Mark Davis wasn’t looking in his DNA test results for a new birth grandfather, so he didn’t see one–until he started looking at his results in the way Diahan Southard teaches in Your DNA Guide–the Book.
Diahan Southard and Mark Davis at RootsTech 2025, where he told her his story.
“I’ve been involved in genealogy for about 45 years, and I thought I knew my family really, really well,” Mark says. But his confidence–and knowledge–was challenged when he attended one of Diahan’s presentations at RootsTech 2024.
“She challenged us on the way we were doing our DNA matches on Ancestry. At first, I kind of was like, ‘Okay, what am I gonna learn, having been on AncestryDNA since the beginning?’ But as it turned out, she was right. I was doing it wrong.”
“I immediately came back to my booth here at RootsTech and I started looking at those unmatched people I’ve been ignoring. And per her suggestion, I looked for commonalities.”
What he discovered would change everything he thought he knew about his family. At least, on one branch.
“I found out they all belonged to one of two families. And those two families matched at the great-grandparent level for me,” Mark explained. Following the techniques Diahan outlines in Your DNA Guide—the Book, Mark began building out the family trees of these mysterious matches.
“I built out the tree while I was here at RootsTech, I ran it through, and lo and behold, my dad matched with a new father,” he says, his voice conveying the magnitude of this discovery. “Talk about an unexpected person in my family!”
He knows from family lore that his grandmother’s life was difficult. “Her husband had a lot of problems with alcohol, with fighting. He was in jail a lot. She was basically a single mom who had been whipped and beaten and held to the ground and kicked.”
Mark’s detective work continued as he pieced together how her connection to the birth father–Robert Murphy–had occurred. “I started looking….How would they have met? They lived in different counties. I had to try and figure out, how did these people get together.”
Through careful examination of census records, Mark discovered that his grandmother and Robert had been neighbors in 1930. Further research revealed that she had also worked in his restaurant. “Between being neighbors and working for this man, at some point–I don’t know if it was consensual or not, we’ll never know–but what we do know is that somehow they got together. And from that twins were born. My dad and my uncle.”
“I looked up Robert’s picture, and he looks just like my dad at that age. Like, unbelievably,” Mark shares. “His parental figure in the family [the father who raised him] was blonde. This guy’s got black hair. My dad had black hair. My dad had prominent features. This guy had the same features.”
Robert Murphy, left, and James Davis, right (shared with permission).
Making this discovery wasn’t without emotional challenges. “I grieved for quite a while for my research, because when you spend that long researching one quarter of your family tree and then you find out that you have no blood relations to these people, there was a grieving point,” Mark admitted. “I questioned my abilities as a genealogist. I should have been a better genealogist. I should have known this. I should have seen this.”
In hindsight, Mark recognized the clues that had been there all along. “I even talked to one of these ladies one time. We traded emails three or four years ago, and I said, ‘God, we seem to share a lot of DNA, can I look at your tree?’ And she looked at mine and we’re like, ‘I don’t know.’ ‘I don’t know either. Eh, just a fluke.’ You know? And common sense should have told me there, it’s DNA, it’s literally right there in front of you. It doesn’t screw up.”
When Mark shared this discovery with his elderly father, the response was surprising. “I did tell my dad about it, and he was thrilled,” Mark revealed. “He was sad because the grandparents he thought he knew weren’t his blood grandparents, but he said, ‘to know that I’m not carrying the DNA of somebody I have no respect for is huge.'”
This discovery has given Mark a whole new direction for his research. “They’re a potato famine family from Ireland,” he says. “All my other ancestors were pre-Revolutionary War. So, all of a sudden, I have this whole new situation. I have recent Irish ancestry, which is fascinating. After all these years, I feel energized again about my family.”
Mark’s story demonstrates why learning to properly group and analyze your DNA matches using the techniques taught in Your DNA Guide—the Book is so important. As Mark says, “If I hadn’t sat through Diahan’s class, I never would have taken the time to sit down and find that. And it totally turned my research in a different direction.”
Whether you’re trying to break through a brick wall in your research or simply wanting to understand your DNA test results better, the match grouping techniques in Your DNA Guide–the Book provide a clear path forward. A path that, like Mark, you may not have even known to look for.
This blog post was drafted with the assistance of AI technology. (The story is real!)
