great-grandmother, she is Victor’s great-grandmother. He received approximately 12.5 % of her DNA, whereas I only received about 3% or less.
Analyze Your Pedigree
The first step in the RLP with DNA process is to choose a research question. To do this, you analyze your pedigree and decide if you’d like to confirm genealogical relationships in your tree or seek to break down a brick wall by discovering an unknown ancestor.
Although I have several holes in my paternal fan chart (illustrated below), I can only work on one at a time – and this is Cynthia’s time. Marked by a black star, you can see her placement in my paternal line.
Assessing DNA Matches
With my research subject and key tester identified, the next step is to assess the closest DNA matches to the tester. This provides the foundation for the research and helps to make sense of the DNA. Because I am using Victor’s DNA match lists, I needed to gain a sense of his pedigree and DNA matches. Initial clustering of DNA matches into genetic networks or groups of shared matches can be done manually or with an automated program. I used both.
Manual Clustering – Leeds Method
Creating a Leeds Chart for Victor’s DNA matches sharing 90 to 400 centimorgans (cM) confirmed the pedigree collapse I suspected with his southern ancestry. If there is no intermarriage among the family lines, the chart will separate out nicely into four main groups – one for each grandparent. However, if there is intermarriage, DNA matches will connect to the tester in more than one way and the Leeds chart can reflect several groups. In this case, Dana Leeds recommends combining those groups that overlap.
In the Leeds chart that I created for Victor’s DNA, I found that his matches separated into two main groups: Brown /Heal on his maternal line and Parker/Royston on his paternal line. The chart revealed no overlap between maternal and paternal, so that will help me identify the most relevant matches.
Automated Clustering – DNA2Tree
Running the automated clustering program, DNA2Tree, I viewed Victor’s shared matches in a different format. Each cluster revealed a genetic network of DNA matches who share DNA with Victor and each other. My goal is to discover the Most Recent Ancestral Couple (MRCA) of each cluster. The grey squares denote overlap with other clusters and I was able to determine and group the clusters for the maternal Brown/Heal line and the paternal Parker/Royston line. The cluster chart created by DNA2Tree lists surnames found in the DNA matches’ trees, which will help me to further narrow down the MRCA for each cluster.
Adding Matches to Airtable Research Log
In the study group, we use the spreadsheet – database hybrid, Airtable, to organize the DNA information and the final step in the first assignment is to begin entering information about the DNA matches. With the manual and automated clustering done, I started entering the relevant Parker/Royston DNA matches into the “DNA Match Details” table. The table holds information about each DNA match: the amount of shared cM, testing company, links to the DNA match page and the DNA match’s tree, etc. I rely on this log to also hold correspondence and information discovered about each DNA match such as email, Gedmatch kit#, etc. Corraling the information from multiple testing websites makes analysis and correlation much easier.
When I am ready to add documentary research to the project, the Airtable base has a table for the timeline, research log, FANs, etc.
With my first assignment completed, I have a solid foundation for working with Victor’s DNA matches.
If you’re ready to start working on a DNA project, check out our book, Research Like a Pro with DNA: AGenealogist’s Guide to Finding and Confirming Ancestors with DNA Evidence, our online course, or our many blog posts and podcasts about working with DNA.
Best of luck in all your genealogical endeavors!