As the series <a href="https://www.pbs.org/wnet/finding-your-roots/" target="_blank" rel="noopener noreferrer">Finding Your Roots with Henry Louis Gates, Jr.</a> begins its 10-week run on PBS, The Blog will feature posts from 23andMe’s Ancestry Ambassadors featuring their own stories about using DNA to dig into ancestry.
By Andrea Badger
<img loading="lazy" decoding="async" class="alignright size-medium wp-image-12315" title="Andrea's Tree" src="https://blog-api.23andme.com/wp-content/uploads/2012/04/Andreas-Tree-226x300.jpg" alt="" width="226" height="300" srcset="https://blogcms.23andme.com/wp-content/uploads/2012/04/Andreas-Tree-226x300.jpg 226w, https://blogcms.23andme.com/wp-content/uploads/2012/04/Andreas-Tree.jpg 442w" sizes="auto, (max-width: 226px) 100vw, 226px" />
There has been a legend in my family, passed down from generation to generation, about my third great-grandfather Nathaniel Lewis. According to family folklore, his name wasn’t originally Nathaniel Lewis, but rather, Nathaniel Levi. As the story goes, our Lewis ancestors were Jewish people who converted to Christianity and changed their name from Levi to Lewis.
I had always wondered if this family story was really true. Everyone in our family has been told this legend but no one really had any conclusive evidence — just small clues. My grandmother and her siblings remember their mother singing Jewish songs to them as children. We also have an old newspaper article about our ancestor that states in passing ‘Nathaniel Lewis has lived in Scotland for many years but has no Scot’s blood’. Many of my relatives have speculated that this statement reveals that although Nathaniel was of Scottish nationality, he had a different ancestral background — Ashkenazi Jewish. However, conclusive evidence about this hypothesis was lacking until I joined 23andMe.

<img loading="lazy" decoding="async" class="alignright size-medium wp-image-12316" title="Andrea's Community Response" src="https://blog-api.23andme.com/wp-content/uploads/2012/04/Andreas-Community-Response-300x249.jpg" alt="" width="300" height="249" srcset="https://blogcms.23andme.com/wp-content/uploads/2012/04/Andreas-Community-Response-300x249.jpg 300w, https://blogcms.23andme.com/wp-content/uploads/2012/04/Andreas-Community-Response.jpg 368w" sizes="auto, (max-width: 300px) 100vw, 300px" />
When I first joined 23andMe in 2009, Relative Finder was just being introduced and the Ancestry Finder feature did not yet exist. As I corresponded with my Relative Finder matches, I noticed that many of my potential relatives said that they were of Ashkenazi Jewish descent. I wondered if this high number of Jewish Relative Finder matches was typical for someone with Northern European ancestry, so I turned to the 23andMe community for help and posted my questions on the community forums. I communicated with fellow 23andMe users and quickly realized that my genetic profile wasn’t typical for someone without any Jewish background. Instead, my DNA confirmed the old family story and indicated that it was highly likely that I do have Jewish ancestry.
<img loading="lazy" decoding="async" class="alignright size-medium wp-image-12318" title="Andrea's GAunt and Uncle Ancestry Finder" src="https://blog-api.23andme.com/wp-content/uploads/2012/04/Andreas-GAunt-and-Uncle-Ancestry-Finder-300x164.jpg" alt="" width="300" height="164" srcset="https://blogcms.23andme.com/wp-content/uploads/2012/04/Andreas-GAunt-and-Uncle-Ancestry-Finder-300x164.jpg 300w, https://blogcms.23andme.com/wp-content/uploads/2012/04/Andreas-GAunt-and-Uncle-Ancestry-Finder-271x149.jpg 271w, https://blogcms.23andme.com/wp-content/uploads/2012/04/Andreas-GAunt-and-Uncle-Ancestry-Finder-372x204.jpg 372w, https://blogcms.23andme.com/wp-content/uploads/2012/04/Andreas-GAunt-and-Uncle-Ancestry-Finder.jpg 469w" sizes="auto, (max-width: 300px) 100vw, 300px" />Here is my Ancestry Finder, with the settings focusing on the Ashkenazi Jewish segments. The blue spots are regions where a 23andMe customer shares a segment of DNA with me AND has stated that he or she has Jewish ancestors.
I decided to get my great-aunt &amp; great-uncle from that side of the family tested to see if they also had <a href="https://blog.23andme.com/articles/ashkenazi-ancestry-and-health">evidence of Ashkenazi Jewish</a> admixture. Around this time, Ancestry Finder, which has a specific section dedicated to Jewish ancestry, was introduced. This feature was also beneficial in my quest.
As I expected, my great-aunt &amp; great-uncle also showed significant Jewish ancestry — more than I have, because they are two generations closer to our Jewish ancestor than I am.
Thanks to DNA testing, we have clear evidence of a Jewish ancestor in our past for the first time. Without 23andMe, I might never have known if there was any truth to this family legend. Why did the Lewis family feel the need to convert from Judaism to Christianity and change their name? I am actively searching to uncover this information, but much of Nathaniel Lewis’s life story has likely been lost to history. However, his DNA lives on in his descendants and provides clues about his background. Often, when traditional genealogy methods fail, you can turn to DNA to uncover more about your ancestral heritage. You never know what sort of surprises can be uncovered!
<img loading="lazy" decoding="async" class="alignright size-thumbnail wp-image-12325" title="andrea 23andMe pic" src="https://blog-api.23andme.com/wp-content/uploads/2012/04/andrea-23andMe-pic-150x150.jpg" alt="" width="150" height="150" srcset="https://blogcms.23andme.com/wp-content/uploads/2012/04/andrea-23andMe-pic-150x150.jpg 150w, https://blogcms.23andme.com/wp-content/uploads/2012/04/andrea-23andMe-pic-271x271.jpg 271w, https://blogcms.23andme.com/wp-content/uploads/2012/04/andrea-23andMe-pic-372x372.jpg 372w" sizes="auto, (max-width: 150px) 100vw, 150px" />
When she is not performing genetic comparisons on Family Inheritance Advanced or answering questions on the 23andMe community forums, Andrea Badger attends college at the University of Washington and will be receiving two bachelor’s degrees in June of this year. She writes the genetic genealogy blog at www.andreasancestors.com.

23andMe Blog

23andMe Blog Team

Finding a Family’s Jewish Ancestry

This month, 23andMe published a new article in PLoS One entitled “<a href="http://www.plosone.org/article/info:doi%2F10.1371%2Fjournal.pone.0034267">Cryptic Distant Relatives are Common in both Isolated and Cosmopolitan Samples</a>.&#8221; Authored by former 23andMe scientists, Brenna Henn and Lawrence Hon, along with current 23andMe scientists and 23andMe advisor, Itsik Pe’er, of Columbia University, the article describes the nuts and bolts of the method behind our innovative Relative Finder tool. In this post, Brenna discusses what the findings mean for our notion of “relatives” and explores the many special features of the 23andMe customer database.
By Brenna Henn
You probably know how many siblings you have or the number of first cousins. But do you know how many 2nd cousins you have? Does 38 sound reasonable? What about the number of 3rd, 4th, or 5th cousins?
The answer may surprise you.
<h6>What&#8217;s a Fourth Cousin?</h6>
Under a simple model where a family has 2-3 children, you would have 190 third cousins, 940 fourth cousins, and a whopping 4,700 fifth cousins.
Going back to 8th cousins (or 9 generations back to a common ancestor), the model we developed predicts you would have over half a million 8th cousins!
<iframe loading="lazy" src="https://www.youtube.com/embed/qG6BFjoXHvY" width="560" height="315" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
Now, this model is a simplification because some families have a dozen children and some have none; but this model does help illustrate just how many potential distant cousins are out there.
<h6>Relative Finder Tool</h6>
Finding a relative in the 23andMe database, however, rests on two other important conditions. First, the relative has to be a 23andMe customer. Second, you and the relative need to share a long identical segment of DNA. The more distant a pair of cousins, the less identical DNA they share. Very small fragments of DNA can be hard to detect with our algorithm.
So although you might have thousands of 6th cousins, we think we can only detect about 4% of them with 23andMe’s current technology.
Our detection success is much higher for more closely related cousins, though — we can detect about 46% of 4th cousin pairs and 90% of 3rd cousin pairs.
<h6>Connections Among Those with Ashkenazi Ancestry</h6>
Our ability to detect a person’s distant cousins is also influenced by the ancestry of the individual. If you are Ashkenazi Jewish, you may have noticed that 23andMe’s Relative Finder feature shows you over a thousand cousins.
This is because Ashkenazi Jews are more closely related to each other than a random sample of European-Americans. Over the past several hundred years, a cultural tendency to choose marriage partners of the same ethnicity (also known as endogamy) means that Ashkenazi individuals are more likely to share the same ancestors.
In fact, we estimate that any two randomly chosen individuals who identify as Ashkenazi is on average the genomic equivalent of 4th-5th cousins because they share many recent common ancestors.
This phenomenon doesn’t just occur in the Ashkenazim.
<h6>Looking at Different Populations</h6>
We looked at 121 populations, many from the 23andMe customer database. Pairs of individuals in Iceland, Finland, or South Africa are more closely related than pairs of individuals from Italy or Japan.
<div style="float: right; text-align: left; width: 200px; padding: 10px; margin-left: 15px; border: 1px solid black;"><img loading="lazy" decoding="async" class="alignright size-full wp-image-12163" style="float: left; margin-right: 5px;" title="small_23andMe_logo" src="https://blog-api.23andme.com/wp-content/uploads/2012/04/JRBgdIBXKIeVIdETJrxYIw_ttam_logo.jpg" alt="" width="24" height="40" />Connect with 23andMe members who share DNA and ancestors. Not yet a 23andMe customer? <a href="https://www.23andme.com/store">Visit our store</a> or <a href="https://www.23andme.com">learn more</a>!</div>
In our analyses, we also looked at DNA data for over 5,000 individuals with just European ancestry in the 23andMe database. The DNA indicated that in this sample there are over 5,000 3rd cousin pairs and 30,000 4th cousin pairs. This result is important beyond thinking about genealogy.
It means that large disease association studies that sample thousands of individuals will have many pairs of distant cousins in the dataset. By identifying cryptic (or non-obvious) relatives in databases, researchers can see if certain disease mutations occur more often in different extended families.

Brenna Henn

The method behind the Relative Finder tool

As the series <a href="https://www.pbs.org/wnet/finding-your-roots/" target="_blank" rel="noopener noreferrer">Finding Your Roots with Henry Louis Gates, Jr.</a> continues its 10-week run on PBS, The Blog will feature posts from 23andMe’s Ancestry Ambassadors featuring their own stories about using DNA to dig into ancestry.
By Shannon Christmas
<img loading="lazy" decoding="async" class="alignright size-full wp-image-12107" title="shannon's gp" src="https://blog-api.23andme.com/wp-content/uploads/2012/04/shannons-gp.jpg" alt="" width="220" height="278" />
African American genealogy remains a challenging jigsaw puzzle where half of the pieces seem irrevocably lost. Many families scarred by chattel slavery buried their pasts to distance themselves and their progeny from the horrors of bondage.
<h2>A Fractured History</h2>
Now, advances in genetics and Internet technology have unearthed some of the long-buried pieces of our significantly fractured history.
Uncovering some of those missing pieces for my family required an open mind. One of my paternal great-grandmothers, Katie Lee Davis of Warren County, North Carolina, inherited a revisionist version of our family’s past.
In her correspondence with one of my cousins, Grandma Katie identified her ancestors, wrote lovingly of her paternal aunts, and recalled never having known a former slave among her relatives. Yet in 2010, 16 years after her death, revelations about Grandma Katie’s ancestors began to tell a different story. 

<img loading="lazy" decoding="async" class="alignright size-medium wp-image-12109" title="gravestone" src="https://blog-api.23andme.com/wp-content/uploads/2012/04/gravestone-300x225.jpg" alt="" width="300" height="225" srcset="https://blogcms.23andme.com/wp-content/uploads/2012/04/gravestone-300x225.jpg 300w, https://blogcms.23andme.com/wp-content/uploads/2012/04/gravestone.jpg 453w" sizes="auto, (max-width: 300px) 100vw, 300px" />
Marriage and death records from Warren County list Grandma Katie’s paternal grandparents as Henry and Lucinda Davis, an African-American couple about whom little else is known.
<h2>A Pedigree</h2>
However, in the summer of 2010, Ray, the husband of one of my father’s first cousins, emailed me a pedigree outline that omitted Henry’s name and replaced it with a Peter “White” Davis. The glaring conflict between the government documents I had examined and this new email raised questions.
Who was Peter “White” Davis? Was he really Grandma Katie’s grandfather?
The answers to those questions only heightened my curiosity. Ray reported that Peter “White” Davis, a slave owner formally named Peter Randolph Davis, allegedly sired many mulatto children with his slaves. According to one of Katie’s elderly distant relatives, Grandma Katie’s father, Richard D. Davis, was one of those mulatto children.
<img loading="lazy" decoding="async" class="alignright size-medium wp-image-12108" title="erasmuschristmas" src="https://blog-api.23andme.com/wp-content/uploads/2012/04/erasmuschristmas-222x300.jpg" alt="" width="222" height="300" srcset="https://blogcms.23andme.com/wp-content/uploads/2012/04/erasmuschristmas-222x300.jpg 222w, https://blogcms.23andme.com/wp-content/uploads/2012/04/erasmuschristmas.jpg 225w" sizes="auto, (max-width: 222px) 100vw, 222px" />
Tracing Peter Randolph Davis’ lineage yielded another discovery. Peter’s maternal great-grandparents included a couple I had encountered in previous research: Captain William Green and Mary Elizabeth Christmas. Captain Green and his wife, Mary, were indirect ancestors of my great-grandfather, Richard Christmas.
<h2>A Warren County Planter</h2>
Richard Christmas’s paternal grandfather, Lewis Yancey Christmas, a wealthy Warren County planter and attorney, took two slaves as common-law wives. The first union produced 12 children, including my great-great-grandfather, Erasmus Christmas.
If the Peter Randolph Davis story was accurate, then my great grandfather Richard Christmas and my great grandmother Katie Lee Davis were not only husband and wife for 60 years, but 4th cousins once removed.
The possibility of a consanguineous marriage, though initially unsettling, provided an opportunity to verify this new paternity claim using DNA testing. Web-based DNA analysis tools allow one to search an individual’s raw DNA data file from 23andMe for runs of homozygosity and DNA segments indicating one’s parents shared recent common ancestors.
<h2>Cousin Test</h2>
Since my grandfather, the son of Richard Christmas and Katie Lee Davis had tested with 23andMe, the truth sat just a few keystrokes away. GEDMatch.com’s “Cousin Test for Parents” identified nine runs of homozygosity among my grandfather’s 22 autosomal chromosomes, amounting to more than 55 centimorgans (cM) of DNA, an amount that suggests his parents were at least 4th cousins.
A similar tool created by mathematician David Pike (<a href="http://www.math.mun.ca/%7Edapike/FF23utils/roh.php">http://www.math.mun.ca/~dapike/FF23utils/roh.php</a>) replicated the results. Richard Christmas and Katie Lee Davis shared a bloodline, proving that Peter Randolph Davis was Katie’s paternal grandfather.
<img loading="lazy" decoding="async" class="alignright wp-image-12111 size-medium" title="shannondoc" src="http://35.88.189.111/wp-content/uploads/2012/04/shannondoc-218x300.jpg" alt="" width="218" height="300" srcset="https://blogcms.23andme.com/wp-content/uploads/2012/04/shannondoc-218x300.jpg 218w, https://blogcms.23andme.com/wp-content/uploads/2012/04/shannondoc.jpg 473w" sizes="auto, (max-width: 218px) 100vw, 218px" />
In early 2012, I obtained a slave inventory from an estate file for Dr. Stephen Davis (Peter Randolph Davis’ father); the family of Henry and Lucinda Davis appears among the slaves listed.
Like so many former slaves, the paternal relatives with whom my great-grandmother spent her earliest years clearly sought to conceal their dark history to embrace a brighter future. But DNA illuminated how that past proved prologue.
23andMe provides genetic testing services for informational purposes; your results may or may not help you find or identify relatives or family members.
When not updating pedigree charts or mapping his chromosomes, Shannon Christmas is the founder and Chief Market Advisor/Design Strategist of The Christmas Collective, a strategic real estate and land use consulting atelier.

Shannon Christmas

The Missing Pieces in an African American Family History

As the series <a href="https://www.pbs.org/wnet/finding-your-roots/" target="_blank" rel="noopener noreferrer">Finding Your Roots with Henry Louis Gates, Jr.</a> begins its 10-week run on PBS, The Blog will feature posts from 23andMe’s <a href="../2012/01/22/new-23andme-ancestry-ambassadors-group/">Ancestry Ambassadors</a> featuring their own stories about using DNA to dig into ancestry.
By Tim Janzen, M.D.
My father, Robert Janzen, comes from a long line of hardworking Low German Mennonite farmers. But when 23andMe developed the feature to identify <a href="https://blog.23andme.com/articles/detail-for-ashkenazi-ancestry">Ashkenazi Jewish</a> heritage, I really wanted to determine whether his data suggested any Jewish ancestry. Let me explain.
His Mennonite ancestors were persecuted in the Low Countries – in what is now the Netherlands and Belgium – and in the 1500s they fled to a safer haven in what is now Poland.   After Catherine the Great opened Russia to settlers, his ancestors migrated to South Russia between 1789 and 1819 where they established small villages of Mennonites on the Russian Steppe.   After many
After Catherine the Great opened Russia to settlers, his ancestors migrated to South Russia between 1789 and 1819 where they established small villages of Mennonites on the Russian Steppe.   After many hardships they eventually prospered and developed thriving agricultural colonies that helped transform South Russia into the “breadbasket” of the world before about a third of the Mennonites immigrated to the United States in the 1870s.
The Mennonites who lived in Poland and Russia were an endogamous religious group, meaning they rarely married others who were not adherents to their faith. But there were
<img loading="lazy" decoding="async" class="aligncenter wp-image-11779 size-full" src="http://35.88.189.111/wp-content/uploads/2012/03/Jacob-Peters-and-Helena-Bergman.jpg" alt="" width="221" height="319" srcset="https://blogcms.23andme.com/wp-content/uploads/2012/03/Jacob-Peters-and-Helena-Bergman.jpg 221w, https://blogcms.23andme.com/wp-content/uploads/2012/03/Jacob-Peters-and-Helena-Bergman-208x300.jpg 208w" sizes="auto, (max-width: 221px) 100vw, 221px" />
many exceptions to that practice, and over the centuries a significant number of non-Mennonites joined the Mennonite faith.   Relatives on my father’s mother’s side have said that one of our ancestors was Jewish. My father&#8217;s great uncle Johann Peters conveyed that we descend from a Catholic priest who married a “redheaded Jewess” sometime in the distant past. Who this was we do not know.
According to the historical record between 1750 and 1790 26,000 Jewish followers of Jacob Frank converted to Christianity in Poland. Perhaps my Jewish ancestor was among them. Traditional genealogical tools and family stories helped to identify some possibilities. There was Joseph Nowitzky (1776-1844), whose ancestry is cloaked in mystery.
The Nowitzky name is found among Ashkenazi Jews, and family stories from relatives in Canada said that Joseph Nowitzky was a traveling Jewish salesman whose daughter Maria Nowitzky lived with a Mennonite family and eventually married a son from that family.   But written records from South Russia suggest that Joseph Nowitzky had become a Mennonite by 1801.   He and his family are listed in the major Mennonite censuses from 1801 to 1816. Another relative has heard that we are descended from a woman of Jewish background named Justina von Liechtenstein. So I was faced with a problem many genealogists confront – an end to the paper trail and conflicting family stories. This is where using DNA can help. While any two people’s genomes are 99.5 percent identical, that small bit of difference is incredibly important. It’s what makes each of us unique and it allows genetic genealogists to find relatives and map out information about our ancestry. Fundamentally this comes down to making comparisons, either between individuals to see how closely they are related, or comparing an individual to groups of individuals to determine common ancestry.
The closer two people are related, the more similar their DNA. The more shared ancestry a person has with a group, the more segments of DNA he or she shares with that group of people. 23andMe compares individuals in their database with its Relative Finder tool and finds potential matches. Using an advanced tool called “Ancestry Finder,” you combine Relative Finder matches with ancestry survey information about the country of origin of their grandparents. This can help tell you more about your ancestry.
You can also tweak the controls and increase or decrease the length of the matching segments, measured in a unit called centimorgans (cMs). When I set the minimum segment size to five cMs, set the number of grandparents from the same country to one and clicked the box to show Ashkenazi Jewish ancestry, Ancestry Finder indicated that between 2 percent and 3.8 percent of my father’s DNA is of Ashkenazi Jewish origin.
Results for my father&#8217;s sisters are similar and the average amount of DNA that is of <a href="https://blog.23andme.com/articles/detail-for-ashkenazi-ancestry">Ashkenazi Jewish</a> origin for my father and his four sisters is 2.27 percent.
<img loading="lazy" decoding="async" class="aligncenter wp-image-11785 size-full" title="Ancestry Finder Display" src="http://35.88.189.111/wp-content/uploads/2012/03/Ancestry-Finder-Display.jpg" alt="" width="468" height="362" srcset="https://blogcms.23andme.com/wp-content/uploads/2012/03/Ancestry-Finder-Display.jpg 468w, https://blogcms.23andme.com/wp-content/uploads/2012/03/Ancestry-Finder-Display-300x232.jpg 300w" sizes="auto, (max-width: 468px) 100vw, 468px" />
I also have data from two distant relatives who descend from my father’s great-great-grandparents, Jacob Peters (b. 1823) and Helena Bergmann (b. 1826).   Helena Bergmann’s mother was Justina Nowitzky, who was a daughter of Joseph Nowitzky.   The Ancestry Finder results indicate that my father’s relatives have an average of 4.35% Ashkenazi Jewish ancestry.   This would be consistent with each of them being approximately 1/32 Ashkenazi Jewish in origin.   The Ancestry Finder results for my father and his sisters would suggest that they are about 1/64 Ashkenazi Jewish in origin. I reviewed the 23andMe results of 33 other Mennonites, as well as the data from my father’s paternal cousins to see if they show any evidence of Ashkenazi Jewish ancestry.   None of them show more than 1 percent Ashkenazi Jewish ancestry.   These results confirm that my father indeed has Ashkenazi Jewish ancestry on his mother&#8217;s side.   I cannot prove at this time that the Ashkenazi Jewish ancestry came through Joseph Nowitzky, but that is a strong possibility.   If the Jewish ancestry wasn’t from Joseph Nowitzky then it could have come from one or more of Jacob Peters’ and Helena Bergmann’s great-grandparents. In any
The Ancestry Finder results for my father and his sisters would suggest that they are about 1/64 Ashkenazi Jewish in origin. I reviewed the 23andMe results of 33 other Mennonites, as well as the data from my father’s paternal cousins to see if they show any evidence of Ashkenazi Jewish ancestry.   None of them show more than 1 percent Ashkenazi Jewish ancestry.   These results confirm that my father indeed has Ashkenazi Jewish ancestry on his mother&#8217;s side.   I cannot prove at this time that the Ashkenazi Jewish ancestry came through Joseph Nowitzky, but that is a strong possibility.   If the Jewish ancestry wasn’t from Joseph Nowitzky then it could have come from one or more of Jacob Peters’ and Helena Bergmann’s great-grandparents. In any case the Ancestry Finder results from 23andMe confirm that my father does have Jewish ancestry as related in the family stories told by his great uncle Johann Peters.   Whether that ancestor was truly a redheaded Jewish woman may never be determined, but the 23andMe Ancestry Finder results certainly provide fascinating confirmation of an interesting family legend!

Tim Janzen is a family practice doctor at South Tabor Family Physicians in Portland, Oregon.   His interest in genealogical research goes back 35 years and he has particularly focused on Mennonite genealogy for the past 15 years.   He has a web site that summarizes many different sources available for Mennonite genealogical research found at <a href="http://www.timjanzen.com/">www.timjanzen.com</a> and has given many presentations about Mennonite genealogy in the United States and Canada.   He is the co-administrator of the Mennonite DNA project at <a href="http://www.mennonitedna.com/">www.mennonitedna.com</a>. He also serves on the ISOGG Y-DNA Haplogroup Tree Committee.   Tim is married to Rachel Janzen and they have four children.

Our Redheaded Jewish Grandmother

Data from the 2010 census showed that about 13% of people living in the United States self-identify as African American, but from a genetic point of view, ethnicity isn&#8217;t so black and white.
Most African Americans have genetic ancestry tracing back to both Africa and Europe but the exact proportion can vary widely. And conversely, many Americans who consider themselves of completely European descent may actually have some African ancestry as well.
A<a href="https://www.pnas.org/content/107/2/786" target="_blank" rel="noopener noreferrer"> study</a> published a few years ago found that the <a href="../2010/01/11/large-study-reveals-details-of-african-american-genetic-ancestry/" target="_blank" rel="noopener noreferrer">average amount of DNA in an African American’s genome</a> that could be traced back to West Africa was about 77%, but ranged from as little as one percent to as much as 99%.
At 23andMe, researchers have looked at the genetic ancestry of about 78,000 customers likely to consider themselves as entirely of European ancestry and found that somewhere between three to four percent of those people have <a href="https://blog.23andme.com/articles/hidden-african-ancestry" target="_blank" rel="noopener noreferrer">“hidden” African ancestry</a> ranging from 0.5 to 0.75 percent. These findings suggest that this group of customers have an African ancestor who lived about six generations, or about 200 years, ago.
The United States is often referred to as a “melting pot” and although African Americans comprise the largest racial minority, this country is also home to many other genetically mixed groups. Indeed, Americans with ties to Latin America typically have DNA deriving from <a href="http://www.plosgenetics.org/article/info%3Adoi%2F10.1371%2Fjournal.pgen.1000037" target="_blank" rel="noopener noreferrer">Native American, European and sometimes African</a> populations.
By studying genetic ancestry, researchers can break down the proportion of a person’s DNA that traces to different parts of the world and learn more about our unique and interconnected histories.
February is<a href="http://www.history.com/topics/black-history-month" target="_blank" rel="noopener noreferrer"> Black History Month</a> – stay tuned for more posts!
Did you know? provides tidbits of information about genetics (in humans and in other animals) and explains how DNA relates to both ancestry and health.

Did You Know? Ancestry is Not So Black and White

They had bigger brains and muscles, but for some reason Neanderthals died out about 30,000 years ago, while we modern humans survived.
Why we, Homo sapiens, flourished and our <a href="https://blog.23andme.com/articles/neanderthal-fade-away">Homo neandertalensis cousins died out</a> after thriving for hundreds of thousands of years is an evolutionary mystery biologist are trying to unravel.
In the last few years, scientists have uncovered clues what the <a href="https://blog.23andme.com/articles/why-23andme-love-neanderthals-and-you-should-too">lives of Neanderthals may have been like</a>. And those clues also tell us more about what it means to be a modern human.
(Discover if you have Neanderthal DNA with 23andMe&#8217;s <a class="waffle-rich-text-link" href="https://www.23andme.com/dna-ancestry/">DNA Ancestry Service</a>, or sign-up for a <a class="waffle-rich-text-link" href="https://www.23andme.com/membership/">membership</a> to unlock even more ancestry insights.)
<img loading="lazy" decoding="async" class="alignright size-full wp-image-3359" title="neanderthaler_278" src="https://blog-api.23andme.com/wp-content/uploads/2009/04/neanderthaler_278.jpg" alt="" width="278" height="206" />
<h6>Ancient DNA</h6>
Most interesting of all is that, although Neanderthals disappeared long ago, their DNA lives on in all non-African people.
23andMe now offers a <a href="https://www.23andme.com/you/labs/neanderthal/">lab</a> allowing customers to connect with their prehistoric roots.
The lab, developed by one of our resident computational biologists Eric Durand, compares two modern human genomes with the Neanderthal genome. It can then determine what percentage of your own DNA is Neanderthal. Before coming to 23andMe, Eric worked on the <a href="http://www.sciencemag.org/site/special/neandertal/" target="_blank" rel="noopener noreferrer">first draft of the Neanderthal genome</a> and on analysis of <a href="https://www.nature.com/nature/journal/v468/n7327/abs/nature09710.html" target="_blank" rel="noopener noreferrer">the Denisova genome</a>, another of our early human cousins. The lab uses the same method Eric helped develop while working at the Department of Integrative Biology at the University of California, Berkeley.
See Eric’s white paper for a technical explanation of the methodology.

<h6>Modern Humans</h6>
Most people have <a href="https://www.23andme.com/dna-ancestry/">Neanderthal DNA</a>, on average about 2.5 percent. But there are outliers, who have much more.
What it means to have a higher percentage of Neanderthal DNA – whether you’re hairier, or brutish or short, for instance – isn’t known.
There are some theories, however, of how Neanderthals contributed to modern humans. One is that interbreeding gave us some sort of <a href="https://www.nature.com/news/2011/110809/full/476136a.html">“hybrid vigor,”</a> according to Peter Parham, a geneticist at Stanford University School of Medicine.
At the very least research appears to support the theory that at some point during the tens of thousands of years Neanderthals and modern humans lived side by side, a few of them may have<a href="../2010/05/06/new-evidence-suggests-interbreeding-between-humans-and-neanderthals/"> shacked up</a>.
Or as Elizabeth Kolbert deftly phrased it in the<a href="https://www.newyorker.com/reporting/2011/08/15/110815fa_fact_kolbert#ixzz1fPOs2vp2"> New Yorker</a>: 
“Before modern humans ‘replaced’ the Neanderthals, they had sex with them.”
Provocative to say the least, but it’s actually an idea that’s floated around for some time.
Anybody who ever read Jean M. Auel’s saucy prehistoric romance books beginning with<a href="http://books.google.com/books/about/The_Clan_of_the_Cave_Bear.html?id=4gOtkoiJIjEC"> “Clan of the Cave Bear”</a> could tell you that. But the notion that modern humans and Neanderthals got way past first base. They hooked up and even had children together still doesn’t tell us much about what it means now to have a smidgen of Neanderthal in your DNA.
<h6>Neanderthal Genome</h6>
Svante Paabo, the Swedish geneticist behind the sequencing of the<a href="http://www.eva.mpg.de/neandertal/index.html"> Neanderthal genome</a>, explains that from an evolutionary point of view. Comparing the modern human’s genome to that of the Neanderthal has great value, Paabo said.
Humans and Neanderthals share a common ancestor with chimpanzees – our next closest mammalian relative – that goes back between five and seven million years.
Comparing the human genome with that of chimps tells us a lot about evolution over millions of years. But by having the Neanderthal genome sequence – now 55 percent completed – and comparing that with modern humans, we can learn much more about evolutionary changes over the last 30,000 years.
It may be that the DNA of other prehistoric human groups also are intermixed in our own DNA.
<h6>Other Ancient Cousins</h6>
Much like with Neanderthals, scientists extracted ancient DNA from the skeletal remains of another ancient cousin known as the<a href="../2010/03/24/analysis-of-ancient-dna-suggests-the-existence-of-previously-unknown-type-of-extinct-human-ancestor/"> Denisovans</a>. The remains – a finger bone – were found in a cave in Siberia and showed that Denisovans were cousins of Neanderthals. They lived in Asia and disappeared about 40,000 years ago. Their DNA is found today in Melanesians.
As for the comparisons with the Neanderthals, so far, Paabo’s team has found almost 80 genetic variants that are unique to modern humans. The function of these variants could help us understand what distinguishes us from Neanderthal.
Apparently Paabo’s work has also resonated beyond the scientific community as well.
At a talk late last year, Paabo told a group of neuroscientists that for months he’s been keeping emails from people who have<a href="http://www.guardian.co.uk/science/blog/2011/nov/16/dear-professor-husband-neanderthal"> claimed that they were Neanderthal</a> and should be included in his study. Several women have written to him volunteering their husbands as subjects for study.
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Got Neanderthal DNA?
23andMe customers can find their inner Neanderthal or at least how much Neanderthal DNA they have at <a href=" https://www.23andme.com/you/labs/neanderthal/">23andMe Ancestry Labs</a>. Not yet a customer? <a href="https://www.23andme.com/store">Visit our store</a>!
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Find Your Inner Neanderthal

It started innocently enough with a simple question from his daughter.
“Where did our family come from?”
<img loading="lazy" decoding="async" class="alignright size-full wp-image-9594" title="Vicksburg 014 Jan 08" src="https://blog-api.23andme.com/wp-content/uploads/2011/08/Vicksburg-014-Jan-08.jpg" alt="" width="226" height="170" />(Image from Larry Vick&#8217;s <a href="http://vickfamilyhistory.blogpost.com/" target="_blank" rel="noopener">blog</a>)
For 20 years Larry Vick has been trying to answer that question. His first source was a chart drawn up by an uncle, but since then Vick has turned to old Census files, birth certificates and historical documents to piece together his family tree. It’s grown to 40 pages that trace ancestors back to the early 1600s in colonial America and another branch of the family back to Germany.
He traced the origin of his family name, and created a whole website on the study of the <a href="http://vickfamilyhistory.blogspot.com/" target="_blank" rel="noopener">name Vick</a>.
Retired from the Air Force, Vick is fascinated by genealogy, so when he learned about “genetic genealogy” and the ability to trace ancestry through DNA, he decided to give it a try.
He first used 23andMe in 2009.
“My most distant (that I can identify) paternal line ancestor (Y-DNA) was Joseph Vick of Lower Parish, Isle of Wight Co., VA, born about 1640-1650,” Vick said. “My most distant maternal line ancestor (mtDNA) was Elizabeth, born about 1792 in NC.”
The test also revealed some surprises.
He noticed on his maternal line African ancestry. “I thought, ‘that’s an artifact,’” he said.
But what he found was that his mother’s 2nd great grandmother, Elizabeth Collins, probably did indeed have some mixed ancestry. She’d come from an area in Tennessee called Newman’s Ridge, where people often referred to themselves as “Black Dutch.” The population there – and in the Cumberland Gap area of Appalachia – was also referred to as “<a href="https://en.wikipedia.org/wiki/Melungeon" target="_blank" rel="noopener">Melungeon</a>,” tri-racial with a mix European, African and Native American ancestry.
Vick’s use of 23andMe’s ancestry finder also helped him track down a distant cousin – who also happened to share his interest in genealogy. They traced back their connection to a common ancestor in pre-revolutionary America. That story was picked up by CNN three years ago.
While Vick’s interest is primarily in the ancestry functions of 23andMe, he said the service offers more.
“At first I had no interest in the health side,” Vick said.
That has since changed he learned his granddaughter, who has also been tested by 23andMe, had a high risk for deep vein thrombosis. He immediately talked to his daughter. Since neither he nor his daughter had an elevated risk for deep vein thrombosis, it appeared his granddaughter had inherited this risk from his son-in-law’s side of the family. Because his son-in-law was adopted and did not know anything about his biological parents’ health history, the insight about this risk told them something they otherwise would not have known. This risk can be heightened for women who are also taking an oral contraception, hormone replacement or who are pregnant.
Vick said that because the number of people who use 23andMe, its power grows.
“It’s kind of like panning for gold, when you find a relative it can be golden,” he said.
23andMe provides genetic testing services for informational purposes; your results may or may not help you to search for or identify relatives or family members.
What&#8217;s your story? If you&#8217;re willing to share, we want to hear. Drop us a line at <a href="mailto:stories@23andme.com">stories@23andme.com</a>.

Stories From 23andMe: James Larry Vick and the “Black Dutch” of Newman’s Ridge

<img loading="lazy" decoding="async" class="alignright size-full wp-image-6513" title="joanna_africa4" src="https://blog-api.23andme.com/wp-content/uploads/2010/05/joanna_africa4.jpg" alt="" width="357" height="246" srcset="https://blogcms.23andme.com/wp-content/uploads/2010/05/joanna_africa4.jpg 357w, https://blogcms.23andme.com/wp-content/uploads/2010/05/joanna_africa4-300x207.jpg 300w" sizes="auto, (max-width: 357px) 100vw, 357px" />The author during her time as a Peace Corps volunteer in Kenya.
As a Peace Corps volunteer teaching in Kenya 25 years ago, I was fascinated by the cultural, linguistic, and physical differences among the people of eastern Africa. One of our Kenyan trainers took us to a &#8220;boma&#8221; where his tall, cattle-herding Maasai-speaking family lived.   Once I began working, I lived with a Luo-speaking fellow teacher who emphasized the cultural differences, for instance in circumcision practices, between the Luo and other ethnic groups.   Later I taught Bantu-speaking children of farmers and fishermen along the coast of Kenya. Physical features hinted at ethnic identity and, even within the village where I taught, skin color ranged from quite light to relatively dark.   At the time I saw patterns, but understood little of the history behind those patterns.
Upon returning to the United States, I was fortunate to join the lab of geneticist Luca Cavalli-Sforza, who was studying the genetics of people across Africa. At that time, relatively little was known about human genetic diversity, in particular for Africa. I leaped at the opportunity to compare the hidden dimension of genetic diversity with the linguistic and cultural variation that I had observed in Kenya. In the 25 years since then, the study of diversity in Africa has blossomed. Thanks to advances in DNA technology, researchers have begun to augment information about the cultural and linguistic variation with information about how Africans differ at the genetic level. Online last week in the <a href="https://dx.doi.org/10.1073/pnas.1002563107" target="_blank" rel="noopener">Proceedings of the National Academy of Sciences</a>, authors Laura Scheinfeldt, Sameer Soi and Sarah Tishkoff pulled together recent discoveries about the population history of Africa based on languages, artifacts and DNA. Their paper paints the prehistory of the continent in broad strokes, beginning over 100,000 years ago.
(This paper is one of many to come out of In Light of Evolution IV: The Human Condition Sackler Colloquium presented by the National Academy of Sciences in December 2009.   Links to other papers from this series can be found <a href="https://www.pnas.org/content/early/recent" target="_blank" rel="noopener">here</a> (after this week they should be here.).   Podcasts of presentations from the colloquium can be found here.)
As these authors note, the genetic data indicating that our species originated in Africa has accrued significantly and convincingly. And we now know that today&#8217;s African populations began forming over 50,000 years ago. From among those early populations, a relatively small group of individuals migrated out of Africa to populate Eurasia and Oceania. Within Africa, meanwhile, technological innovation (such as the use of more refined stone tools, and later, iron tools) and the development of today&#8217;s language families paralleled the formation of today&#8217;s ethnic groups.   The combination of archaeological, linguistic and genetic data has revealed that some populations remained relatively isolated from one another for tens of thousands of years, but that interactions between groups, especially within the last 5,000 years, have also shaped the genetic diversity of the continent. For instance, the DNA is very clear in revealing the interactions between migrating agriculturalists and pastoralists and the hunter/gatherers who they encountered.
As a result of the rich prehistory outlined in this paper, today&#8217;s Africans can trace their ancestry to central and southern Africa, where a few click-speaking <a href="http://ngm.nationalgeographic.com/ngm/0102/feature6/" target="_blank" rel="noopener">Khoe-San peoples</a> continue to subsist through hunting and gathering; to northern Africa, where migrations of <a href="http://www.azawan.com/" target="_blank" rel="noopener">Afro-Asiatic speakers</a> from the Middle East to the western coast have been taking place for 14,000 years; to the Sahel region near the equator, where Nilo-Saharan (including Luo) and Afro-Asiatic speakers have traveled back and forth from eastern Sudan to <a href="http://earthshots.usgs.gov/LakeChad/LakeChad" target="_blank" rel="noopener">Lake Chad</a> for at least 10,000 years; or to western Africa, where the innovations of agriculture and iron age technology supported the migration of Bantu-speaking peoples to all corners of Sub-Saharan Africa within the last 4,000 years.   And, of course, many Africans trace ancestry to multiple corners of Africa and to other continents as well.
As one of the authors, geneticist Sarah Tishkoff, noted when I spoke with her recently, &#8220;The strength of this paper is the deep integration of the genetics, linguistics, and archaeology.&#8221; With this synthesis of 25 years of research in mind, I see the diversity that I observed in Kenya in a continental context. The Maasai-speaking Peace Corps trainer undoubtedly had ancestors 4,000 years ago who lived further north in eastern Africa, and may now have distant cousins whose ancestors migrated to southern Africa with their cattle 2,000 years ago.   My fellow teacher who spoke Luo inherited her language, cultural traditions and some DNA from her eastern African Nilo-Saharan ancestors, but, according to this PNAS article, probably also traced quite a bit of ancestry to Bantu-speakers of western Africa. My Bantu-speaking students were descendants of migrants from western Africa, but Arab slavery within the last several hundred years may explain some of the lightness of their skin color.   Understanding the prehistory of the people I worked with has led me to appreciate, more than ever, the opportunity I had as a Peace Corps volunteer to know such a diverse set of people.
23andMe has supported several initiatives that are contributing to the understanding of genetic diversity within Africa.   In fact, 23andMe provided funding for one of the studies (<a href="https://www.ncbi.nlm.nih.gov/pubmed/18292342" target="_blank" rel="noopener">Li et al, 2008</a>) reviewed in this paper, knowing that the study would enable 23andMe to provide richer interpretations of customers&#8217; data. I am looking forward to further discoveries that strengthen our understanding of where we, as a species and as individuals, have come from.

The genetics of hunter-gatherer populations

In our last post we highlighted a few of the coolest (in our opinion!) health-related developments of 2009.   But human genetics isn&#8217;t all about disease.   Here are a few more favorites:
The Romanovs
2009 saw the identification of the remains of the missing members of this Russian royal family, as well as identification of the mutation that caused the hemophilia that plagued their youngest son.
<a href="https://blog.23andme.com/articles/leaving-no-stone-unturned-dna-analysis-confirms-identities-of-missing-romanovs" target="_blank" rel="bookmark noopener">Leaving No Stone Unturned: DNA Analysis Confirms Identities of Missing Romanovs</a>
<a href="https://blog.23andme.com/articles/researchers-discover-the-true-identity-of-the-royal-disease" target="_blank" rel="bookmark noopener">Researchers Discover the True Identity of the “Royal Disease”</a>
The Celtic Fringe
The genetics of adorable little critters helped scientists understand the prehistory of the British Isles.
<a href="https://blog.23andme.com/articles/life-on-the-fringe-shrews-and-voles-reveal-clues-to-british-prehistory" target="_blank" rel="bookmark noopener">Life on the Fringe: Shrews and Voles Reveal Clues to British Prehistory</a>
Link Between Australian Aborigines and India
Scientists discovered mitochondrial DNA markers shared by isolated tribes in India and native Australians&#8230;and nobody else.
<a href="https://blog.23andme.com/articles/direct-genetic-link-between-australia-and-india-provides-new-insight-into-the-origins-of-australian-aborigines" target="_blank" rel="bookmark noopener">Direct Genetic Link between Australia and India Provides New Insight into the Origins of Australian Aborigines</a>
Largest Ever Study of Modern African Genetics 
2,432 DNA samples from 113 diverse and distinct groups of people from across the African continent as well as 60 non-African groups. Everyone from the Mozabite Berbers of Morocco to the hunter-gatherer San of the Kalahari Desert, and many in between.
<a href="https://blog.23andme.com/articles/scientists-publish-largest-ever-study-on-the-genetics-of-modern-africans" target="_blank" rel="bookmark noopener">Scientists Publish Largest-Ever Study on the Genetics of Modern Africans</a>
Dogs
We can&#8217;t forget all those dog genetics studies.   Man&#8217;s best friend is certainly a friend of the Blog&#8217;s!
<a href="https://blog.23andme.com/articles/single-gene-responsible-for-stubby-legs-in-dogs" target="_blank" rel="noopener">Single Gene Responsible For Stubby Legs In Dogs</a>
<a href="https://blog.23andme.com/articles/whence-rover-genetic-study-suggests-africa-may-have-whelped-mans-best-friend" target="_blank" rel="noopener">Whence Rover? Genetic Study Suggests Africa May Have Whelped Man’s Best Friend</a>
<a href="https://blog.23andme.com/articles/study-sniffs-out-genes-behind-doggy-dos" target="_blank" rel="noopener">Study Sniffs Out Genes Behind Doggy ‘Dos</a>

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