When biological grandparents are unknown, turning to DNA and genealogical records may help solve the mystery. 

Tara had only been researching her family tree for about a year when she made a startling discovery.

“My dad was adopted by his [own] paternal grandparents at a young age,” she explains. The grandfather/adoptive father was surnamed Carter. ”He was one of 11 children, eight of whom were boys. So I assumed I should find lots of Carter DNA cousins. I signed up to every [DNA testing] site and none appeared.” It was looking like her father was possibly not genetically connected to his paternal relatives.

Finding Biological Grandparents

After making this unexpected discovery, Tara followed a series of steps, each responding to what she learned along the way, which she learned and applied in the intensive DNA Skills Workshop. (Some of these steps are also laid out in the Workshop’s textbook, Your DNA Guide—the Book, which helps DNA testers follow their own unique, step-by-step investigative process.)

1. Ask more relatives to take DNA tests

Tara first asked a handy close relative to test. “My dad had a half-brother (same birth father) and so I got him to test. When the half-brother’s results came back, he didn’t share a single [bit of DNA] with my dad but he did with other Carter cousins.”

So the half-brother was biologically connected to the Carters—and her father likely was not.

2. DNA ethnicity clues

Tara switched her attention next to her dad’s DNA ethnicity results. In many instances, ethnicity can’t help meaningfully with tree-building, but sometimes it can. “I looked at my dad’s ethnicities on AncestryDNA and he was 52% England and North Western Europe with a [genetic] community in East of England,” she says.

When going back a generation, she made an important observation: “My dad’s mum did not have English ancestry in the last 3-5 generations, for which I had confirmed her genealogical paper trail with DNA cousin matches in South Africa. So I started with a hypothesis that my dad’s [now-mystery] biological father was from England, or recently descended from an English ancestor.”

“I focused on his DNA matches who shared the same heritage and landed up on a third cousin at Ancestry who had only one person in his tree who had travelled to South Africa,” she says. This man was Omar Swanson. Could Omar have been the birth father (or his paternal ancestor) who would have met up with the birth mother in South Africa?

“Omar’s parents were Robert Swanson and Lois Lamott,” she learned. “I started trying to track down more information on Omar but was hitting brick walls.”

3. Y DNA haplogroup clues

It was time to pivot again in her research—this time back to DNA. Tara was looking for a man’s birth father, so she turned to YDNA, which reveals details only about paternal-line ancestors. Her father took a YDNA test from Family Tree DNA*, the only company to offer this service for family history.

His test results included a haplogroup assignment. Like autosomal ethnicity results, haplogroups don’t generally lead directly to family tree answers. But Tara was becoming skilled at leveraging every possible clue. So she joined a haplogroup project.

“I contacted the haplogroup administrator on Family Tree DNA for I-M253, my dad’s Y DNA haplogroup. I-M253 is not a super common haplogroup. My dad didn’t have any Y-DNA matches at all.” (That’s not uncommon, unfortunately. Sometimes you have to find your own possible matches and ask them to test, as you’ll see she did later on.)

4. Digging deeper with autosomal DNA

Tara continues. “Working together using autosomal DNA and the What Are the Odds? tool, we tracked down other cousins sharing a possible paternal line back in time further up the Swanson line to Omar Swanson and his parents and so on. We also…tried to also find maternal cousin matches (such as matches to Omar’s wife Lois and her parents). So we were basically trying to find common ancestral couples.”

Meanwhile, another round of targeted testing finally yielded a YDNA match. “A third cousin match on Ancestry did a YDNA test and…at 111 markers he matched my dad on 110! So together with the autosomal DNA, it was looking very likely my dad was biologically a Swanson, not a Carter.”

5. Genealogy + genetics = success

Eventually, sleuthing in old records led to Omar Swanson. “I discovered Omar’s dad had died when he was 4 years old. His mum remarried a Howard. On the 1891 census Omar was down as son of Swanson, but from that date on he started calling himself ‘Omar Howard.’ I was now able to track him in South Africa.”

“He married a Jacobs and…you guessed it…my dad has autosomal DNA cousin matches to the Jacobs line, backed up by genealogy! The Jacobs-Howard(Swanson) couple had a son, George Howard. Well, George was in the right location at the right time to have fathered my dad.”

Even better—and now we’re back to the DNA again—

”On MyHeritage, my father had a possible half-brother! The half-brother had not done DNA but he had the Howard-Jacobs couple in his tree! I was of course super nervous about contacting this potential half-brother. I spoke with DNAangels.org for some advice.”

“To shorten the remainder of the story, my dad who is 83 met his half-brother who is 79 about 2 months ago. His name is Kevin. They get on like a house on fire and meet each other every week for ‘catch-ups.’ Kevin says he doesn’t need a DNA test to know we are all related—apparently my dad looks exactly like Kevin’s grandad—but he has taken a test and we are waiting on the results which will prove beyond all doubt that Kevin is my dad’s half-brother.”

Update: We heard again from Tara, and the DNA test confirmed the relationship! She event went to South Africa and met the family!

Tara’s discovery seems so straight-forward: finding a half-brother through DNA testing. But it wasn’t that simple for her. She had to figure out for herself who her biological grandfather might be, and then find the right person to take a DNA test to confirm her research. Her story is a great reminder that it’s important to do both the genetics and the genealogy!

Tara’s name and those of her relatives and ancestors were all changed to protect privacy. But their story is true.

You Can DO the DNA—and We Can Help

Whatever your DNA questions, your own road to discovery may have similar stops—but also unique twists and turns. Like learning to drive, doing DNA takes patience, dedication, curiosity and a good driver’s ed program. We’re the driver’s ed teachers. (But we’re way more fun than OUR driver’s ed teachers were.) Get started with our free guide to finding birth relatives using DNA.

Free guide: Finding birth relatives with DNA