Post by Διαμονδ on Dec 10, 2017 22:49:40 GMT
Haplogroup T is a human mitochondrial DNA (mtDNA) haplogroup. It is believed to have originated around 25,100 years ago in the Near East.
Origins
Mitochondrial clade T derives from the haplogroup JT, which also gave rise to the mtDNA haplogroup J. The T maternal clade is thought to have emanated from the Near East (Bermisheva 2002).
Distribution
Projected spatial frequency distribution for haplogroup T.
The basal haplogroup T* is found among Algerians in Oran (1.67%) and Reguibate Sahrawi (0.93%). It is also distributed among the Soqotri (1.2%).
Haplogroup T is present at low frequencies haplogroup throughout Western and Central Asia and Europe, 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.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 millennia BC. These coincide with the latter part of the Andronovo period and the Saka period in the region.
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. The clade is also found everywhere in Central Asia and deep into North Asia, as far east as Mongolia.
T2c and T2d appear to have a Near Eastern origin around the time of the Last Glacial Maximum and more recent dispersals into Europe. Most of T2c comprises haplogroup T2c1. Apart from a peak in Cyprus, T2c1 is most common in the Gulf region but is also found in the Levant and in Mediterranean Europe, with a more far-flung distribution at very low levels.
T2 is also found among the Soqotri (7.7%).
Archaeology
Wilde et al. (2014) tested mtDNA samples from the Yamna culture, the presumed homeland of Proto-Indo-European speakers. They 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.
Haplogroup T has also been found among Iberomaurusian specimens dating from the Epipaleolithic at the Afalou prehistoric site in Algeria. One ancient individual carried the T2b subclade (1/9; 11%). Additionally, haplogroup T has been observed among ancient Egyptian mummies excavated at the Abusir el-Meleq archaeological site in Middle Egypt, which date from the Pre-Ptolemaic/late New Kingdom (T1, T2), Ptolemaic (T1, T2), and Roman (undifferentiated T, T1) periods. Fossils excavated at the Late Neolithic site of Kelif el Boroud in Morocco, which have been dated to around 3,000 BCE, have also been observed to carry the T2 subclade. Additionally, haplogroup T has been observed in ancient Guanche fossils excavated in Gran Canaria and Tenerife on the Canary Islands, which have been radiocarbon-dated to between the 7th and 11th centuries CE. The clade-bearing individuals were inhumed at the Tenerife site, with one specimen found to belong to the T2c1d2 subclade (1/7; 14%).
Origins
Mitochondrial clade T derives from the haplogroup JT, which also gave rise to the mtDNA haplogroup J. The T maternal clade is thought to have emanated from the Near East (Bermisheva 2002).
Distribution
Projected spatial frequency distribution for haplogroup T.
The basal haplogroup T* is found among Algerians in Oran (1.67%) and Reguibate Sahrawi (0.93%). It is also distributed among the Soqotri (1.2%).
Haplogroup T is present at low frequencies haplogroup throughout Western and Central Asia and Europe, 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.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 millennia BC. These coincide with the latter part of the Andronovo period and the Saka period in the region.
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. The clade is also found everywhere in Central Asia and deep into North Asia, as far east as Mongolia.
T2c and T2d appear to have a Near Eastern origin around the time of the Last Glacial Maximum and more recent dispersals into Europe. Most of T2c comprises haplogroup T2c1. Apart from a peak in Cyprus, T2c1 is most common in the Gulf region but is also found in the Levant and in Mediterranean Europe, with a more far-flung distribution at very low levels.
T2 is also found among the Soqotri (7.7%).
Archaeology
Wilde et al. (2014) tested mtDNA samples from the Yamna culture, the presumed homeland of Proto-Indo-European speakers. They 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.
Haplogroup T has also been found among Iberomaurusian specimens dating from the Epipaleolithic at the Afalou prehistoric site in Algeria. One ancient individual carried the T2b subclade (1/9; 11%). Additionally, haplogroup T has been observed among ancient Egyptian mummies excavated at the Abusir el-Meleq archaeological site in Middle Egypt, which date from the Pre-Ptolemaic/late New Kingdom (T1, T2), Ptolemaic (T1, T2), and Roman (undifferentiated T, T1) periods. Fossils excavated at the Late Neolithic site of Kelif el Boroud in Morocco, which have been dated to around 3,000 BCE, have also been observed to carry the T2 subclade. Additionally, haplogroup T has been observed in ancient Guanche fossils excavated in Gran Canaria and Tenerife on the Canary Islands, which have been radiocarbon-dated to between the 7th and 11th centuries CE. The clade-bearing individuals were inhumed at the Tenerife site, with one specimen found to belong to the T2c1d2 subclade (1/7; 14%).
