<img loading="lazy" decoding="async" class="alignright size-full wp-image-7604" title="ancfinder_tutorial_mixed_advanced_controls" src="https://blog-api.23andme.com/wp-content/uploads/2010/10/ancfinder_tutorial_mixed_advanced_controls.png" alt="" width="258" height="148">
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:
<blockquote>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</blockquote>
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.

<img loading="lazy" decoding="async" class="aligncenter size-full wp-image-7628" style="margin-top: 15px; margin-bottom: 15px;" title="sheridan-relfinder-brian" src="https://blog-api.23andme.com/wp-content/uploads/2010/10/sheridan-relfinder-brian1.png" alt="" width="455" height="108" srcset="https://blogcms.23andme.com/wp-content/uploads/2010/10/sheridan-relfinder-brian1.png 455w, https://blogcms.23andme.com/wp-content/uploads/2010/10/sheridan-relfinder-brian1-300x71.png 300w" sizes="auto, (max-width: 455px) 100vw, 455px" />
<div style="margin-bottom: 15px; padding: 10px; background-color: #ffc;">Jan 2013 &#8211; Editor&#8217;s note: Ancestry Finder is now known as Countries of Ancestry. &nbsp;Ancestry Labs is sometimes known as Ancestry Tools. Family Inheritance is sometimes known as Family Traits. &nbsp;This post has been updated to reflect these changes. Certain images of Relative Finder may be out of date as this story was created prior to Relative Finder&#8217;s Summer 2011 update.</div>
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 <a href="https://blog.23andme.com/2010/09/29/ancestry-at-23andme-introducing-sheridan/">introduction to haplogroups</a>), 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 &gt; Countries of Ancestry in his account and shows Sheridan.
<img loading="lazy" decoding="async" class="aligncenter size-full wp-image-7626" title="brian-ancfinder-full" src="https://blog-api.23andme.com/wp-content/uploads/2010/10/brian-ancfinder-full1.png" alt="" width="638" height="426" srcset="https://blogcms.23andme.com/wp-content/uploads/2010/10/brian-ancfinder-full1.png 912w, https://blogcms.23andme.com/wp-content/uploads/2010/10/brian-ancfinder-full1-300x200.png 300w, https://blogcms.23andme.com/wp-content/uploads/2010/10/brian-ancfinder-full1-768x513.png 768w, https://blogcms.23andme.com/wp-content/uploads/2010/10/brian-ancfinder-full1-880x588.png 880w" sizes="auto, (max-width: 638px) 100vw, 638px" />
“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&#8217;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 &#8216;Where Are You From?&#8217; survey.” She falls quiet for a moment, eyes lingering wistfully over those words.
Brian gives her a gentle nudge.
&#8220;Shall we take a look at yours?&#8221;
&#8220;Oh &#8211; yes, of course!&#8221;
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.
<img loading="lazy" decoding="async" class="aligncenter size-full wp-image-7598" title="sheridan-ancfinder-noUS" src="https://blog-api.23andme.com/wp-content/uploads/2010/10/sheridan-ancfinder-noUS.png" alt="" width="602" height="567" srcset="https://blogcms.23andme.com/wp-content/uploads/2010/10/sheridan-ancfinder-noUS.png 781w, https://blogcms.23andme.com/wp-content/uploads/2010/10/sheridan-ancfinder-noUS-300x283.png 300w, https://blogcms.23andme.com/wp-content/uploads/2010/10/sheridan-ancfinder-noUS-768x724.png 768w" sizes="auto, (max-width: 602px) 100vw, 602px" />
“How about this one?” she asks, checking off a setting that says, “Include matches primarily from the US, Canada, Australia, New Zealand &amp; 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&#8230;”
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.
<img loading="lazy" decoding="async" class="aligncenter size-full wp-image-7596" title="sheridan-ancfinder-brian" src="https://blog-api.23andme.com/wp-content/uploads/2010/10/sheridan-ancfinder-brian.png" alt="" width="631" height="373" srcset="https://blogcms.23andme.com/wp-content/uploads/2010/10/sheridan-ancfinder-brian.png 751w, https://blogcms.23andme.com/wp-content/uploads/2010/10/sheridan-ancfinder-brian-300x177.png 300w" sizes="auto, (max-width: 631px) 100vw, 631px" />
“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.”
<img loading="lazy" decoding="async" class="alignleft size-full wp-image-7619" title="sheridan-inheritance" src="https://blog-api.23andme.com/wp-content/uploads/2010/10/sheridan-inheritance.png" alt="" width="356" height="213" srcset="https://blogcms.23andme.com/wp-content/uploads/2010/10/sheridan-inheritance.png 356w, https://blogcms.23andme.com/wp-content/uploads/2010/10/sheridan-inheritance-300x179.png 300w" sizes="auto, (max-width: 356px) 100vw, 356px" />
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.
<img loading="lazy" decoding="async" class="aligncenter size-full wp-image-7600" title="2ndcuz-contact" src="https://blog-api.23andme.com/wp-content/uploads/2010/10/2ndcuz-contact.png" alt="" width="236" height="82">
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:
<blockquote>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</blockquote>
She finishes her coffee and bids goodbye to Brian. She can’t wait to see what they can figure out at their next meeting.
<div style="background-color: #ffc; padding: 15px; margin-top: 10px; margin-bottom: 10px;">
Other posts in this series:
<a href="https://blog.23andme.com/2010/09/16/ancestry-at-23andme-what-can-you-learn/">What Can You Learn?</a> &#8211; An overview of 23andMe&#8217;s ancestry features.
<a href="https://blog.23andme.com/2010/09/29/ancestry-at-23andme-introducing-sheridan/">Introducing Sheridan</a> &#8211; We meet Sheridan and she learns about her maternal haplogroups.
<a href="https://blog.23andme.com/2010/10/08/ancestry-at-23andme-sheridans-global-origins/">Sheridan&#8217;s Global Origins</a> &#8211; Sheridan compares herself and her friends to various populations around the world.
<a href="https://blog.23andme.com/2010/10/15/ancestry-at-23andme-sheridans-got-relatives/">Sheridan&#8217;s Got Relatives</a> &#8211; Sheridan responds to a fifth cousin and discovers a predicted second cousin in the 23andMe database.
(next) <a href="https://blog.23andme.com/2010/10/29/ancestry-at-23andme-old-roots-and-new-horizons/">Old Roots and New Horizons</a> &#8211; Sheridan and Brian put together the pieces to sketch out their shared family tree.
</div>
* The people and events described in these posts are fictional.

23andMe Blog

23andMe Blog Team

Ancestry at 23andMe: Finding Connections

<img decoding="async" class="alignright size-full wp-image-7533" title="relfinder_matches" src="https://blog-api.23andme.com/wp-content/uploads/2010/10/relfinder_matches.png" alt="" width="335" srcset="https://blogcms.23andme.com/wp-content/uploads/2010/10/relfinder_matches.png 460w, https://blogcms.23andme.com/wp-content/uploads/2010/10/relfinder_matches-300x91.png 300w" sizes="(max-width: 460px) 100vw, 460px" />
We’ve been following Sheridan’s* journey through the ancestry features at 23andMe over the last few weeks. Because she was adopted with no record of her biological parents, every piece of information has been eye-opening for her. So far, she’s learned that her <a href="https://blog.23andme.com/2010/09/29/ancestry-at-23andme-introducing-sheridan/">maternal haplogroup is H2a</a>, meaning that her biological mother’s ancestors were likely European, and potentially Eastern European. She’s also learned that, overall, <a href="https://blog.23andme.com/2010/10/08/ancestry-at-23andme-sheridans-global-origins/">her genome is most similar to Europeans</a>, followed closely by Northern Africans. Her closest mapping to indigenous populations around the world is with the Mozabites of Northern Africa. But because she may have a mixed background, she knows that this mapping needs to be interpreted as an average of where her biological ancestors were from.
When we last left her, Sheridan had received a request through 23andMe to connect with a potential 5th cousin. What does this actually mean? Well, for one thing, it means that someone has enough DNA in common with Sheridan to be predicted as a 5th cousin using 23andMe’s Relative Finder feature.
Although contacting a potential 5th cousin isn’t quite the same as contacting a biological parent, Sheridan has never contacted any biological relatives before and so is understandably a little bit anxious. Having called it a night after exploring her Global Similarity results, she now takes a deep breath and opens the contact request email.
<blockquote>Hello,
23andMe predicted that we might be 5th cousins! I am African-American and have some genealogical records that I’m willing to share if you’re interested in trying to figure out how we might be related.
Would you be interested in communicating further?
Sincerely, 
Akina</blockquote>
<img loading="lazy" decoding="async" class="alignright wp-image-7534 size-medium" title="5thcousin-videoshot" src="http://35.88.189.111/wp-content/uploads/2010/10/5thcousin-videoshot-300x222.png" alt="" width="300" height="222" srcset="https://blogcms.23andme.com/wp-content/uploads/2010/10/5thcousin-videoshot-300x222.png 300w, https://blogcms.23andme.com/wp-content/uploads/2010/10/5thcousin-videoshot.png 596w" sizes="auto, (max-width: 300px) 100vw, 300px" />
Sheridan is astounded. Here is what is apparently an African-American woman with genealogical records who could be her 5th cousin! She isn’t sure how to respond right away, especially since she’s new to this whole thing and doesn’t even know what a 5th cousin is. Luckily, 23andMe has an educational video titled “<a href="https://www.youtube.com/user/23andMe#p/u/0/qG6BFjoXHvY" target="_blank" rel="noopener noreferrer">Just What Is A Fifth Cousin?</a>” which explains very clearly what being 5th cousins means &#8212; that she and Akina might share great-great-great-great grandparents. As Sheridan thinks about this a bit more, she realizes that the ancestor that might connect her and Akina would have to have lived around 140-160 years ago.
She still has no idea how to figure out their connection, but is willing to give it a try, so she accepts Akina&#8217;s request with a quick message:
<blockquote>Akina,
I&#8217;m new to all this, and I don&#8217;t know if I can contribute much to the search because I&#8217;m adopted. But I&#8217;m eager to learn more about my &#8212; our? &#8212; family tree!
Sheridan</blockquote>
And just how can 23andMe tell whether Sheridan and Akina might be 5th cousins? Two major pieces of information go into 23andMe’s Relative Finder predictions: the % of DNA shared and the number of segments shared between people in the 23andMe database.
<img loading="lazy" decoding="async" class="alignright wp-image-7535 size-medium" title="recombination" src="http://35.88.189.111/wp-content/uploads/2010/10/recombination-300x261.png" alt="" width="300" height="261" srcset="https://blogcms.23andme.com/wp-content/uploads/2010/10/recombination-300x261.png 300w, https://blogcms.23andme.com/wp-content/uploads/2010/10/recombination-768x667.png 768w, https://blogcms.23andme.com/wp-content/uploads/2010/10/recombination-1024x890.png 1024w, https://blogcms.23andme.com/wp-content/uploads/2010/10/recombination-880x765.png 880w, https://blogcms.23andme.com/wp-content/uploads/2010/10/recombination-1180x1025.png 1180w, https://blogcms.23andme.com/wp-content/uploads/2010/10/recombination.png 1204w" sizes="auto, (max-width: 300px) 100vw, 300px" />
Recall that everyone has two copies of each chromosome (except for the X chromosome in men), one from mom and one from dad. These copies exchange analogous segments of DNA with each other &#8212; a process called recombination &#8212; before being passed on to future generations, such that the set of chromosomes you received from your mother (or father) is a mix of the DNA that she got from her parents. Since each parent contributed 50% of your DNA, that means that the % of DNA shared between you and each grandparent is roughly 25%. Every generation you go back will halve the % of DNA shared, on average.
It also turns out that you share roughly the same % of DNA with your parents as you would with a sibling, so how can we tell what type of relationship it is? The number of DNA segments shared is also important &#8212; you would share about 50% of your DNA with a sibling but distributed over many more segments than with a parent. This is because recombination is somewhat random, so you and your sibling received different mixes of DNA from each parent, resulting in a larger number of smaller segments shared between you and your sibling. (The same principle allows us to distinguish between uncle/aunt and grandparent relationships.)
As you go farther back in a family tree to find a common ancestor, the % of DNA and the number of DNA segments shared decreases. Using data gathered from a set of people with known relationships allows us to develop a model to predict what the most likely relationship might be for a new pair of individuals &#8212; like Sheridan and Akina &#8212; using their % DNA and number of segments shared. Although the resolution drops off as predictions become more distant, and the exact type of relationship may not be accurate (e.g. “double cousins”, cousins x-times removed, and other less straightforward relationships are not included in our lists of possible predictions), the prediction is generally in the ballpark.
<img decoding="async" class="alignleft size-full wp-image-7536" style="margin-top: 10px; margin-right: 10px; margin-bottom: 10px;" title="sheridan-relfinder" src="https://blog-api.23andme.com/wp-content/uploads/2010/10/sheridan-relfinder.png" alt="" width="300" srcset="https://blogcms.23andme.com/wp-content/uploads/2010/10/sheridan-relfinder.png 779w, https://blogcms.23andme.com/wp-content/uploads/2010/10/sheridan-relfinder-274x300.png 274w, https://blogcms.23andme.com/wp-content/uploads/2010/10/sheridan-relfinder-768x840.png 768w" sizes="(max-width: 779px) 100vw, 779px" />
Editor&#8217;s note: The image to the left shows the Relative Finder feature prior to the Summer 2011 update. Relative Finder is now also sometimes referred to as <a href="https://www.23andme.com/dna-ancestry/">DNA Relatives</a>.
Sheridan checks the rest of her Relative Finder results (click on image on the left to enlarge) but doesn’t see any matches predicted to be her parents or siblings. Darn! That would have been too easy. As she goes down the list of results, though, Sheridan sees something intriguing. A predicted second cousin? Hovering over this result reminds her that she would share a great grandparent with a second cousin.
Once again, Sheridan is amazed &#8212; and a little nervous &#8212; at what her DNA is able to tell her. She definitely wishes she had more experience researching genealogy to navigate the puzzle pieces of her family tree. But help may be closer than she thinks&#8230;
<div style="background-color: #fff; height: 20px; color: #000;"></div>
<div style="background-color: #ffc; padding: 15px; margin-top: 10px; margin-bottom: 10px; padding-top: 15px;">
Other posts in this series:
<a href="https://blog.23andme.com/articles/ancestry-at-23andme-what-can-you-learn">What Can You Learn?</a> &#8211; An overview of 23andMe&#8217;s ancestry features.
<a href="https://blog.23andme.com/articles/ancestry-at-23andme-introducing-sheridan">Introducing Sheridan</a> &#8211; We meet Sheridan and she learns about her maternal haplogroups.
<a href="https://blog.23andme.com/articles/ancestry-at-23andme-sheridans-global-origins">Sheridan&#8217;s Global Origins</a> &#8211; Sheridan compares herself and her friends to various populations around the world.
(next)  <a href="https://blog.23andme.com/articles/ancestry-at-23andme-finding-connections">Finding Connections</a> &#8211; Sheridan and Brian bond over their fourth cousin connection.
<a href="https://blog.23andme.com/articles/ancestry-at-23andme-old-roots-and-new-horizons">Old Roots and New Horizons</a> &#8211; Sheridan and Brian put together the pieces to sketch out their shared family tree.
</div>
<div>* The people and events described in these posts are fictional. 
</div>

Ancestry at 23andMe: Sheridan’s Got Relatives

<img loading="lazy" decoding="async" class="alignright size-full wp-image-7457" style="border: 1px solid black; margin-left: 10px;" title="gs-leadin" src="https://blog-api.23andme.com/wp-content/uploads/2010/10/gs-leadin.png" alt="" width="312" height="149" srcset="https://blogcms.23andme.com/wp-content/uploads/2010/10/gs-leadin.png 312w, https://blogcms.23andme.com/wp-content/uploads/2010/10/gs-leadin-300x143.png 300w" sizes="auto, (max-width: 312px) 100vw, 312px" />
In <a href="https://blog.23andme.com/2010/09/29/ancestry-at-23andme-introducing-sheridan/">her first ancestry foray</a>, Sheridan* learned about her Maternal Line. Through her friend Mesut, she also learned about the Paternal Line feature. But these analyses only told her about a tiny part of her DNA. Other features at 23andMe use DNA contained in the other 22 pairs of chromosomes &#8212; called autosomes &#8212; and can tell her how similar she is to everyone else in the world and whether any of them are related to her through any branch of her family tree. Join us as Sheridan continues to explore her genetic ancestry.
<div style="padding: 10px; background-color: #ffc; margin-bottom: 15px;">Editor&#8217;s note: This post discusses features that are now obsolete. Global Similarity has been replaced by the new Ancestry Composition feature, and Global Similarity: Advanced is now known as Global Similarity Map. However, many of the concepts and information you can learn from these tools are still applicable.</div>
Since the last time we left her, Sheridan has received two more sharing invitations &#8212; one from her friend Hua who’s had an account at 23andMe for a while and one from a family friend named Brian who signed up at the same time as she did and is interested in genetic genealogy. She gladly accepts, figuring that both friends might help her navigate the features at 23andMe and understand the results. A message from Hua accompanies the sharing request:
“I’m so glad you decided to sign up! I can’t wait to see what your data says. By the way, my personal favorite is Global Similarity: Advanced, especially if you’re sharing with people. It’s really interesting seeing where everyone ends up!”
Sheridan can’t think of a better place to go next, so she clicks on Global Similarity. This tool compares your genome (via the roughly 500,000 SNPs that 23andMe tests) to many other publicly available “reference” genomes from individuals around the world, representing major indigenous world populations.
<img loading="lazy" decoding="async" class="aligncenter size-full wp-image-7474" title="sheridan-gs" src="https://blog-api.23andme.com/wp-content/uploads/2010/10/sheridan-gs1.png" alt="" width="598" height="332" srcset="https://blogcms.23andme.com/wp-content/uploads/2010/10/sheridan-gs1.png 711w, https://blogcms.23andme.com/wp-content/uploads/2010/10/sheridan-gs1-300x167.png 300w, https://blogcms.23andme.com/wp-content/uploads/2010/10/sheridan-gs1-271x149.png 271w" sizes="auto, (max-width: 598px) 100vw, 598px" />
<img loading="lazy" decoding="async" class="alignright size-full wp-image-7460" style="border: 1px solid black; margin-right: 10px;" title="sheridan-gs-bars" src="https://blog-api.23andme.com/wp-content/uploads/2010/10/sheridan-gs-bars.png" alt="" width="246" height="218">
Sheridan immediately notices that her highest similarity is with Northern Europeans. This isn’t that surprising given that her maternal haplogroup indicates probable European ancestry. But she sees that she is also highly similar to African populations, especially Northern Africans. Could this be a clue about her biological father’s origins?
As Sheridan ponders this, her eyes focus on a big, blue button in the top right of the page and she suddenly remembers that Hua had specifically mentioned an “advanced” version of Global Similarity.
<img loading="lazy" decoding="async" class="alignleft size-full wp-image-7469" title="btn_pca_advanced" src="https://blog-api.23andme.com/wp-content/uploads/2010/10/btn_pca_advanced.gif" alt="" width="155" height="34">
Clicking the button takes Sheridan to a more abstract map dotted with clusters of colored squares and larger balloon arrows. Mousing over them, she sees that the green arrow represents herself and the darker arrows her friends. She also notices that each cluster corresponds to a major world population, and clicking on one zooms in to reveal more detailed populations, like the Sardinians of Southern Europe, Mayans of the Americas, and Bedouins of the Near East. In fact, every point on the advanced map (colored square or bubble) corresponds to some person and their genotype. The map arranges all the people/genotypes so that the closer two people are genetically, the closer they appear on the map.
(Click on images to view larger)
<table style="margin: 10px;">
<tbody>
<tr>
<td rowspan="3"><img loading="lazy" decoding="async" class="aligncenter size-full wp-image-7477" title="sheridan-gsa" src="https://blog-api.23andme.com/wp-content/uploads/2010/10/sheridan-gsa.png" alt="" width="310" height="330"></td>
<td><img loading="lazy" decoding="async" class="aligncenter size-full wp-image-7478" title="sheridan-gsa-zoomed" src="https://blog-api.23andme.com/wp-content/uploads/2010/10/sheridan-gsa-zoomed.png" alt="" width="150" height="158" srcset="https://blogcms.23andme.com/wp-content/uploads/2010/10/sheridan-gsa-zoomed.png 474w, https://blogcms.23andme.com/wp-content/uploads/2010/10/sheridan-gsa-zoomed-284x300.png 284w" sizes="auto, (max-width: 150px) 100vw, 150px" /></td>
<td><img loading="lazy" decoding="async" class="aligncenter size-full wp-image-7479" title="hua-gsa-zoomed" src="https://blog-api.23andme.com/wp-content/uploads/2010/10/hua-gsa-zoomed.png" alt="" width="150" height="157" srcset="https://blogcms.23andme.com/wp-content/uploads/2010/10/hua-gsa-zoomed.png 474w, https://blogcms.23andme.com/wp-content/uploads/2010/10/hua-gsa-zoomed-286x300.png 286w" sizes="auto, (max-width: 150px) 100vw, 150px" /></td>
</tr>
<tr>
<td><img loading="lazy" decoding="async" class="aligncenter size-full wp-image-7480" title="brian-gsa-zoomed" src="https://blog-api.23andme.com/wp-content/uploads/2010/10/brian-gsa-zoomed.png" alt="" width="152" height="160" srcset="https://blogcms.23andme.com/wp-content/uploads/2010/10/brian-gsa-zoomed.png 476w, https://blogcms.23andme.com/wp-content/uploads/2010/10/brian-gsa-zoomed-285x300.png 285w" sizes="auto, (max-width: 152px) 100vw, 152px" /></td>
<td><img loading="lazy" decoding="async" class="aligncenter size-full wp-image-7483" title="mesut-gsa" src="https://blog-api.23andme.com/wp-content/uploads/2010/10/mesut-gsa.png" alt="" width="152" height="157"></td>
</tr>
</tbody>
</table>
<div style="float: right; text-align: justified; width: 200px; background-color: #eee; padding: 15px; margin-left: 10px;">
Keep in mind&#8230;
All humans are over 99% identical to each other in their DNA. The smaller percentages we see in Global Similarity (Basic) are due to the fact that we’re only looking at SNPs &#8212; places in the genome that are known to vary in humans. Mousing over all of the reference populations will reveal that the least similar populations are not that different from the most similar population to the person being analyzed.
</div>
Sheridan’s green marker falls near the top of the African region, and zooming in further shows her squarely in the Mozabite population of Northern Africa. She’s not really sure what to make of this, given that her highest similarity is to Europeans. Her friends Hua and Brian, on the other hand, are more straightforward &#8212; Hua lands squarely within the Han Chinese cluster, while Brian is very clearly Irish. Mesut is a little more interesting because he places with the Near Easterners, close to Palestinian individuals but not quite. Sheridan guesses that there isn’t a reference population available that’s closer to Mesut.
Browsing through the informational links on the bottom right side of the page helps Sheridan understand what her placement with the Mozabites of Northern Africa might mean. Every one of us has many ancestors, from potentially many places in the world; what Global Similarity: Advanced does is to locate you on this map roughly at the average of the positions that your ancestors would be placed. For Sheridan&#8217;s Dubliner friend Brian, all of his ancestors are Irish going back five generations, so it&#8217;s not surprising that Brian shows up squarely in the Irish reference cluster. A person with a European dad and a Chinese mom, though, would tend to be plotted about halfway between Europe and China, nearest the reference Central Asian populations.
<div style="background-color: #ffc; padding: 15px; margin-top: 10px; margin-bottom: 10px;">
So Sheridan now finds herself with the following clues: 
 
<a href="https://www.23andme.com/you/haplogroup/maternal">Maternal Line</a> &#8211; H2a. Her mother must have some European ancestry, possibly from Eastern Europe.
Global Similarity &#8211; Highest with Northern and Southern Europeans, then with Northern Africans.
Global Similarity: Advanced &#8211; Mozabite (a Northern African population). Probably represents a genetic location that is intermediate between where her ancestors are from.
</div>
Sheridan’s excited to talk to her friends about what she’s learned but before she can she finds an interesting message in her inbox.
“A potential 5th cousin would like to make contact with you,” it says, making Sheridan’s heart thump.
Tune in next time as we explore Relative Finder and Ancestry Finder, and see who Sheridan’s potential 5th cousin is!
<div style="background-color: #eee; padding: 15px; margin-top: 10px; margin-bottom: 10px;">
Other posts in this series:
<a href="https://blog.23andme.com/articles/ancestry-at-23andme-what-can-you-learn">What Can You Learn?</a> &#8211; An overview of 23andMe&#8217;s ancestry features.
<a href="https://blog.23andme.com/articles/ancestry-at-23andme-introducing-sheridan">Introducing Sheridan</a> &#8211; We meet Sheridan and she learns about her maternal haplogroups.
(next) &nbsp;<a href="https://blog.23andme.com/articles/ancestry-at-23andme-sheridans-got-relatives">Sheridan&#8217;s Got Relatives</a> &#8211; Sheridan responds to a fifth cousin and discovers a predicted second cousin in the 23andMe database.
<a href="https://blog.23andme.com/articles/ancestry-at-23andme-finding-connections">Finding Connections</a> &#8211; Sheridan and Brian bond over their fourth cousin connection.
<a href="https://blog.23andme.com/articles/ancestry-at-23andme-old-roots-and-new-horizons">Old Roots and New Horizons</a> -Sheridan and Brian put together the pieces to sketch out their shared family tree.
</div>
* The people and events described in these posts are fictional.

Ancestry at 23andMe: Sheridan’s Global Origins

<img loading="lazy" decoding="async" class="aligncenter size-full wp-image-7425" style="margin-left: 10px;" title="ancestry-photo-sheridan" src="https://blog-api.23andme.com/wp-content/uploads/2010/09/ancestry-photo-sheridan.png" alt="" width="280" height="152">
Meet Sheridan*. She&#8217;s a 27 year old female who signed up for 23andMe during one of our sales. Adopted at eight months, she has no information about her biological roots and the adoption agency has no records other than where she was found &#8212; on the steps of a church in a small town near Atlanta, Georgia. She otherwise had an uneventful childhood growing up with her loving and supportive adoptive family.
Now married and thinking of having kids of her own, Sheridan wishes more than ever that she knew something about her background. Even simple things &#8212; like her ethnic heritage &#8212; are a mystery to her (the only thing she knows is that she&#8217;s likely to be mixed race). While 23andMe can&#8217;t provide all the answers, its many tools and features might reveal some interesting clues about where Sheridan came from.
Join us as we follow Sheridan&#8217;s journey through Ancestry at 23andMe &#8212; we&#8217;ll release a new clue in each Ancestry how-to post in this series. We&#8217;ll put together the whole story at the end, but feel free to speculate given the clues you&#8217;ve received so far. Top-notch sleuthing wins bragging rights. 🙂

____________________
Sheridan recently got her 23andMe results. She was a little nervous about logging in to see them at first but a few days later she gets a sharing invitation from her friend Mesut, &nbsp;who had agreed to sign up for 23andMe with her.
&#8220;Dear Sheridan,&#8221; it says, &#8220;Mesut Yavas has offered to share the following genetic profile on 23andMe: Mesut Yavas (Complete Edition).&#8221;
An encouraging email from Mesut follows, &#8220;Not certain what exactly this sharing thing is about, so I requested &#8216;Basic&#8217; sharing for now. We must walk before we can run, but soon we will be learning in leaps and bounds. Might as well make the jump, Sheridan! Let our DNA speak to us!&#8221;
&#8220;Well,&#8221; she thinks, &#8220;here goes&#8230;&#8221;
Maternal Line
<img loading="lazy" decoding="async" class="alignright size-medium wp-image-7273" style="padding-left: 10px;" title="female_mt" src="https://blog-api.23andme.com/wp-content/uploads/2010/09/female_mt1-300x225.png" alt="" width="180" height="135" srcset="https://blogcms.23andme.com/wp-content/uploads/2010/09/female_mt1-300x225.png 300w, https://blogcms.23andme.com/wp-content/uploads/2010/09/female_mt1-768x576.png 768w, https://blogcms.23andme.com/wp-content/uploads/2010/09/female_mt1.png 800w" sizes="auto, (max-width: 180px) 100vw, 180px" />
Sheridan&#8217;s a little rusty on her high school biology so she calms her nerves and beefs up her genetics knowledge using 23andMe&#8217;s &nbsp;<a href="https://www.23andme.com/gen101/" target="_blank" rel="noopener noreferrer">&#8220;Genetics 101&#8221;</a> educational material. Then she accepts Mesut&#8217;s sharing invitation and clicks on the first link under &#8220;My Ancestry&#8221;: Maternal Line.
As we mentioned briefly in our &nbsp;first “Ancestry at 23andMe” post, the maternal line is traced through mitochondrial DNA, which is found in the parts of our cells that turn food into energy. All of us inherit our mitochondrial DNA from our mother, and so we can use it to learn something about where our mother&#8217;s mother&#8217;s mother&#8217;s ancestors came from. This is possible because as DNA is passed down through the generations, errors in copying, known as genetic variants or mutations, may occur. A maternal haplogroup is a family of mitochondrial DNA types that traces back to a single mutation in a specific individual, usually representative of a significant event (e.g. a migration or development) in human prehistory.
The first thing Sheridan sees under Maternal Line is a map of the world and her &#8220;Maternal Haplogroup&#8221;, &#8220;H2a&#8221; above it.
<img loading="lazy" decoding="async" class="aligncenter size-full wp-image-7405" style="border: 1px solid black;" title="sheridan-h2a" src="https://blog-api.23andme.com/wp-content/uploads/2010/09/sheridan-h2a.png" alt="" width="516" height="284" srcset="https://blogcms.23andme.com/wp-content/uploads/2010/09/sheridan-h2a.png 516w, https://blogcms.23andme.com/wp-content/uploads/2010/09/sheridan-h2a-300x165.png 300w, https://blogcms.23andme.com/wp-content/uploads/2010/09/sheridan-h2a-271x149.png 271w, https://blogcms.23andme.com/wp-content/uploads/2010/09/sheridan-h2a-372x204.png 372w" sizes="auto, (max-width: 516px) 100vw, 516px" />
The colors on the map indicate where in the world the H2 haplogroups are most commonly found &#8212; at least before oceanliners and 747&#8217;s made intercontinental travel a simple endeavor. The “History” tab at the top of the page has even more information about H2, and H2a specifically; in fact, H2a is especially common in eastern Europe. This is Sheridan’s first concrete clue about her mother&#8217;s ancestry. She&#8217;s also amused to learn that this haplogroup originated in or near what is now Turkey, since this is where Mesut is from.
That&#8217;s when Sheridan notices a list of people on the right side of the page. There&#8217;s &#8220;Chinese Person&#8221; and &#8220;Japanese Person&#8221;, and clicking on them changes the map to show their haplogroups&#8217; global distributions. Mesut is also in the list, since they are sharing genomes with each other at the &#8220;Basic&#8221; level. His maternal haplogroup is HV1, an ancient haplogroup that&#8217;s found across eastern Europe, central Asia, and northern Africa but is relatively rare in modern-day Turkey.
<table border="1" align="center">
<tbody>
<tr>
<td><img loading="lazy" decoding="async" class="aligncenter size-full wp-image-7399" title="mesut-hv1" src="https://blog-api.23andme.com/wp-content/uploads/2010/09/mesut-hv1.png" alt="" width="386" height="213" srcset="https://blogcms.23andme.com/wp-content/uploads/2010/09/mesut-hv1.png 516w, https://blogcms.23andme.com/wp-content/uploads/2010/09/mesut-hv1-300x165.png 300w, https://blogcms.23andme.com/wp-content/uploads/2010/09/mesut-hv1-271x149.png 271w, https://blogcms.23andme.com/wp-content/uploads/2010/09/mesut-hv1-372x204.png 372w" sizes="auto, (max-width: 386px) 100vw, 386px" /></td>
<td><img loading="lazy" decoding="async" class="alignleft size-full wp-image-7401" title="sheridan-matline-shares" src="https://blog-api.23andme.com/wp-content/uploads/2010/09/sheridan-matline-shares.png" alt="" width="235" height="150"></td>
</tr>
</tbody>
</table>
<img loading="lazy" decoding="async" class="alignright size-full wp-image-7402" style="border: 1px solid black; margin-top: 10px; margin-left: 10px;" title="sheridan-mat-tree" src="https://blog-api.23andme.com/wp-content/uploads/2010/09/sheridan-mat-tree.png" alt="" width="214" height="206" srcset="https://blogcms.23andme.com/wp-content/uploads/2010/09/sheridan-mat-tree.png 423w, https://blogcms.23andme.com/wp-content/uploads/2010/09/sheridan-mat-tree-300x290.png 300w" sizes="auto, (max-width: 214px) 100vw, 214px" />
Finally, Sheridan clicks on the last tab at the top of the page, &#8220;Haplogroup Tree&#8221;, revealing a hierarchy of all known maternal haplogroups and their relation to one another through time. From this tree, she sees that haplogroups H2a and HV1 are both descended from haplogroup HV. Since HV split off from its ancestor haplogroup R about 40,000 years ago, this means that Sheridan and Mesut share a common maternal ancestor from around this time &#8212; making them something like 2000th cousins! (Actually, it&#8217;s very likely that they share a more recent common ancestor, but this one we know for sure.)
For 23andMe customers interested in the nitty gritty details, check out the <a href="https://www.23andme.com/you/labs/haplogroup_tree_mut_mapper/" target="_blank" rel="noopener noreferrer">Haplogroup Tree Mutation Mapper</a> under Ancestry Labs (Ancestry Tools). This will show you the SNPs used to define a particular haplogroup, starting with the mutation that defines that haplogroup&#8217;s most recent branch on the tree and working backwards to the root.
Paternal Line
<img loading="lazy" decoding="async" class="alignleft size-medium wp-image-7278" style="padding-left: 10px;" title="male_y" src="https://blog-api.23andme.com/wp-content/uploads/2010/09/male_y1-300x225.png" alt="" width="180" height="135" srcset="https://blogcms.23andme.com/wp-content/uploads/2010/09/male_y1-300x225.png 300w, https://blogcms.23andme.com/wp-content/uploads/2010/09/male_y1-768x576.png 768w, https://blogcms.23andme.com/wp-content/uploads/2010/09/male_y1.png 800w" sizes="auto, (max-width: 180px) 100vw, 180px" />
The paternal line is traced through the Y chromosome, which only males have. This DNA is passed down from father to son and so can tell us something about where a man&#8217;s father&#8217;s father&#8217;s father&#8217;s ancestors came from. Although Sheridan does not have a Y chromosome, she might be able to learn about her paternal ancestry through other 23andMe features. (Note that a woman with known male relatives &#8212; father, brother, paternal uncle, etc. &#8212; &nbsp;can link their Paternal Line information to her account if they are listed as 23andMe connections in the &nbsp;Family Tree feature.)
The results in the Paternal Line analysis are presented similarly to the Maternal Line. Even if you have no Y chromosome, you can still learn about all of the different paternal haplogroups through the sample individuals and Haplogroup Tree. And since Sheridan is sharing with Mesut, she can see his paternal haplogroup, too.
<table border="1" align="center">
<tbody>
<tr>
<td><img loading="lazy" decoding="async" class="aligncenter size-full wp-image-7415" title="mesut-F" src="https://blog-api.23andme.com/wp-content/uploads/2010/09/mesut-F.png" alt="" width="395" height="205" srcset="https://blogcms.23andme.com/wp-content/uploads/2010/09/mesut-F.png 513w, https://blogcms.23andme.com/wp-content/uploads/2010/09/mesut-F-300x156.png 300w" sizes="auto, (max-width: 395px) 100vw, 395px" /></td>
<td><img loading="lazy" decoding="async" class="aligncenter size-full wp-image-7416" title="sheridan-patline-shares" src="https://blog-api.23andme.com/wp-content/uploads/2010/09/sheridan-patline-shares.png" alt="" width="233" height="149"></td>
</tr>
</tbody>
</table>
Scratching the Surface&#8230;
In just five or ten minutes, Sheridan learned some interesting things about where her mother&#8217;s ancestors &#8212; and she, by extension &#8212; might have come from. As a bonus, she was able to find a connection, however ancient, between herself and her friend. Still, the DNA that goes into maternal and paternal line analyses makes up less than 1% of all the DNA that 23andMe analyzes, and those ancestors represent only one or two branches out of a full family tree. To fill out the other branches and the rest of her genome, Sheridan will have to look at the other Ancestry features at 23andMe.
Next time, we&#8217;ll take a closer look at the Global Similarity <del>and Global Similarity:Advanced</del> features, and reveal another clue about Sheridan&#8217;s ancestry as told through DNA.
<div style="background-color: #ffc; padding: 10px;">Summary of 23andMe features mentioned in this post:</div>
<div style="background-color: #ffc; padding: 10px;"><a href="https://www.23andme.com/you/haplogroup/maternal/" target="_blank" rel="noopener noreferrer">Maternal Line</a> — Uses mitochondrial DNA passed down from your mother to trace the origins of your mother’s mother’s mother’s ancestors.</div>
<div style="background-color: #ffc; padding: 10px;"><a href="https://www.23andme.com/you/haplogroup/paternal/" target="_blank" rel="noopener noreferrer">Paternal Line</a> — (Results generated for men only) Uses Y chromosome DNA passed down to sons from their fathers to trace the origins of their father’s father’s father’s ancestors.</div>
<div style="background-color: #ffc; padding: 10px;"><a href="https://www.23andme.com/you/labs/haplogroup_tree_mut_mapper/" target="_blank" rel="noopener noreferrer">Haplogroup Tree Mutation Mapper</a> (Ancestry Labs/Tools) &#8212; Reports the SNPs used to define specific haplogroups.</div>
<div style="background-color: #ffc; padding: 10px;">Keyword: Haplogroup &#8211; A term used to describe individual branches or closely related groups of branches on genetic family trees. Defined by particular genetic mutations that are shared by all the people who belong to the haplogroup.</div>
* The people and events described in these posts are fictional.

Ancestry at 23andMe: Introducing Sheridan

Genetic testing for ancestry is not a concept that most people encounter outside of popular TV shows and so when you hear about services such as 23andMe’s, you might be wondering what exactly it is you’re getting. Even after you’ve signed up and have your data back, you might not know where to start exploring or how to make sense of the wealth of information you’ve just received. Since many people are unfamiliar with genetics and 23andMe offers several unique features, we’ll be presenting a series of posts to help both current customers and the curious reader to understand what you can (and can’t) learn from genetics and from 23andMe in particular.
This first post is part of the “Ancestry at 23andMe” series and is an introduction to the types of information we can tell you about your ancestry. (There will also be a “Health at 23andMe” series to cover the features found in the Health portion of our service.) It may be a review for some, but should help orient those new to genetics or 23andMe (for an even more basic primer, check out our videos in  <a href="https://www.23andme.com/gen101/" target="_blank" rel="noopener noreferrer">Genetics 101</a>). Read on, and let us know if you have a question you would like to see featured in future articles on the 23andMe blog!  
<h6>Ancestry at 23andMe: What Can You Learn?</h6>
<img loading="lazy" decoding="async" class="size-medium wp-image-7225" title="family-tree-labeled" src="https://blog-api.23andme.com/wp-content/uploads/2010/09/family-tree-labeled-300x225.png" alt="" width="300" height="225" /> 
People who have contributed to your DNA.
Using DNA to <a href="https://www.23andme.com/topics/ancestry/family-tree/">uncover clues about your ancestry</a> is a tantalizing prospect for many people. Adoptees and people with diverse ethnic backgrounds may be especially interested in finding out more about where they came from. But even those who have relatively thorough knowledge about their family’s roots may be curious about the more obscure branches of their family tree or the deeper ancestry that connects them to all humans on this planet. Fortunately, DNA acts as a biological record that can reveal many of the pieces of story that is us.
With 23andMe’s genetic testing services, individuals can see what their DNA says about where in the world their ancestors came from, what populations they might be a part of, and who else in the world shares that DNA with them.
<h6>Types of DNA</h6>
<div style="border: 1px solid gray; padding: 15px; margin-bottom: 10px;">
<table>
<tbody>
<tr>
<td style="text-align: right;">Who contributed this DNA if you are&#8230;</td>
<td style="text-align: center;">Female</td>
<td style="text-align: center;">Male</td>
</tr>
<tr>
<td style="text-align: left; font-size: 13px;">Autosomal DNA is found in the 22 pairs of non-sex chromosomes passed down to us equally from our mothers and fathers, one of each pair from each parent. This is about 96% of the DNA that makes you you.</td>
<td><img loading="lazy" decoding="async" class="aligncenter size-medium wp-image-7188" style="margin: 8px;" title="female_auto" src="https://blog-api.23andme.com/wp-content/uploads/2010/09/female_auto1-300x225.png" alt="" width="200" height="150" /></td>
<td><img loading="lazy" decoding="async" class="size-medium wp-image-7194 aligncenter" style="margin: 8px;" title="male_auto" src="https://blog-api.23andme.com/wp-content/uploads/2010/09/male_auto1-300x225.png" alt="" width="200" height="150" /></td>
</tr>
<tr>
<td style="text-align: left; font-size: 13px;">The X chromosome is one of the larger chromosomes and contains a large number of essential genes. Women have two copies, one each from mother and father; men have just one copy, inherited from their mother (except in rare genetic conditions).</td>
<td><img decoding="async" class="size-medium wp-image-7192 aligncenter" style="margin: 8px;" title="female_x" src="https://blog-api.23andme.com/wp-content/uploads/2010/09/female_x1-300x225.png" alt="" height="150" /></td>
<td><img decoding="async" class="aligncenter size-medium wp-image-7198" style="margin: 8px;" title="male_x" src="https://blog-api.23andme.com/wp-content/uploads/2010/09/male_x1-300x225.png" alt="" height="150" /></td>
</tr>
<tr>
<td style="font-size: 13px;">The Y chromosome is what makes someone male. Men have one of these, passed down from their father.</td>
<td style="text-align: center;">N/A</td>
<td><img decoding="async" class="size-medium wp-image-7200 aligncenter" style="margin: 8px;" title="male_y" src="https://blog-api.23andme.com/wp-content/uploads/2010/09/male_y1-300x225.png" alt="" height="150" /></td>
</tr>
<tr>
<td style="font-size: 13px;">All of us also have mitochondrial DNA (mtDNA), found in the chemical factories &#8212; the mitochondria &#8212; inside each of our cells that convert the food we eat into energy for our bodies. mtDNA is always passed down from mother to child.</td>
<td><img decoding="async" class="size-medium wp-image-7190 aligncenter" style="margin: 8px;" title="female_mt" src="https://blog-api.23andme.com/wp-content/uploads/2010/09/female_mt1-300x225.png" alt="" height="150" /></td>
<td><img decoding="async" class="size-medium wp-image-7196 aligncenter" style="margin: 8px;" title="male_mt" src="https://blog-api.23andme.com/wp-content/uploads/2010/09/male_mt1-300x225.png" alt="" height="150" /></td>
</tr>
</tbody>
</table>
</div>
Each type of DNA has unique properties that are informative for ancestry. Because your mitochondrial DNA comes all in one piece from your mother &#8212; and she received it from her mother, and so on &#8212; we can say pretty definitively where that piece of your DNA came from. In fact, scientists can map all mtDNA onto a family tree of sorts, tracing back to a “mitochondrial Eve”, the common female ancestor that gave rise to all variations of mtDNA around today.
This mapping is possible because DNA isn’t always copied perfectly when it’s passed from parent to child. With each successive generation, the changes spread and become the background from which new changes arise, serving both to distinguish different maternal lineages from each other and to connect lineages to each other at some point in genealogical time. So one thing that 23andMe can tell you is where that piece of DNA &#8212; from your mother’s mother’s mother’s ancestors &#8212; is from. (23andMe customers can see this information in the <a href="https://www.23andme.com/you/haplogroup/maternal/">Maternal Line</a> feature of their account.)
Similarly, because the Y chromosome is passed down exclusively from father to son, we can use it to trace the ancestry of a small part of your DNA if you are male. The same principle of DNA variation spreading and building up through generations allows scientists to construct a tree for all the paternal lineages and allows 23andMe to map a man’s Y chromosome DNA to a particular branch in that tree. (Male 23andMe customers can see this information in the <a href="https://www.23andme.com/you/haplogroup/paternal/">Paternal Line</a> feature of their account.)
<table>
<tbody>
<tr>
<td width="180">
<img loading="lazy" decoding="async" class="alignleft wp-image-7265 size-full" style="margin-top: 15px; margin-right: 10px;" title="dna-pie-labeled" src="http://35.88.189.111/wp-content/uploads/2010/09/dna-pie-labeled.png" alt="" width="151" height="102" />
<img loading="lazy" decoding="async" class="alignleft size-full wp-image-7216" style="margin-right: 10px; margin-top: 10px;" title="ancestry_tree" src="https://blog-api.23andme.com/wp-content/uploads/2010/09/ancestry_tree.png" alt="" width="140" height="105" />
<img loading="lazy" decoding="async" class="alignleft size-full wp-image-7217" style="margin-right: 10px; margin-top: 10px; margin-bottom: 15px;" title="global-origins" src="https://blog-api.23andme.com/wp-content/uploads/2010/09/global-origins.png" alt="" width="140" height="100" />
</td>
<td>Your maternal &#8212; and for some, paternal &#8212; line gives you an interesting piece of your DNA history, but it is a very small part. Your autosomal and X chromosome DNA make up almost 99% of all your DNA, and is passed down from both parents (except for the X chromosome in males, which comes only from the mother). This means that the DNA can be used to infer more distant relatedness between individuals on any branch of their family tree &#8212; 4th cousins, for example, who share common great-great-great-grandparents &#8212; based on the percentage of DNA shared. Thousands of people are already making connections with distant relatives through 23andMe’s database. (23andMe customers can explore our <a href="https://www.23andme.com/you/relfinder/">DNA Relatives</a> (Relative Finder) and  <del>Ancestry Finder</del>  Countries of Ancestry features which use these principles.)
More generally, we can compare your autosomal DNA to that of different populations around the world and show you which groups of people you are most similar to genetically. This can be done at a very high level with broad ethnic groups or global populations, or at a finer-grained level with more specific populations, such as Han Chinese or Norwegian. (23andMe customers can see these using the <del>Ancestry Painting</del>  Ancestry  Composition  <del>Global Similarity</del> and <del>Global Similarity: Advanced</del> <a href="https://www.23andme.com/you/labs/global_similarity_map/">Global Similarity  Map</a>  features.)</td>
</tr>
</tbody>
</table>
Unlike maternal and paternal line analysis, autosomal and X chromosome DNA analysis cannot tell us much definitively past a certain number of generations. Because each pair of chromosomes recombines, or mixes, before being passed down from parent to child, the size of possible shared segments gets successively smaller with each generation. Too small, and it’s no longer possible to tell whether the segment truly came from a shared common ancestor, or if it’s identical simply by chance. The information we can infer, however, is much more versatile. And although scientific methods using autosomal and X chromosome DNA are not as firmly established or plentiful as those used for mtDNA and Y chromosome analyses, this should change as more research accumulates.
The cool part is that all of these features we&#8217;ve just mentioned are just the tip of the iceberg. One thing that separates 23andMe’s services from most other genetic ancestry services is that we use data about hundreds of thousands of variants in the human genome &#8212; places where a single DNA letter can vary between individuals, called single nucleotide polymorphisms, or SNPs (“snips”). This offers greater resolution and versatility than more traditional methods, allowing us to provide a unique and constantly evolving set of tools for exploring your ancestry.
In the <a href="https://blog.23andme.com/2010/09/29/ancestry-at-23andme-introducing-sheridan/">next post in this series</a>, we illustrate 23andMe’s ancestry features in more detail by following some (fictional, but based on real) customers as they explore their 23andMe data.
<h6 style="background-color: #ffc; padding: 10px;">Summary of 23andMe features mentioned in this post:</h6>
<div style="background-color: #ffc; padding: 10px;"><a href="https://www.23andme.com/you/haplogroup/maternal/">Maternal Line</a> &#8211; Uses mitochondrial DNA passed down from your mother to trace the origins of your mother&#8217;s mother&#8217;s mother&#8217;s ancestors.</div>
<div style="background-color: #ffc; padding: 10px;"><a href="https://www.23andme.com/you/haplogroup/paternal/">Paternal Line</a> &#8211; (Possible for men only) Uses Y chromosome DNA passed down to sons from their fathers to trace the origins of their father&#8217;s father&#8217;s father&#8217;s ancestors.</div>
<div style="background-color: #ffc; padding: 10px;"><a href="https://www.23andme.com/you/relfinder/">DNA Relatives</a> (Relative Finder) and  Countries of Ancestry &#8211; Uses autosomal DNA passed down from both parents to connect you to other 23andMe users who may be related to you.</div>
<div style="background-color: #ffc; padding: 10px;">Ancestry Composition  and <a href="https://www.23andme.com/you/labs/global_similarity_map/">Global Similarity Map</a>  &#8211; Uses autosomal DNA passed down from both parents to place your DNA in the broader context of populations, continents, and regions of the world.</div>
<div style="background-color: #eee; padding: 15px; margin-top: 10px; margin-bottom: 10px;">
Other posts in this series:
<a href="https://blog.23andme.com/2010/09/29/ancestry-at-23andme-introducing-sheridan/">Introducing Sheridan</a> &#8211; We meet Sheridan and she learns about her maternal haplogroups.
<a href="https://blog.23andme.com/2010/10/08/ancestry-at-23andme-sheridans-global-origins/">Sheridan&#8217;s Global Origins</a> &#8211; Sheridan compares herself and her friends to various populations around the world.
<a href="https://blog.23andme.com/2010/10/15/ancestry-at-23andme-sheridans-got-relatives/">Sheridan&#8217;s Got Relatives</a> &#8211; Sheridan responds to a fifth cousin and discovers a predicted second cousin in the 23andMe database.
<a href="https://blog.23andme.com/2010/10/22/ancestry-at-23andme-finding-connections/">Finding Connections</a> &#8211; Sheridan and Brian bond over their fourth cousin connection.
<a href="https://blog.23andme.com/2010/10/29/ancestry-at-23andme-old-roots-and-new-horizons/">Old Roots and New Horizons</a> &#8211; Sheridan and Brian put together the pieces to sketch out their shared family tree.
</div>

Ancestry at 23andMe: What Can You Learn?

<img loading="lazy" decoding="async" class="alignright size-full wp-image-6586" title="23andMe_Logo_blog" src="https://blog-api.23andme.com/wp-content/uploads/2010/05/23andMe_Logo_blog.jpg" alt="" width="237" height="236" srcset="https://blogcms.23andme.com/wp-content/uploads/2010/05/23andMe_Logo_blog.jpg 350w, https://blogcms.23andme.com/wp-content/uploads/2010/05/23andMe_Logo_blog-150x150.jpg 150w, https://blogcms.23andme.com/wp-content/uploads/2010/05/23andMe_Logo_blog-300x300.jpg 300w, https://blogcms.23andme.com/wp-content/uploads/2010/05/23andMe_Logo_blog-271x271.jpg 271w" sizes="auto, (max-width: 237px) 100vw, 237px" />
As we have previously detailed here in the Blog, 23andMe received a letter from the Committee on Energy and Commerce of the United States House of Representatives asking for details of our genetic testing services.   We received a second letter from the Committee asking for more information about the incorrect processing of a number of customer samples that we previously discussed in the Blog on June 8, 2010.
If you would like to read the letters 23andMe received from the Committee, they can be accessed as PDFs through the following links:
<ul>
<li>Letter from the Committee on Energy and Commerce of the  United States House of Representatives–May 19, 2010</li>
<li>Letter from the Committee on Energy and Commerce of the  United States House of Representatives–June, 14, 2010</li>
</ul>
23andMe is working to provide Congress with the information they have requested.   Reprinted below is the letter we sent to the Committee on June 28, 2010 in response to their inquiry about the incorrectly processed samples.

June 28, 2010

Hon. Henry A. Waxman, Chairman 
House Committee on Energy and Commerce 
2125 Rayburn House Office Building 
Washington, DC 20515-6115

Hon. Bart Stupak, Chairman 
Subcommittee on Oversight and Investigations 
2125 Rayburn House Office Building 
Washington, DC 20515-6115

Hon. Joe Barton, Ranking Member 
House Committee on Energy and Commerce 
2125 Rayburn House Office Building 
Washington, DC 20515-6115

Hon. Michael C. Burgess, Ranking Member 
Subcommittee on Oversight and Investigations 
2125 Rayburn House Office Building 
Washington, DC 20515-6115


Re: June 14, 2010 letter request to Anne Wojcicki, President, 23andMe, Inc.

Dear Chairman Waxman, Ranking Member Barton, Chairman Stupak and Ranking Member Burgess:

On June 14, 2010, you sent a letter request to Anne Wojcicki, President of 23andMe, Inc. (“23andMe” or “the Company”), seeking information related to a June 8, 2010 announcement by the Company relating to a number of customer DNA samples.   While we are in the process of producing responsive documents, the Company would like to take this opportunity to explain the incident.   At the outset, we understand that a representative of the laboratory processing and analysis company that 23andMe uses will meet with you this week and will certainly be in the best position to discuss the issues that occurred within their facility.   Our description of events at the laboratory is limited to 23andMe’s own understanding of what happened there.

I.   How 23andMe’s Collection of Customer DNA Samples and NGI’s Processing and Analysis Operate

Preliminarily, we thought it would help to provide a step-by-step explanation of how 23andMe operates with respect to the collection of customer DNA samples and their processing and analysis by the Company’s third-party laboratory vendor, the National Genetics Institute (“NGI”) a wholly owned subsidiary of the Laboratory Corporation of America.

First, customers visit the 23andMe website and purchase one of three products for personalized genetic testing.   23andMe then sends to each customer a kit to collect a DNA sample, including a vial for saliva marked with a unique barcode, from which customer DNA will be extracted and analyzed by NGI.   The customer deposits a sample of saliva in the vial and then sends it directly to NGI.   The Company uses the unique barcode on each saliva collection vial to track and distinguish each customer’s unique data while maintaining customer privacy.

NGI is a Clinical Laboratory Improvement Amendments Program-certified laboratory that

provides advanced clinical genetics testing services for blood screening, medical testing, and clinical research.   Licensed as a clinical laboratory provider by both state and federal agencies, NGI participates in a number of approved quality control programs, and holds active Biologics Licenses from the U.S. Food and Drug Administration for screening of plasma for blood borne infectious agents.   It also provides advanced genetic testing services to physicians, hospitals, and clinics and has supported numerous pharmaceutical and biotechnology companies in the clinical development of new infectious disease and oncology therapies.   (see http://www.ngi.com/services/index.asp).   We understand NGI complies with strict professional, regulatory, and corporate quality-assurance standards.   23andMe employees and consultants do not participate in the processing and analysis of data at NGI, although we rely on the data returned.


Upon receipt of the saliva samples, NGI logs them by their assigned bar codes into NGI’s system, and then processes them through “amplification,” extracting the customers’ DNA from their saliva samples.   Each customer’s DNA is then placed by pipette into an assigned slot contained on a well plate.   The well plates used by NGI for testing of 23andMe customer samples are 5”x7”, and contain 96 slots to allow for the processing of up to 96 customer DNA samples per plate.   These well plates are then inserted into Illumina-platform equipment for analysis of nearly 600,000 data points that 23andMe provides to its customers.

After NGI completes the analysis, the collected data for each sample is linked to its accompanying bar code, and NGI electronically sends the data encrypted to 23andMe through a secure FTP site.   A single electronic file contains the data from one well plate.   Upon receiving this data, 23andMe matches each barcode to the customer it belongs to, and then uploads the data from each barcode to the customer’s individual account.   Finally, 23andMe sends emails to its customers notifying them that their data are loaded and ready for viewing.

II.   Factual Background of the June 2010 Incident

Summary

In brief, the June 2010 incident was caused by the human error of one of NGI’s certified technicians accidentally and wrongly inverting one well plate, which contained 96 customer DNA samples, nine of which failed processing by 180 degrees.   This led to the Company’s receipt of incorrect results, which were then transmitted to customers.   However, 23andMe responded rapidly to the problem, advised consumers of the problem, removed the inaccurate results in less than 24 hours, and provided those impacted with their correct results within six (6) days.   While 23andMe takes the incident seriously, the Company rapidly resolved it.   Since the incident, both 23andMe and NGI have further strengthened their quality control systems to avoid any further such problems.

Detailed Account 

The aforementioned inversion of the well plate by 180 degrees caused NGI’s computer to assign DNA information to incorrect barcodes, as the slots were assigned to barcodes in the computer before plate insertion.   I note that the plate inversion could have happened in any such lab for any such tests coming from any hospital, doctor’s office, or other NGI client — it was not a problem uniquely related to 23andMe samples.   Unfortunately, NGI did not detect the error before it transmitted the erroneous electronic data file from the inverted plate to 23andMe.   The Company received the NGI-generated, faulty data and uploaded it to each customer’s individual account and emailed those customers that their data was available.   Customers received these emails between 6 and 9 p.m. on the evening of June 1.

Early in the morning of June 2, 23andMe’s Director of Engineering, Alex Khomenko, checked his email and was alerted that several 23andMe customers had apparently received inaccurate genetic reports.   For example, in at least one instance, a customer had received genetic data indicating that the customer was the wrong sex.   That same morning, Mr. Khomenko contacted the Company’s Customer Service Manager, Michelle Klucsor, who said she had received similar customer complaints via email.

To identify what happened, Mr. Khomenko ran a program covering 100% of the samples received from NGI on June 1.   This program provided the names (which the customers provided when signing up with 23andMe) and sex (which the lab identified in its DNA analysis) of these customers.   He then compared a customer’s name against the lab-identified sex of the customer.   He noticed that, in some instances, the gender of a customer’s name (for example, “Sarah”) did not match the sex (for example, “male”) contained in the lab report.   He compiled a list of all such inconsistencies.   Mr. Khomenko then reviewed the original electronic files sent from NGI on June 1, 2010 and determined that all of the inconsistencies stemmed from a single electronic file, and, thus, he concluded, from one well plate.

As Mr. Khomenko conducted his investigation, 23andMe alerted NGI of the error.   NGI also conducted its own investigation.   Around 1 pm on June 2, 2010, 23andMe concluded that the data from the single file containing 87 customer data sets contained inaccuracies and began the process of removing this data from the accompanying accounts.   During this period, 23andMe continued discussions with NGI.   At approximately 4 pm on June 2, 2010 — less than 24 hours after customers had received the incorrect data &#8212; 23andMe deleted the erroneous data from the affected customers’ databases and sent emails to each affected customer alerting them of the error.

On June 5, NGI confirmed that its investigation had concluded that the issue stemmed from an error on a single well plate.   NGI’s investigation showed that the well plate had been inverted, causing the inaccurate customer data.   NGI had reprocessed the data of all impacted customers while its investigation was ongoing.   NGI re-ran the entire plate from both the amplified DNA samples and the original saliva samples provided by the customers.   In doing so, NGI was able to confirm the accuracy of the updated data.   23andMe was able to upload correct reports into the affected customers’ accounts on June 8, 2010.

III. Steps Taken by 23andMe and NGI to Ensure No Future Errors

Since this incident, NGI has informed 23andMe that NGI has taken steps to help ensure that such errors do not recur.   Specifically, 23andMe understands that NGI has modified the physical shape of its well plates to prevent them from being inverted in the machine that conducts the analysis.   Attached please find a photograph of the old well plate and one of the newly-designed well plates that are now in use.

For its part, 23andMe has implemented improved quality-control procedures to double-check the accuracy of NGI’s returned lab results before providing them to customers.   For the period of June 8 through June 23, 23andMe cross-referenced a customer’s name (which 23andMe predicts to be either male or female based on traditional name use) with the customer’s sex information pulled from lab data.   Doing so allowed 23andMe to identify potential errors, where the gender of a customer’s name is inconsistent with lab-identified sex data for that customer.

Starting June 24, 23andMe implemented a similar quality check with additional data.   As of June 10, 2010, 23andMe has been collecting customer date of birth and sex information pursuant to requirements that NGI is following.   23andMe’s new process cross-references this customer-provided sex data with that generated by the lab data.   Potential errors will be flagged where there are inconsistencies.

We look forward to speaking with you further about this issue.   If you have any questions in the meantime, please call me at (202) 339-8523.


Sincerely,



Michael J. Madigan 
Joshua P. Galper 
Stephanie Maya Cowles

Update on 23andMe and Committee on Energy and Commerce of the United States House of Representatives

The tenth anniversary of the completion of the first draft of the human genome is approaching, apparently putting a lot of scientists in the mood for reflection on the past and speculation about the future of genetics.
The journal Nature has a series of opinion articles and two news articles on the subject. &nbsp; All are available online free of charge. &nbsp; There are also other human genome related materials available at <a href="https://www.nature.com/news/specials/humangenome/index.html#editorial" target="_blank" rel="noopener noreferrer">The Human Genome at Ten</a>.
<img loading="lazy" decoding="async" class="alignright size-full wp-image-6314" title="81-72" src="https://blog-api.23andme.com/wp-content/uploads/2010/04/81-72.jpg" alt="" width="377" height="282" srcset="https://blogcms.23andme.com/wp-content/uploads/2010/04/81-72.jpg 500w, https://blogcms.23andme.com/wp-content/uploads/2010/04/81-72-300x225.jpg 300w" sizes="auto, (max-width: 377px) 100vw, 377px" />Researchers working at an NHGRI-supported large-scale sequencing center./The Broad Institute of MIT and Harvard/NHGRI multimedia gallery
<ul>
<li><a href="https://www.nature.com/nature/journal/v464/n7289/full/464674a.html" target="_blank" rel="noopener noreferrer">Has the revolution arrived? — Francis Collins</a></li>
<li><a href="https://www.nature.com/nature/journal/v464/n7289/full/464676a.html" target="_blank" rel="noopener noreferrer">Multiple personal genomes await — J. Craig Venter</a></li>
<li><a href="https://www.nature.com/nature/journal/v464/n7289/full/464678a.html" target="_blank" rel="noopener noreferrer">Point: Hypotheses First &#8211; Robert Weinberg</a></li>
<li><a href="https://www.nature.com/nature/journal/v464/n7289/full/464679a.html" target="_blank" rel="noopener noreferrer">Counterpoint: Data first &#8211; Todd Golub</a></li>
<li><a href="https://www.nature.com/news/2010/100331/full/464664a.html" target="_blank" rel="noopener noreferrer">Life is complicated — Erika Check Hayden</a></li>
<li><a href="https://www.nature.com/news/2010/100331/full/464668a.html" target="_blank" rel="noopener noreferrer">The human race — Alison Abbott</a></li>
</ul>
The British Medical Journal features a debate between two scientists over whether modern genetics is &#8220;blind alley.&#8221; &nbsp; These articles are also available free of charge.
<ul>
<li><a href="http://www.bmj.com/cgi/content/full/340/mar30_2/c1156?maxtoshow=&amp;hits=10&amp;RESULTFORMAT=&amp;fulltext=blind+alley&amp;searchid=1&amp;FIRSTINDEX=0&amp;sortspec=date&amp;resourcetype=HWCIT" target="_blank" rel="noopener noreferrer">Is modern genetics a blind alley? Yes — James Le Fanu</a></li>
<li><a href="http://www.bmj.com/cgi/content/full/340/mar30_2/c1088?maxtoshow=&amp;hits=10&amp;RESULTFORMAT=&amp;fulltext=blind+alley&amp;searchid=1&amp;FIRSTINDEX=0&amp;sortspec=date&amp;resourcetype=HWCIT" target="_blank" rel="noopener noreferrer">Is modern genetics a blind alley? No — D J Weatherall</a></li>
</ul>
It&#8217;s not just the anniversary of the draft sequence that looms. &nbsp; DNA Day, which was created in 2003 by a congressional resolution to celebrate the completion of the Human Genome Project and the 50th anniversary of the description of the double-helix structure of DNA by James D. Watson and Francis H.C. Crick, is coming up on April 25th. &nbsp; To accommodate classroom schedules, many events will be taking place on Friday, April 23rd.
We&#8217;ll be rounding up a listing of DNA Day activities in the coming week or so, but you can start your preparations by checking our listing of fun DNA activities.

Genetics: Looking Back and Looking Forward

Human Prehistory 101:  Out of (Eastern) Africa

<img loading="lazy" decoding="async" class="alignright size-full wp-image-4632" title="iStock_000001256085XSmall" src="https://blog-api.23andme.com/wp-content/uploads/2009/09/iStock_000001256085XSmall.jpg" alt="iStock_000001256085XSmall" width="300" height="199" />
About 10,000 years ago, the prehistoric hunter-gatherers of Europe began meeting some new neighbors.
These farmers spread gradually at first, expanding from the Near East through Anatolia and the Balkans. Then agriculture exploded, reaching present-day Britain within a few thousand years. The farmers settled into houses, which soon evolved into villages, towns and eventually cities.
The archaeological record tells us that much. But what it doesn&#8217;t reveal is how agriculture spread. Did it spread like a fad, as hunter-gatherer groups saw what their neighbors were doing and imitated their ways? Or was it more of an invasion, with subsequent generations of farmers advancing across the continent and overwhelming indigenous hunter-gatherer populations as they went?
Some genetic studies suggest the former. But in the September 3 issue of <a id="rbdr" title="Science" href="http://www.sciencemag.org/cgi/content/abstract/1176869" target="_blank" rel="noopener">Science</a>, the first study to directly compare ancient DNA (aDNA) from prehistoric burials of hunter-gatherers to that their agricultural neighbors suggests migrants spread farming through Europe.
The research team, led by Barbara Bramanti of Mainz University, sequenced the mitochondrial DNA (mtDNA) of just under 50 individuals unearthed from various prehistoric burial sites across central and eastern Europe. Half the individuals came from hunter-gatherer societies, and the other half from communities based around farming. As a comparison, they also sequenced the mtDNA of nearly 500 modern Europeans from the same parts of Europe.
The authors&#8217; first task was to compare the hunter-gatherer mtDNA to that of the farmers. Upon doing so, they found both groups to be so different from each other that there is no way the two could be closely related. There was absolutely no overlap in the kinds of mtDNA lineages &#8211; known as haplogroups &#8211; between the hunter-gatherers and the farmers. This stark difference suggests the earliest farmers were not related to the hunter-gatherers, and most likely came to the region by migration.
And how do these two groups compare to the modern-day Europeans? The hunter-gatherers had little in common with modern people. Haplogroup U, the most common lineage among the hunter-gatherers, is one of the least common haplogroups among modern Europeans.
But the authors also found little to connect the farmers to modern Europeans. Other studies have pointed to a substantial genetic component from the Near East among Europeans, but the authors found many genetic differences between the two groups.
Based on these results, the authors have proposed an alternative theory. The unexplained component to the genetic make-up of modern Europeans may be explained by later migrations that post-date the skeletal remains examined here. It could have been a later expansion of farmers from the Near East, or perhaps an influx of hunter-gatherers from the west. The exact details remain unclear, but the authors are confident that, with additional DNA analysis, they can hope to unravel the increasingly complex story of the peopling of Europe.

23andMe and You — Page 10