Ancestry at 23andMe: Finding Connections

In our last post, Sheridan* responded to her potential fifth cousin Akina and discovered that she has a potential second cousin through 23andMe’s Relative Finder feature. All of this is exciting, but she’s definitely starting to feel her lack of genealogy experience catching up with her. When she logs into her account next, though, she finds a message from her friend Brian:

Hi Sheridan!

Did you notice that 23andMe predicts us as 4th cousins?? How cool! We should chat about this sometime. Won’t our parents be amused!

Cheers,
Brian

In fact, Sheridan had been so focused on Akina’s contact request and her exciting second cousin match that she’d totally missed the match a few rows down listing “Brian Killoran” as her potential fourth cousin! She and Brian had grown up together and their parents were still good friends. Sheridan thinks it’s wonderfully ironic given that she’d considered the Killorans as much family as her own. It’s also quite fortuitous because Brian recently developed an interest in genealogy and could show her a bit of what he’s learned. With his help, she might just find out who their shared ancestor was.

Sheridan calls Brian up and they agree to meet at the coffee shop down the street. Once there, they set up their laptops side by side and log in to their individual accounts. Brian asks if she’s checked out any of the Ancestry Labs, but aside from reading about the Haplogroup Tree Mutation Mapper (see Sheridan’s introduction to haplogroups), she hasn’t.

“Oh, yeah,” he nods, “Haplogroup Tree Mutation Mapper is a personal favorite of mine. But right now, the buzz is all around Countries of Ancestry.”

He clicks on Ancestry Tools > Countries of Ancestry in his account and shows Sheridan.

“Each of the grey bars is a chromosome,” he explains, “And these colored bits are parts of your DNA that you have in common with other people because of shared ancestry. The different colors represent countries where people’s grandparents were born, so this tells you potential ancestry for different parts of your DNA.”

“But how does it know where people’s grandparents were born?” Sheridan asks.

Brian clicks on a link near the top that says “see how this works” and a detailed description appears.

“Ah,” she says, reading the first paragraph, “So Countries of Ancestry matches are actually Relative Finder matches, and the country information comes from people’s responses to the ‘Where Are You From?’ survey.” She falls quiet for a moment, eyes lingering wistfully over those words.

Brian gives her a gentle nudge.

“Shall we take a look at yours?”

“Oh – yes, of course!”

Eager to see what her own Ancestry Finder shows, Sheridan opens hers up, but to her disappointment, she only sees a handful of colored bars.

“I usually change the settings to show the most matches. Try changing some of yours,” he suggests, pointing to the area under “Advanced Controls”.

She drags down the minimum segment size and chooses a smaller minimum number of grandparents, and her chromosomes immediately light up with a rainbow of colors.

“How about this one?” she asks, checking off a setting that says, “Include matches primarily from the US, Canada, Australia, New Zealand & South Africa.”

Her chromosomes fill up almost completely with blue colored bars.

“Well, people being born in the U.S. and these other countries doesn’t really say much about ancestry since people moved to these countries from all over,” Brian explains. “But you share a lot of DNA with people whose families have been in America for a while. It’s not always that useful to see.”

For Sheridan, though, even that bit of knowledge is interesting.

After a moment, Sheridan asks, “What about you? We’re supposedly fourth cousins, so does that mean you’re on here somewhere?”

“Hmm.” Brian squints at her screen. “Well, my four grandparents were all born in Ireland, so maybe if we clean this up a little…”

He moves the minimum number of grandparents back up to four. Almost all of the colored bars vanish. Of the ones that remain, Brian drags the mouse over to a strip of four pinkish-red colored bars on chromosome 10.

“This is probably me,” he says.

“Wait-” Sheridan taps his arm and points to chromosome 20. “What about that over there?”

“Oh, you’re right, that could be me, too.” Brian scratches his head. “I know!”

He goes back to his account and clicks on Family Traits. “This tool compares two people and shows where you share DNA.”

The screen shows another view of the 23 pairs of chromosomes. Brian selects Sheridan’s name from a drop-down list of his shares and a bright blue strip representing a half-identical region of DNA appears on chromosome 20.

“So I guess that means I’m actually those pink bars on chromosome 20!” he says.

Sheridan is impressed at this level of detail, but still wondering if they can figure out their ancestral connection. For that, Brian says, they’ll need to go hunting the old-fashioned way. Although his own parents weren’t born in the United States, he knows that some of his ancestors immigrated here in the late 1800’s and he’s been collecting whatever historical records he can find. They decide to meet up again in a few days after he’s looked through his files.

In the meantime, Brian suggests that she contact her second cousin match. “Maybe it will give us a clue about our ancestral connection,” he says, “but even if it doesn’t, it’s still a clue about your family tree.”

With this encouragement, Sheridan clicks “make contact” and sends a customized introduction to her predicted second cousin:

Hello,

My name is Sheridan. 23andMe has identified us as potential 2nd cousins. I’m adopted, and hoping to learn more about my biological relatives! Would you be interested in communicating further to see how we might be related?

Sheridan

She finishes her coffee and bids goodbye to Brian. She can’t wait to see what they can figure out at their next meeting.

* The people and events described in these posts are fictional.