My surname — Holden — has gone through many incarnations since it originated in England nearly 700 years ago.  Letters were added, then dropped.  Some branches of my family added an extra “u” in the middle, while others changed the pronunciation entirely.  Then, when my ancestors arrived in America over 200 years ago, the name went through a whole new set of changes.  It seems my surname has been in a constant state of change since its inception.

But the story of my surname is not unique.  Millions of Americans have similar stories about ancestors who, upon arriving in the New World, actively changed their names to sound more “American.” German immigrants named Blum became Bloom, Küsters became Custers, and Kÿfers became Coopers. Immigrants from Italy, Sweden, France, and countless other countries underwent similar transformations.  After just a few generations, the original spelling or pronunciation was lost.

Just as our surnames have changed over the centuries, little by little, so too has our DNA.  In fact, some regions of the human genome acquire mutations in such a way that researchers can trace the changes back through time – much like tracing a surname back for generations in a family tree.  And one region in particular, the Y-chromosome, happens to be passed down from father to son, the same way surnames are inherited in Western culture. That provides a wealth of opportunities for scientists from a variety of disciplines to use the Y-chromosome to unlock history’s secrets, unravel family trees, and even solve crimes.

The Genetic Legacy of the Vikings

The histories of Scandinavia and the British Isles have been entwined since Vikings from Norway and Denmark landed on the eastern coast of England in the year 792.  Successful raiding parties eventually led to settlements along the eastern half of England.  Today there are remnants of Viking settlements in this region in the form of place names, unique vocabulary, and even surnames.  Last year, British geneticists took surname information from an area formerly settled by Vikings to see if men living there today who had Scandinavian surnames also had evidence of Scandinavian (aka Viking) genetic ancestry.  They analyzed the Y-chromosomes of several hundred men, and, not surprisingly, found that those with Scandinavian surnames did indeed have Scandinavian DNA, at least on the Y-chromosome.  Similar studies of Irish men have also found a modest connection between surnames and Y-chromosome types.

Surname DNA Projects

As we reported several weeks ago, the field of genealogy has been invigorated by the increasing use of genetic testing to fill in the missing branches of a person’s family tree.  Genealogists are now comparing their Y-chromosomes to those of others with the same surname, to see if a shared surname is also an indication of the shared ancestry.  Within the past few years, surname DNA projects have sprung up all across the world – with hundreds of genetic genealogists digging deep into their genes as they piece together their detailed family trees.

Surnames and Forensics

By far one of the most interesting applications for surname and Y-chromosome comparison is in the field of forensic science.  In 2006, British geneticists found that – for some of the more rare surnames such as Maloy or Rivis, there was a strong connection between surname and Y-chromosome haplogroup.  The authors reasoned that, if DNA were to be recovered from a crime scene, forensic investigators might be able to narrow down the possible perpetrators to a specific subset of surnames.

However, there are several limitations to this idea – namely the fact that most men in the UK have rather common surnames, such as Smith, Green, and Adams.  Men with these surnames have a wide range of Y-chromosome DNA types, so it would nearly impossible for investigators to use the Y-chromosome to locate a suspect.  However, on principle this idea has merit, and further advances along these lines may someday allow investigators to exploit the DNA-surname connection.

One final note: 23andMe customers need not worry that their data will be used in this way — our research database does not include surnames and our terms of service do not allow us to share data with law enforcement unless we are legally compelled to. And even if such a situation did arise, we have publicly committed to resisting legal requests for customer data.

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Because their ancestors often were slaves during the 18th and 19th centuries, and therefore usually lacked birth or death certificates, it is very difficult for African American genealogists to trace their ancestors further than a few generations. Even when they can trace their ancestry to the slavery era, it is virtually impossible to find exactly where their ancestors originated because slave ships did not keep passenger lists of the people they captured from Africa.

As a consequence, many have been turning to genetics as a tool to help trace their African ancestry. But how reliably can genetics trace a person’s ancestry back to a specific African location or ethnic group? Using genetics this way is quite complex; even the most advanced analysis can’t provide all the answers.

Relying on genetic data for genealogical purposes can be problematic, especially if your expectations are too great. For example, Henry Louis Gates, Jr., the Director of the W.E.B. Du Bois Institute for African and African American Research at Harvard, had his Y-chromosome genotyped by two different companies. The first told him that his ancestors likely traced back to Nubia or Egypt, while the second test more accurately placed his paternal ancestry in Europe. As an African American, Gates believes that the first company may have simply ‘told him what he wanted to hear’: that all of his ancestry traced back to Africa. But, as is often the case, one’s genetic ancestry can be more complex than meets the eye.

One problem is that genetic analyses predominantly trace deep ancestry. Because genetic information does not change significantly within one or two generations, genetics generally shows where a person’s ancestors lived thousands of years ago. This is hardly useful to genealogists who are looking for information about ancestors who lived only a few hundred years ago.

That isn’t to say we can’t learn anything useful about the deep ancestry of many African Americans – in fact, studies of genetic ancestry have yielded much information about prehistoric population movements across the continent. For example, there are clear genetic ‘footprints’ in modern Africans — and African Americans — indicating massive expansions of Bantu-speaking peoples from West Africa into the eastern and southern part of the continent over 4,000 years ago. This has helped archaeologists understand the extent to which not only the Bantu culture and language, but the people themselves, spread throughout the continent.

Most African Americans have the signature of this Bantu migration in their genes because they are descended from populations that were affected by it. But many, including Gates, have the genetic signature of another widespread group: Europeans. Indeed, European ancestry is not uncommon among African Americans, whose ancestors can include white slave owners who fathered children with their slaves. The use of genetic data can be useful in confirming anecdotal evidence of a non-African ancestor in an African American’s family tree.

Many African American genealogists want greater detail and resolution from their genetic information, even a link to a specific nation or tribe. But in many cases this is simply not possible. The population history of Africa – especially sub-Saharan Africa – is older and more genetically complex than that of any other region of the world. Homo sapiens evolved in East Africa more than 150,000 years ago, and has been living throughout Africa continuously since that time. There have been countless migrations, dispersals, and expansions of African peoples to all parts of the continent – in addition to the Bantu expansions. As a result, the genetic diversity of present-day Africans is incredibly complex.

In many cases, scientists are unable to associate a specific genetic classification with a specific tribe or ethnic group. There are of course a few exceptions – isolated hunter-gather groups like the !Kung of the Kalahari Desert and the Pygmies of the Central African Rainforest have lower levels of genetic diversity as a result of their relative isolation. But in West Africa, where the majority of slaves were captured, there is significant genetic diversity both within countries and within tribal or ethnic affiliations. The high level of diversity means that scientists have a difficult time pinpointing where a particular person’s genetic roots trace beyond a more general geographical region (i.e. West Africa). For example, the paternal haplogroup E3a, found in more than half of African American men, is just as common in Africa itself – and spread throughout the continent. So, for an African American male who’s paternal ancestry falls within the E3a haplogroup, it could be virtually impossible to narrow down the place of origin of his African ancestors.

Still, when traditional tools are unavailable or incomplete genetics can reveal useful genealogical information, whether a person’s roots trace back to Africa, Europe, or someplace else entirely.

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People naturally yearn to know where they came from. Genealogists scratch that itch by poring over historical documents such as vital records, tax rolls, census lists and diaries to reconstruct their family history.

In recent years, genealogists have also begun using genetic information as another way of understanding their identity and establishing kinship. With the growth of several genetics companies specializing in genetic ancestry – including 23andMe’s Personal Genome Service™ – genealogists now have an entirely new approach to use in tracing their roots. DNA is especially useful for recent immigrants, Native Americans or African-Americans whose ancestors left few historical records, but passed down a trail of genetic breadcrumbs that can lead back to a specific geographic region – and in some cases even a particular tribe.

The growth of genetic ancestry services, combined with the availability of resources on the internet, has also led many genealogists to share their stories and connect with others. Now Roots Television is adding viral video to the modern genealogist’s tool box. Roots Television markets itself as a video-based genealogy website, created for and by avid genealogists and family history lovers. They create online web shows on a variety of topics, while also licensing other programs. A recent glance at their programming line-up revealed a brief video on the art of document restoration, interviews with well-known genealogists, and reviews of new genealogy computer software. There is even an area of the site dedicated to user-submitted video, called RootsTube. Here, anyone can tell their story – whether it is an interesting discovery about their family history, a family reunion video, or even a tip on how to best utilize a particular genealogy resource.

So far there isn’t much content related to genetic genealogy, but the website is still in its infancy; we hope to see more genetics-related content over time.

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