Haplogroup T (mtDNA)

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Haplogroup T
Possible time of origin 25,149 ± 4,668 Years Before Present
Possible place of origin Mesopotamia / Fertile Crescent (modern Syria / Turkey)
Ancestor J'T
Descendants T1 and T2
Defining mutations G709A, G1888A, A4917G, G8697A, T10463C, G13368A, G14905A, A15607G, G15928A, C16294T

In human population genetics, mitochondrial (mtDNA) haplogroups define the major lineages of direct maternal (female) lines back to a shared common ancestor in Africa. In human genetics, Haplogroup T is a predominantly Eurasian lineage.

Origins[edit]

Mitochondrial (mtDNA) Haplogroup T derives from the haplogroup J'T that also gave rise to haplogroup J. It is thought to have emanated from the Middle East (Bermisheva 2002).

Distribution[edit]

Haplogroup T is a widespread haplogroup throughout Western and Central Eurasia with varying degrees of prevalence and certainly might have been present in other groups from the surrounding areas. T is found in approximately 10% of native Europeans.[1][2] It is also common among modern day Iranians. Based on a sample of over 400 modern day Iranians (Kivisild and Metspalu 2003), the T haplogroup represents roughly 8.3% of the population (about 1 out of 12 individuals), with the more specific T1 subtype constituting roughly half of those. Furthermore, the specific subtype T1 tends to be found further east and is common in Central Asian and modern Turkic populations (Lalueza-Fox 2004), who inhabit much of the same territory as the ancient Saka, Sarmatian, Andronovo, and other putative Iranian peoples of the 2nd and 1st millennia BC. Lalueza-Fox et al. (2004) also found several T and T1 sequences in ancient burials, including kurgans, in the Kazakh steppe between the 14th-10th centuries BC, as well as later into the 1st millenia BC. These coincide with the latter part of the Andronovo period and the Saka period in the region.[3]

Haplogroup T is currently found with high concentrations around the eastern Baltic Sea.

The geographic distribution within subclade T2 varies greatly with the ratio of subhaplogroup T2e to T2b reported to vary 40-fold across examined populations from a low in Britain and Ireland, to a high in Saudi Arabia (Bedford 2012). Within subhaplogroup T2e, a very rare motif is identified among Sephardic Jews of Turkey and Bulgaria and suspected conversos from the New World (Bedford 2012). Found in Svan population from Caucasus(Georgia) T* 10,4% and T1 4,2%. T1a1a1 is particularly common in countries with high levels of Y-haplogroup R1a, such as Central and Northeast Europe, but also everywhere in Central Asia and deep into North Asia, as far east as Mongolia.

Archeology[edit]

Wilde et al. (2014) tested mtDNA samples from the Yamna culture, the presumed homeland of Proto-Indo-European speakers, and found T2a1b in the Middle Volga region and Bulgaria, and T1a both in central Ukraine and the Middle Volga. The frequency of T1a and T2 in Yamna samples were each 14.5%, a percentage higher than in any country today and only found in similarly high frequencies among the Udmurts of the Volga-Ural region.[4]

Africa[edit]

Haplogroup T is uncommon in Africa and is absent from most populations there. Its highest frequencies are in two Semitic speaking peoples: the Amhara and the Tigrai (Kivisild 2004).

Population Location Language Family N Frequency Source
Amhara Ethiopia Afro-Asiatic > Semitic 5/120 4.17% Kivisild 2004
Beta Israel Ethiopia Afro-Asiatic > Cushitic 0/29 0.00% Behar 2008a
Dawro K. Ethiopia Afro-Asiatic > Omotic 2/137 1.46% Castrì 2008 and Boattini 2013
Ethiopia Ethiopia Undetermined 2/77 2.60% Soares 2011
Ethiopian Jew Ethiopia Afro-Asiatic > Cushitic 0/41 0.00% Non 2011
Gurage Ethiopia Afro-Asiatic > Semitic 0/21 0.00% Kivisild 2004
Hamer Ethiopia Afro-Asiatic > Omotic 0/11 0.00% Castrì 2008 and Boattini 2013
Ongota Ethiopia Afro-Asiatic > Cushitic 0/19 0.00% Castrì 2008 and Boattini 2013
Oromo Ethiopia Afro-Asiatic > Cushitic 0/33 0.00% Kivisild 2004
Tigrai Ethiopia Afro-Asiatic > Semitic 3/44 6.82% Kivisild 2004
Daasanach Kenya Afro-Asiatic > Cushitic 0/49 0.00% Poloni 2009
Elmolo Kenya Afro-Asiatic > Cushitic 0/52 0.00% Castrì 2008 and Boattini 2013
Kikuyu Kenya Niger-Congo 0/25 0.00% Watson 1997
Luo Kenya Nilo-Saharan 0/49 0.00% Castrì 2008 and Boattini 2013
Maasai Kenya Nilo-Saharan 0/81 0.00% Castrì 2008 and Boattini 2013
Nairobi Kenya Niger-Congo 0/100 0.00% Brandstatter 2004
Nyangatom Kenya Nilo-Saharan 0/112 0.00% Poloni 2009
Rendille Kenya Afro-Asiatic > Cushitic 0/17 0.00% Castrì 2008 and Boattini 2013
Samburu Kenya Nilo-Saharan 0/35 0.00% Castrì 2008 and Boattini 2013
Turkana Kenya Nilo-Saharan 0/51 0.00% Castrì 2008 and Boattini 2013
Turkana Kenya Nilo-Saharan 0/47 0.00% Poloni 2009 and Watson 1997
Hutu Rwanda Niger-Congo 0/42 0.00% Castrì 2009
Somali Somalia Afro-Asiatic > Cushitic 2/163 1.23% Soares 2011 and Watson 1997
Dinka Sudan Nilo-Saharan 0/46 0.00% Krings 1999
Sudan Sudan Undetermined 3/102 2.94% Soares 2011
Burunge Tanzania Afro-Asiatic > Cushitic 0/38 0.00% Tishkoff 2007
Datoga Tanzania Nilo-Saharan 1/57 1.75% Tishkoff 2007 and Knight 2003
Iraqw Tanzania Afro-Asiatic > Cushitic 0/12 0.00% Knight 2003
Sukuma Tanzania Niger-Congo 0/32 0.00% Tishkoff 2007 and Knight 2003
Turu Tanzania Niger-Congo 0/29 0.00% Tishkoff 2007
Yemeni Yemen Afro-Asiatic > Semitic 1/114 0.88% Kivisild 2004

Asia[edit]

Europe[edit]

Subclades[edit]

Tree[edit]

This phylogenetic tree of haplogroup I subclades is based on the paper (van Oven 2008) and subsequent published research (Behar 2012b). For brevity, only the first three levels of subclades (branches) are shown.

  • T
    • T1
      • T1a
        • T1a1
      • T1b
    • T2
      • T2a
        • T2a1
      • T2b
        • T2b1
        • T2b2
        • T2b3
        • T2b4
        • T2b5
        • T2b6
      • T2c
        • T2c1
      • T2d
      • T2e
        • T2e2
      • T2f
        • T2f1
      • T2g

Health Issues[edit]

One study has shown Haplogroup T to be associated with increased risk for coronary artery disease (Sanger 2007). However, some studies have also shown that people of Haplogroup T are less prone to diabetes (Chinnery 2007 and González 2012).

A few tentative medical studies have demonstrated that Haplogroup T may offer some resistance to both Parkinson's disease and Alzheimer's disease.[Footnote 1]

Certain medical studies had shown mitochondrial Haplogroup T to be associated with reduced sperm motility in males, although these results have been challenged (Mishmar 2002). According to the Departamento de Bioquimica y Biologica Molecular y Celular, Universidad de Zaragoza, Haplogroup T represents a weak genetic background that can predispose to asthenozoospermia (Ruiz-Pesini 2000). However, these findings have been disputed due to a small sample size in the study (Mishmar 2002).

Popular Culture[edit]

Popular Science[edit]

In his popular book The Seven Daughters of Eve, Bryan Sykes, who is in Haplogroup T, named the originator of this group "Tara," which means rocky hill in Gaelic. Sykes believes that: "Tara herself lived 17,000 years ago in the northwest of Italy among the hills of Tuscany and along the estuary of the river Arno" (Sykes 2002).

Famous Members[edit]

Nicholas II of Russia[edit]

The last Russian Tsar, Nicholas II, has been shown to be of Haplogroup T, specifically subclade T2 (Ivanov 1996). Assuming all relevant pedigrees are correct, this includes all female-line descendants of his female line ancestor Barbara of Celje (1390-1451), wife of Sigismund, Holy Roman Emperor. This includes a great number of European nobles, including George I of Great Britain and Frederick William I of Prussia (through the Electress Sophia of Hanover), Charles I of England, George III of the United Kingdom, George V of the United Kingdom, Charles X Gustav of Sweden, Gustavus Adolphus of Sweden, Maurice of Nassau, Prince of Orange, Olav V of Norway, and George I of Greece. Many European royals have been found to be of this mtDNA Haplogroup, in addition to Haplogroup H (mtDNA).[citation needed]

See also[edit]

Genetics[edit]

Backbone mtDNA Tree[edit]

Evolutionary tree of human mitochondrial DNA (mtDNA) haplogroups

  Mitochondrial Eve (L)    
L0 L1–6
L1 L2 L3   L4 L5 L6
  M N  
CZ D E G Q   A S   R   I W X Y
C Z B F R0   pre-JT P  U
HV JT K
H V J T

References[edit]

Footnotes[edit]

  1. ^ Phylogenetic Networks for the Human mtDNA Haplogroup T, David A. Pike, "Elsewhere it has been reported that membership in haplogroup T may offer some protection against Alzheimer Disease (Chagnon et al. 1999; Herrnstadt et al. 2002) and also Parkinson's Disease (Pyle et al. 2005), but the cautionary words of Pereira et al. suggest that further studies may be necessary before reaching firm conclusions."

Citations[edit]

  1. ^ Bryan Sykes (2001). The Seven Daughters of Eve. London; New York: Bantam Press. ISBN 0393020185. 
  2. ^ "Maternal Ancestry". Oxford Ancestors. Retrieved 7 February 2013. 
  3. ^ Bennett, Casey and Frederika A. Kaestle (2010) “Investigation of Ancient DNA from Western Siberia and the Sargat Culture.” Human Biology. 82(2): 143-156.
  4. ^ Wilde et al. 2014. 2Direct evidence for positive selection of skin, hair, and eye pigmentation in Europeans during the last 5,000 y". PNAS vol. 111 no. 13 > doi: 10.1073/pnas.1316513111

Works Cited[edit]

Books[edit]

  • Sykes, Bryan (2002). The Seven Daughters of Eve: The Science That Reveals Our Genetic Ancestry. W. W. Norton & Company. ISBN 9780393323146. 

Journals[edit]

Websites[edit]

Further reading[edit]

External links[edit]