Last modified on 17 July 2014, at 16:45

Genetic genealogy

Genetic genealogy is the application of genetics to traditional genealogy. Genetic genealogy involves the use of genealogical DNA testing to determine the level and type of the genetic relationship between individuals. This application of genetics became popular with family historians in the first decade of the 21st century, as tests became affordable. The tests have been promoted by amateur groups, such as surname study groups, or regional genealogical groups, as well as research projects such as the genographic project. As of 2013 hundreds of thousands of people had been tested. As this field has developed, the aims of practitioners broadened, with many seeking knowledge of their ancestry beyond the recent centuries for which traditional pedigrees can be constructed.

HistoryEdit

George Darwin, son of Charles Darwin, was the first to estimate the frequency of first-cousin marriages

The investigation of surnames in genetics can be said to go back to George Darwin, a son of Charles Darwin. In 1875, George Darwin used surnames to estimate the frequency of first-cousin marriages and calculated the expected incidence of marriage between people of the same surname (isonymy). He arrived at a figure between 2.25% and 4.5% for cousin-marriage in the population of Great Britain, higher among the upper classes and lower among the general rural population.[1]

Population genetic genealogyEdit

Origin of peoples in a context of DNA genealogy is an assignment of each of them to a particular tribe or its branch (lineage) initiated in a genealogical sense by a particular ancestor who had a base (“ancestral”) haplotype. This also includes an estimation of a time span between the common ancestor and its current descendants. If information obtained this way can be presented in a historical context and supported, even arguably, by other independent archeological, linguistic, historical, ethnographic, anthropological and other related considerations, this can be called a success.[2] Just in the last 20 years scientists began to use Y-chromosome markers and Mt-chromosome markers, to provide evidence of common ancestry between individuals with a tradition of common ancestry. Two notable studies showed common heritage between men from Kohen Jewish lineages.[3]

Surname studiesEdit

One famous study examined the lineage of descendants of Thomas Jefferson’s paternal line and male lineage descendants of the freed slave, Sally Hemmings.[4]

Bryan Sykes, a molecular biologist at Oxford University tested the new methodology in general surname research. His study of the Sykes surname obtained results by looking at four STR markers on the male chromosome. It pointed the way to genetics becoming a valuable assistant in the service of genealogy and history.[5]

Direct to consumer paternity testingEdit

The first company to provide direct-to-consumer genetic DNA testing was the now defunct GeneTree. However, it did not offer multi-generational genealogy tests. In fall 2001, GeneTree sold its assets to Salt Lake City-based Sorenson Molecular Genealogy Foundation (SMGF) which originated in 1999.[6] While in operation, SMGF provided free Y-Chromosome and mitochondrial DNA tests to thousands.[7] Later, GeneTree returned to genetic testing for genealogy in conjunction with the Sorenson parent company and eventually was part of the assets acquired in the Ancestry.com buyout of SMGF.[8]

The genetic genealogy revolutionEdit

In 2000, Family Tree DNA, founded by Bennett Greenspan and Max Blankfeld, was the first company dedicated to direct-to-consumer testing for genealogy research. They initially offered eleven marker Y-Chromosome STR tests and HVR1 mitochondrial DNA tests. They originally tested in partnership with the University of Arizona.[9][10][11][12][13][14][15]

The publication of The Seven Daughters of Eve by Sykes in 2001, which described the seven major haplogroups of European ancestors, helped push personal ancestry testing through DNA tests into wide public notice. With the growing availability and affordability of genealogical DNA testing, genetic genealogy as a field grew rapidly. By 2003, the field of DNA testing of surnames was declared officially to have “arrived” in an article by Jobling and Tyler-Smith in Nature Reviews Genetics.[16] The number of firms offering tests, and the number of consumers ordering them, rose dramatically.[17]

The Genographic ProjectEdit

Main article: Genographic Project

The original Genographic Project was a five-year research study launched in 2005 by the National Geographic Society and IBM, in partnership with the University of Arizona and Family Tree DNA. Its goals were primarily anthropological. The project announced that by April 2010 it had sold more than 350,000 of its public participation testing kits, which test the general public for either twelve STR markers on the Y-Chromosome or mutations on the HVR1 region of the mtDNA.[18]

In 2007, annual sales of genetic genealogical tests for all companies, including the laboratories that support them, were estimated to be in the area of $60 million (2006).[7]

Typical customers and interest groupsEdit

The earliest test takers were customers most often those who started with a Y-Chromosome test to determine their father's paternal ancestry. These men often took part in surname projects. The first phase of the Genographic project brought new participants into genetic genealogy. Those who tested were as likely to be interested in direct maternal heritage as their paternal. The number of those taking mtDNA tests increased. The introduction of autosomal SNP tests based on microarray chip technology changed the demographics. Women were as likely as men to test themselves. Further, Ancestry.com's simplification of matching brought a larger number of test takers, though the validity of their DNA matching and accompanying genealogy pairing were questioned.[citation needed]

Citizen science and ISOGGEdit

Members of the growing genetic genealogy community have been credited with making useful contributions to knowledge in the field.[19]

One of the earliest interest groups to emerge was the International Society of Genetic Genealogy (ISOGG). Their stated goal is to promote DNA testing for genealogy.[20] Members advocate the use of genetics in genealogical research and the group facilitates networking among genetic genealogists.[21] Since 2006 ISOGG has maintained the regularly updated ISOGG Y-chromosome phylogenetic tree.[21][22] ISOGG aims to keep the tree as up-to-date as possible, incorporating new SNPs.[23] The tree has been described by academics as providing the accepted nomenclature for human Y-chromosome DNA haplogroups and subclades,[24] and being "one of the most up-to-date, if not completely academically verified, phylogenetic trees of Y chromosome haplogroups".[19]

UsesEdit

Mitochondrial DNA and direct maternal lineagesEdit

mtDNA testing involves sequencing or testing the parts of the hypervariable region (HVR1 or HVR2) or the complete mitochondrial genome (mtGenome). An mtDNA test that only tests part of the hypervariable region may also include the additional SNPs needed to assign people to a maternal haplogroup.[25]

Direct paternal lineagesEdit

Y-Chromosome DNA (Y-DNA) testing involves short tandem repeat (STR) and, sometimes, single nucleotide polymorphism (SNP) testing of the Y-Chromosome. The Y-Chromosome is present only in males and reveals information strictly on the paternal line. These tests can provide insight into the recent (via STRs) and ancient (via SNPs) genetic ancestry. A Y-chromosome STR test will reveal a haplotype, which should be similar among all male descendants of a male ancestor. SNP tests are used to assign people to a paternal haplogroup, which defines a much larger genetic population.[26][27]

Biogeographical and ethnic originsEdit

Additional DNA tests exist for determining biogeographical and ethnic origin, but these tests have less relevance for traditional genealogy.

Genetic genealogy revealed links between seemingly unrelated peoples. For instance, the ancient Phoenician people were ancestors of the present-day population of the island of Malta. Preliminary results from a study by Pierre Zalloua of the American University of Beirut and Spencer Wells were published in the October 2004 issue of National Geographic. One of its conclusions is that "more than half of the Y-Chromosome lineages that we see in today's Maltese population could have come in with the Phoenicians."[28]

Human migrationEdit

Main article: Human migration

Genealogical DNA testing methods are in use on a longer time scale to trace human migratory patterns. For example, they determined when the first humans came to North America and what path they followed.

For several years, researchers and laboratories from around the world sampled indigenous populations from around the globe in an effort to map historical human migration patterns. The National Geographic Society's Genographic Project aims to map historical human migration patterns by collecting and analyzing DNA samples from over 100,000 people across five continents. The DNA Clans Genetic Ancestry Analysis measures a person's precise genetic connections to indigenous ethnic groups from around the world.[29]

See alsoEdit

ReferencesEdit

  1. ^ Darwin, George H. (Sep 1875). "Note on the Marriages of First Cousins". Journal of the Statistical Society of London 38 (3): 344–348. doi:10.2307/2338771. 
  2. ^ Klyosov, Anatole. "DNA Genealogy, Mutation Rates, and Some Historical Evidences Written in Y-Chromosome. I. Basic Principles and the Method". Russian Peoceedings in Nature. 
  3. ^ Skorecki, Karl; Selig, Sara; Blazer, Shraga; Bradman, Robert; Bradman, Neil; Waburton, P. J.; Ismajlowicz, Monica; Hammer, Michael F. (1 January 1997). "Y chromosomes of Jewish priests". Nature 385 (6611): 32. doi:10.1038/385032a0. PMID 8985243. 
  4. ^ Slavery at Jefferson's Monticello: The Paradox of Liberty, 27 January 2012 – 14 October 2012, Smithsonian Institution, accessed 23 March 2012. Quote: "The [DNA test results show a genetic link between the Jefferson and Hemings descendants: A man with the Jefferson Y chromosome fathered Eston Hemings (born 1808). While there were other adult males with the Jefferson Y chromosome living in Virginia at that time, most historians now believe that the documentary and genetic evidence, considered together, strongly support the conclusion that [Thomas] Jefferson was the father of Sally Hemings's children."
  5. ^ Sykes, Bryan; Irven, Catherine (2000). "Surnames and the Y Chromosome". The American Journal of Human Genetics 66 (4): 1417. doi:10.1086/302850. 
  6. ^ "CMMG alum launches multi-million dollar genetic testing company - Alum notes" 17 (2). Wayne State University, School of Medicine's alumni journal. Spring 2006. p. 1. Retrieved 24 Jan 2013. 
  7. ^ a b "How Big Is the Genetic Genealogy Market?". The Genetic Genealogist. Retrieved 19 Feb 2009. 
  8. ^ "Ancestry.com Launches new AncestryDNA Service: The Next Generation of DNA Science Poised to Enrich Family History Research" (Press release). Retrieved 1 July 2013. 
  9. ^ Belli, Anne (January 18, 2005). "Moneymakers: Bennett Greenspan". Houston Chronicle. Retrieved June 14, 2013. "Years of researching his family tree through records and documents revealed roots in Argentina, but he ran out of leads looking for his maternal great-grandfather. After hearing about new genetic testing at the University of Arizona, he persuaded a scientist there to test DNA samples from a known cousin in California and a suspected distant cousin in Buenos Aires. It was a match. But the real find was the idea for Family Tree DNA, which the former film salesman launched in early 2000 to provide the same kind of service for others searching for their ancestors." 
  10. ^ "National Genealogical Society Quarterly" 93 (1–4). National Genealogical Society. 2005. p. 248. "Businessman Bennett Greenspan hoped that the approach used in the Jefferson and Cohen research would help family historians. After reaching a brick wall on his mother's surname, Nitz, he discovered and Argentine researching the same surname. Greenspan enlisted the help of a male Nitz cousin. A scientist involved in the original Cohen investigation tested the Argentine's and Greenspan's cousin's Y chromosomes. Their haplotypes matched perfectly." 
  11. ^ Lomax, John Nova (April 14, 2005). "Who's Your Daddy?". Houston Press. Retrieved June 14, 2013. "A real estate developer and entrepreneur, Greenspan has been interested in genealogy since his preteen days." 
  12. ^ Capper, Russ (November 15, 2008). "Bennett Greenspan of FamilyTreeDNA.com". The BusinessMakers Radio Show. Retrieved June 14, 2013. 
  13. ^ Dardashti, Schelly Talalay (March 30, 2008). "When oral history meets genetics". The Jerusalem Post. Retrieved June 14, 2013. "Greenspan, born and raised in Omaha, Nebraska, has been interested in genealogy from a very young age; he drew his first family tree at age 11." 
  14. ^ Gibbens, Pam (April 2006). "Talk of The Town – At Familytree DNA, it's all Relative". Greater Houston Weekly / Houston Chronicle. Retrieved February 15, 2012. 
  15. ^ Bradford, Nicole (24 Feb 2008). "Riding the 'genetic revolution'". Houston Business Journal. Retrieved 19 June 2013. 
  16. ^ Jobling, Mark A.; Tyler-Smith, Chris (2003). "The human Y chromosome: An evolutionary marker comes of age". Nature Reviews Genetics 4 (8): 598–612. doi:10.1038/nrg1124. PMID 12897772. 
  17. ^ Deboeck, Guido. "Genetic Genealogy Becomes Mainstream". BellaOnline. Retrieved 19 Feb 2009. 
  18. ^ "The Genographic Project: A Landmark Study of the Human Journey". National Geographic. Retrieved 19 Feb 2009. 
  19. ^ a b Redmonds, George; King, Turi; Hey, David (2011). Surnames, DNA, and Family History. Oxford: Oxford University Press. p. 196. ISBN 9780199582648. "The growth of interest in genetic genealogy has inspired a group of individuals outside the academic area who are passionate about the subject and who have an impressive grasp of the research issues. Two focal points for this group are the International Society of Genetic Genealogy and the Journal of Genetic Genealogy. The ISOGG is a non-profit, non-commercial organization that provides resources and maintains one of the most up-to-date, if not completely academically verified, phylogenetic trees of Y chromosome haplogroups." 
  20. ^ "The International Society of Genetic Genealogy". Retrieved July 1, 2013. 
  21. ^ a b King, TE; Jobling, MA (2009). "What's in a name? Y chromosomes, surnames and the genetic genealogy revolution". Trends in Genetics 25 (8): 351–360. doi:10.1016/j.tig.2009.06.003. PMID 19665817. 
  22. ^ International Society of Genetic Genealogy (2006). "Y-DNA Haplogroup Tree 2006, Version: 1.24, Date: 7 June 2007". Retrieved 1 July 2013. 
  23. ^ Athey, Whit (2008). "Editor's Corner: A New Y-Chromosome Phylogenetic Tree". Journal of Genetic Genealogy 4 (1): i–ii. Retrieved July 8, 2013. "Meanwhile, new SNPs are being announced or published almost every month. ISOGG’s role will be to maintain a tree that is as up-to-date as possible, allowing us to see where each new SNP fits in." 
  24. ^ van Holst Pellekaan, Sheila (2013). "Genetic evidence for the colonization of Australia". Quaternary International 285: 44–56. doi:10.1016/j.quaint.2011.04.014. 
  25. ^ Family Tree DNA Editorial Team (2013). "Understanding Results: mtDNA (mitochondrial DNA)". Gene by Gene. Retrieved 1 July 2013. 
  26. ^ Family Tree DNA Editorial Team (2013). "Understanding Results: Y-DNA Short Tandem Repeat (STR)". Gene by Gene. Retrieved 1 July 2013. 
  27. ^ Family Tree DNA Editorial Team (2013). "Understanding Results: Y-DNA Single Nucleotide Polymorphism (SNP)". Gene by Gene. Retrieved 1 July 2013. 
  28. ^ Franklin-Barbajosa, Cassandra (Oct 2004). "In the Wake of the Phoenicians: DNA study reveals a Phoenician-Maltese link". National Geographic Online. Retrieved 19 Feb 2009. 
  29. ^ "DNA Clans (Y-Clan) - DNA Ancestry Analysis". Genebase. Retrieved 19 Feb 2009. 

Further readingEdit

Books

  • Carmichael, Terrence; Alexander Ivanof Kuklin; Ed Grotjan (2000). How to DNA Test Our Family Relationships (in English). Mountain View, CA: AceN Press. ISBN 978-0-9664027-1-1.  edit Early book on adoptions, paternity and other relationship testing. Carmichael is a founder of GeneTree.
  • Cavalli-Sforza, Luigi Luca; Paolo Menozzi; Alberto Piazza (1994). The History and Geography of Human Genes (in English). Princeton, N.J.: Princeton University Press. ISBN 978-0-691-08750-4.  edit
  • Cavalli-Sforza, Luigi L.; Francesco Cavalli-Sforza; Heather Mimnaugh; Lynn Parker (1996). The Great Human Diasporas : The History of Diversity and Evolution (in English). Reading, MA: Addison-Wesley. ISBN 978-0-201-44231-1.  edit
  • Fitzpatrick, Colleen; Andrew Yeiser (2005). DNA and Genealogy (in English). Fountain Valley, CA: Rice Book Press. ISBN 978-0-9767160-1-3.  edit
  • Gamble, Clive (1996). Timewalkers : The Prehistory of Global Colonization (in English). Cambridge, MA: Harvard University Press. ISBN 978-0-674-89203-3.  edit
  • Jobling, Mark; Matthew Hurles; Chris Tyler-Smith (2003). Human Evolutionary Genetics : Origins, Peoples and Disease (in English). New York, NY: Garland Science. ISBN 978-0-8153-4185-7.  edit
  • Olson, Steve (2003). Mapping Human History : Genes, Race, and Our Common Origins (in English). Boston, MA: Houghton Mifflin. ISBN 978-0-618-35210-4.  edit Survey of major populations.
  • Oppenheimer, Stephen (2003). The Real Eve : Modern Man's Journey Out of Africa (in English). New York, NY: Carroll & Graf. ISBN 978-0-7867-1192-5.  edit
  • Smolenyak, Megan; Ann Turner (2004). Trace Your Roots with DNA : Using Genetic Tests to Explore Your Family Tree (in English). Emmaus, PA; Rodale, NY: Distributed to the trade by Holtzbrinck Publishers. ISBN 978-1-59486-006-5.  edit Out of date but still worth reading.
  • Pomery, Chris; Steve Jones (2004). DNA and Family History : How Genetic Testing Can Advance Your Genealogical Research (in English). Toronto, Ontario, Canada: Dundurn Group. ISBN 978-1-5500-2536-1.  edit Early guide for do-it-yourself genealogists.
  • Pomery, Chris (2007). Family History in the Genes : Trace Your DNA and Grow Your Family Tree (in English). Kew, UK: National Archives. ISBN 978-1-905615-12-4.  edit
  • Shawker, Thomas H. (2004). Unlocking Your Genetic History : A Step-by-Step Guide to Discovering Your Family's Medical and Genetic Heritage (in English). Nashville, TN: Rutledge Hill Press. ISBN 978-1-4016-0144-7.  edit Guide to the subject of family medical history and genetic diseases.
  • Sykes, Bryan (2002). The Seven Daughters of Eve : The Science That Reveals Our Genetic Ancestry (in English). New York, NY: Norton. ISBN 978-0-393-32314-6.  edit Names the founders of Europe’s major female haplogroups Helena, Jasmine, Katrine, Tara, Velda, Xenia, and Ursula.
  • Sykes, Bryan (2004). Adam's Curse : A Future Without Men (in English). New York, NY: W.W. Norton. ISBN 978-0-393-05896-3.  edit
  • Tagliaferro, Linda; Mark Vincent Bloom (1999). Complete Idiot's Guide to Decoding Your Genes (in English). New York, NY: Alpha Books. ISBN 978-0-02-863586-6.  edit
  • Wells, Spencer (2004). The Journey of Man : A Genetic Odyssey (in English). New York, NY: Random House Trade Paperbacks. ISBN 978-0-8129-7146-0.  edit

Documentaries

  • PBS (2003). The Journey of Man DVD. Broadcast aired in January 2003, Spencer Wells, host.

Journals

External links and resourcesEdit

ArticlesEdit

MapsEdit

NewsEdit

  • MSNBC – Genetic Genealogy Front Page