The Genetic Genealogist

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I received the following press release today from SMGF:

SALT LAKE CITY (Dec. 30, 2008)—Genetic research by the Sorenson Molecular Genealogy Foundation (SMGF) and scientists from ten organizations in Europe and the U.S. shows human groups with the deepest roots in southeastern Europe were not pushed out by an incoming wave of farmer-colonists as agriculture first spread into Europe. Instead, indigenous Europeans with a hunting and gathering lifestyle adopted agriculture when it was introduced by settlers from the Middle East. The study was published in the Dec. 24, 2008 online issue of European Journal of Human Genetics.

Scientists have long debated the question of how agriculture spread into Europe from its birthplace in the Fertile Crescent region of the Middle East. But the evidence—primarily archaeological—is inconclusive.

Applying molecular genetics to the question, an international team of researchers studied the Y-chromosomes, or paternally inherited DNA, of 1,200 men living in southeastern Europe where evidence of farming in Europe first occurs. If agriculture had spread there by Middle Eastern colonizers replacing an indigenous population, most of today’s southeastern Europeans should have Middle Eastern genetic roots.

But researchers found a large majority of southeastern European males are descended from genetic groups with roots in Europe that predate the change to an agricultural lifestyle. The strong inference is that farming spread culturally as local people adopted the technology.

Settlers from the Middle East were Europe’s first farmers. “Middle Eastern agriculturalists initially brought farming into southeastern Europe,” said Natalie Myres, study co-author and director of research and development for SMGF. “However, descendents of those first farmers do not dominate today’s gene pool. Most of the men in the study descend from people who lived in southeastern Europe well before the advent of farming.”

Genetic scientists can test theories about ancient human history developed primarily by other disciplines by studying the DNA of people living today. Certain DNA markers found in today’s populations originated in ancient ancestors and have been passed through the generations essentially intact, and because DNA has a built-in molecular clock, scientists can estimate the timing and geography associated with our ancient ancestors’ movements.

This study found three major groups of interest. First, the European DNA groups, haplogroups I and R, make up about 60 percent of today’s population in southeastern Europe and represent some of the earliest modern humans to have occupied Europe, stretching back into Paleolithic times. Second, haplogroup E entered southern Europe from Africa’s eastern Sahara and became established in the region roughly 10,000 years ago. Third, haplogroup J is Middle Eastern and likely introduced agriculture into southeast Europe around 8,500 years ago.

Both of the two later-arriving lineages, haplogroups E and J each make up 20 percent or less of the region’s population. Lineages E and J are found predominately in the southern part of the Balkans, the region where Middle Eastern immigrants would have entered the area and where the first pottery associated with a farming society in the region is also observed. The study proposes that the haplogroup J lineage introduced farming to the inhabitants of the southern Balkans represented by haplogroup E. Members of haplogroup E subsequently transmitted the farming technology along the Adriatic where it was readily adopted by indigenous Europeans represented by haplogroup I.

“The central finding of this study is important because it illuminates our past, showing us how we became who we are today,” said Myres. “When these different ancient population groups met—Mesolithic foragers and Neolithic farmers—the outcome was productive and positive.” But Myres said the way agriculture spread to the rest of Europe can’t be generalized from this study since other regions in Europe appear to have followed a different model.

“We are gaining powerful insights into the deep history of the human family by correlating evidence from molecular genetics with research from other disciplines,” said Dr. Scott Woodward, executive director of SMGF and a prominent genetic researcher. “This study points the way for future investigations using the same methods in other regions.”

Scientists for the study came from the University of Pavia, Italy; Stanford University; University of Tartu, Estonia; Universities of Sarajevo and Banja Luka, Bosnia and Herzegovina; Split and Osijek Universities and Genus doo, Croatia; Forensic Laboratory and Research Center, Slovenia; and University of Tetovo, the former Yugoslavia Republic of Macedonia. The study entitled, “Y-chromosomal Evidence of the Cultural Diffusion of Agriculture in Southeast Europe,” is now available online to subscribers at http://www.nature.com/ejhg/ and will be published in an upcoming print issue of European Journal of Human Genetics.

About Sorenson Molecular Genealogy Foundation

The Sorenson Molecular Genealogy Foundation (SMGF; www.smgf.org) is a non-profit research organization that has created the world’s largest repository of correlated genetic and genealogical information. The SMGF database currently contains information about more than seven million ancestors through linked DNA samples and pedigree charts from more than 170 countries, or approximately 90 percent of the nations of the world. The foundation’s purpose is to foster a greater sense of identity, connection and belonging among all people by showing how closely we are connected as members of a single human family. For more information about the foundation’s free, publicly available database, visit www.smgf.org.

Note: there are some great X chromosome inheritance charts below – if you are unable to see them, be sure to click through to the original post!

Most genetic genealogists have sent away their cheek swabs to learn about their mitochondrial DNA or their Y-DNA lines.  Others have explored their autosomal DNA for ancestral information, a field that is growing quickly and will undergo rapid changes as the price of sequencing continues to fall.

Now genetic genealogists are beginning to discover the ancestral information locked away in the X chromosome.  Indeed, X chromosome tests have been offered by companies such as Family Tree DNA for a number of years.  Armed with some of this information as well as the advent of SNP chip information from 23andMe and deCODEme,  genetic genealogists are making new discoveries in this very young arena.

Inheritance of the X Chromosome

To help you understand some of the X chromosome data, I’ve prepared this short summary regarding the unique and interesting inheritance of the X chromosome.  Males, of course, have one Y chromosome from their father and one X chromosome from their mother.  Females have two X chromosomes, one from each parent.

The charts below trace back the inheritance of the X chromosome through the level of GGGGG-grandparents.  At that generation, a person has 128 ancestors.  Of these 128 ancestors, a male will have 21 people who potentially contributed to their single X chromosome (8 males and 13 females).  A female will have 34 potential contributors to her two X chromosomes (13 males and 21 females).  Note that I say “POTENTIAL” contributors because it is unlikely that all these ancestors are equally represented in the X chromosome – it is more likely that some ancestors are completely missing while others are well-represented.

What I found to be particularly interesting is that the number of X contributors at each generation follows the Fibonacci sequence of 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233… (HT: John Chandler).  A male will start with 1 X contributor and then follows through the sequence, while a female will start with 2 X contributors and follow through the sequence (although the numbers will be different if there is recent overlap in your family tree, as there is in mine).

Male Inheritance (click to enlarge) – Male contributors are in blue and female contributors are in pink:

Female Inheritance (Click to enlarge)  – Male contributors are in blue and female contributors are in pink:

More Information

You can find more information about recent developments in the X chromosome field at the following:

• X chromosome applications by Kathy Johnston (registration required)
• Finding X Eve – Block 3 by David Faux
• X chromosome resource list by David Faux
• X chromosome block 3 by David Faux
• Matching X chromosome block by Kathy Johnston
• Summary 1 and Summary 2 and Summary 3 by David Faux

Conclusion

It is important to keep in mind that this investigation into the X chromosome is VERY new and thus can be confusing or unclear.  While I don’t recommend jumping into this area if you aren’t ready for the many changes, reversals, or dead-ends that will undoubtedly appear, I would encourage anyone who is interested in assisting these researchers contribute their own information if you feel completely comfortable doing so.

It will be very interesting to see how this field develops over the next few years.

P.S. – Feel free to use these charts, all I ask is that I be credited with a link to the blog.

UPDATE: Ann Turner has a text file of the Ahnentafel numbers of those ancestors who potentially contributed to the X chromosome, through 10 generations.  If you are a male, be sure to start the ahnentafel chart with your mother.

The Virginia Commonwealth University Life Science Center has released the results of the VCU Life Sciences Survey and I thought I’d share some of the interesting results.

The most surprising result of the survey is that 80% of surveyed adults favor making genetic testing “easily available to all who want it,” similar to values in 2001 and 2004.  Don’t tell this to the New York and California Departments of Health!

The Benefits Outweigh the Risks

54% of adults believe that the benefits of genetic testing outweigh the risks, while 25% believe that the risks outweigh the benefits.  It’s interesting to see the education breakdown of this question.  44% of people with a high school degree or less believe that benefits outweigh risks, compared to 67% of people with a college degree or more.  And 29% of people with a high school degree or less believe that risks outweigh benefits, compared to 20% of those with a college degree or more.

Nature vs. Nurture

So which is stronger – our genetic inheritance or our lifestyle/environment?  57% of respondents believe that “our environment and living practices” are “a more important influence on people’s behavior, while 27% believe that it is “the genes we inherit.”  The respondents were also asked how scientists would respond to the same question.  They believed that 42% of scientific experts would say that our genes are a more important influence and 39% would say that our environment and living practices are more influential.

Further Information

See the following links for more coverage of the study: VCU News Center; GenomeWeb News (free reg. required); ScienceDaily.

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I’m currently in the middle of third-year law school exams, so I thought I’d do a round-up of all the interesting stories I’ve seen over the past week or two.

Holiday Specials on DNA Testing

First, it appears that most of the major genetic genealogy companies are offering special deals for the holidays:

Family Tree DNA announces a holiday sale – FTDNA is offering reducing pricing for customers who are part of or join a DNA project.  For example, a 37-marker Y-DNA test is reduced to $119, down from $149.

Ancestry.com announces holiday sale – buy a DNA test between now and December 31st, and you’ll receive 40% off.  For example, a 33-marker Y-DNA test is $89.40 (usually $149) and their mtDNA test is $107.40 (usually $179).

African Ancestry announces a holiday sale – their MatriClan and PatriClan tests, which are normally $349, are on sale for $275.

Genetree offers a special first birthday sale – I’m not sure if this sale is open to everyone or only to those who have already tested, but the relatively new company Genetree is offering $30 off the purchase of a testing kit.  I covered the launch of Genetree back in October 2007.

23andMe Announces Holiday Season Multi-Pack Discount – Customers who purchase three or more kits in a single order will save $200 on the first three kits and $70 for every additional kit.

As always, before buying a genetic genealogy test it is important to do the proper research to understand what you are buying and what the results could mean.

Genetic Genealogy Research Articles

A newly discovered mutation in AP1S1 gene, involved in the development of the central nervous system, has been traced to a group of families from the Kamouraska region in eastern Quebec.  The researchers used a massive genealogy database of Quebec families to trace the gene.  See more at Canada.com.

Using genetic variation to map the ancestry of Finns.  See Genetic Future’s posts here and here.

PLoS Genetics article examines the gene expression of African Americans to estimate how much of the difference in gene expression levels is due to ancestry and how much is due to something else (such as environment, etc.).  See Gene Expression, Popgen Ramblings, Dienekes’ Anthropology Blog, and Genetic Future.

A new paper that examines “The Genetic Legacy of Religious Diversity and Intolerance: Paternal Lineages of Christians, Jews, and Muslims in the Iberian Peninsula.”  To explore the rich diversity of the Iberian Peninsula, the researchers analyzed the Y-DNA of 1140 males from this region.  See more at Tracing the Tribe and Dienekes’ Anthropology Blog.

“Re-creation of the genetic composition of a founder population.”  There will be many more of these types of papers in the future as genetic genealogists try to recreate the genomes of their ancestors (yes we will, believe it or not!).  HT: Yann Klimentidis’ Weblog.

Genetic Genealogy in the News

News from GeneaNet that “The Bodies Of Australian And British Soldiers Buried In A Mass Grave In Northern France During World War I Are To Be DNA Tested.

A new article in Ancestry Magazine, “Meeting My New Family,” details a recent meeting of genetic relatives in Chicago.  The author is Howard Wolinsky, who has written other articles in the field of genetic genealogy (see, for example, an article in EMBO about 2 years ago).  As Howard describes, the meeting wasn’t a traditional family reunion:

“We are a new kind of cousin. Until a few days ago, we were strangers who just happened to have had our DNA analyzed. Then we discovered we matched one another to varying degrees. Most of us have common Jewish connections. And we learned that we come from relatively rare branches of the human DNA tree. Our mothers’ mothers came from the HV branch. Our fathers’ fathers came from the G group.”

The full text of the article is here.

Similar to a move made by myHeritage a few weeks ago, Familybuilder has announced that it will offer genetic genealogy testing to its customers.  As part of the launch of this new product, Familybuilder is offering both Y-DNA and mtDNA tests for only $59.95 until January 1.  After that, the price will be $89.95

Based on the demo account, it looks like the Y-DNA test includes 17 markers.  Although this isn’t many markers, $3.52 per marker is a great price.

Familybuilder is planning to continue to develop their genetic genealogy offering: “Currently in development is the ability to create Groups around surnames, families, and other criteria as well as the ability to Compare DNA.”  From the press release:

“Up to now, genealogical DNA testing for the masses has been cost-prohibitive,” said David Rheins, CMO of Familybuilder.  “We are excited about the launch of Familybuilder DNA, and believe that this tool will help millions of consumers better understand the origins of their heritage and ancestry. We are very focused on developing the Familybuilder DNA product line, and have plans to roll out additional tests and future functionality, including the ability to search our DNA database to identify living relatives with whom you share DNA.”

Interestingly, Familybuilder is one of the top 50 Facebook applications.  Will this motivate Facebook genealogists to enter the field of genetic genealogy?  And, if they do, will those results be available to others to compare with without using Familybuilder?