Haplogroup L-M20 is a human Y-DNA haplogroup, which is defined by SNPs M11, M20, M61 and M185. As a secondary descendant of haplogroup K and a primary branch of haplogroup LT, haplogroup L currently has the alternative phylogenetic name of K1a, and is a sibling of haplogroup T (a.k.a. K1b).
The presence of L-M20 has been observed at varying levels throughout South Asia, peaking in populations native to southern Pakistan (28%),[3] Northern Afghanistan (25%),[4] and Southern India (19%).[5] The clade also occurs in Tajikistan and Anatolia, as well as at lower frequencies in Iran. It has also been present for millennia at very low levels in the Caucasus, Europe and Central Asia. The subclade L2 (L-L595) has been found in Europe and Western Asia, but is extremely rare.
Phylogenetic tree
There are several confirmed and proposed phylogenetic trees available for haplogroup L-M20. The scientifically accepted one is the Y-Chromosome Consortium (YCC) one published in Karafet 2008 and subsequently updated. A draft tree that shows emerging science is provided by Thomas Krahn at the Genomic Research Center in Houston, Texas.[web 1] The International Society of Genetic Genealogy (ISOGG) also provides an amateur tree.
This section needs expansion. You can help by adding to it. (January 2013)
This is Thomas Krahn at the Genomic Research Center's Draft tree Proposed Tree for haplogroup L-M20:[web 1]
L-M20 is a descendant of Haplogroup LT,[6][7] which is a descendant of haplogroup K-M9.[8][7] According to Dr. Spencer Wells, L-M20 originated in the Eurasian K-M9 clan that migrated eastwards from the Middle East, and later southwards from the Pamir Knot into present-day Pakistan and India.[9][10] These people arrived in India approximately 30,000 years ago.[9][10] Hence, it is hypothesized that the first bearer of M20 marker was born either in India or the Middle East.[9] Other studies have proposed either a West Asian or South Asian origin for L-M20 and associated its expansion in the Indus valley to Neolithic farmers.[11][12][13][14][15][16] Genetic studies suggest that L-M20 may be one of the haplogroups of the original creators of the Indus Valley Civilisation.[3][17][15] McElreavy and Quintana-Murci, writing on the Indus Valley Civilisation, state that
One Y-chromosome haplogroup (L-M20) has a high mean frequency of 14% in Pakistan and so differs from all other haplogroups in its frequency distribution. L-M20 is also observed, although at lower frequencies, in neighbouring countries, such as India, Tajikistan, Uzbekistan and Russia. Both the frequency distribution and estimated expansion time (~7,000 YBP) of this lineage suggest that its spread in the Indus Valley may be associated with the expansion of local farming groups during the Neolithic period.[15]
Sengupta et al. (2006) observed three subbranches of haplogroup L: L1-M76 (L1a1), L2-M317 (L1b) and L3-M357 (L1a2), with distinctive geographic affiliations.[5] Almost all Indian members of haplogroup L are L1 derived, with L3-M357 occurring only sporadically (0.4%).[18][19] Conversely in Pakistan, L3-M357 subclade account for 86% of L-M20 chromosomes and reaches an intermediate frequency of 6.8%, overall.[20] L1-M76 occurs at a frequency of 7.5% in India and 5.1% in Pakistan, exhibiting peak variance distribution in the Maharashtra region in coastal western India.[21]
Geographical distribution
In India, L-M20 has a higher frequency among Dravidian castes, but is somewhat rarer in Indo-Aryan castes.[5] In Pakistan, it has a frequency of about 28% in the southern regions including southern Baluchistan, from where the agricultural creators of the Indus valley civilization emerged .[22]
Preliminary evidence gleaned from non-scientific sources, such as individuals who have had their Y-chromosomes tested by commercial labs,[web 2] suggests that most European examples of Haplogroup L-M20 might belong to the subclade L2-M317, which is, among South Asian populations, generally the rarest of the subclades of Haplogroup L.[web 2]
South Asia
India
It has higher frequency among Dravidian castes (ca. 17-19%) but is somewhat rarer in Indo-Aryan castes (ca. 5-6%).[5] The presence of haplogroup L-M20 is quite rare among tribal groups (ca. 5,6-7%) (Cordaux 2004, Sengupta 2006, and Thamseem 2006). However, the Korova tribe of Uttara Kannada in which L-M11 occurs at 68% is an exception.[23]
L1a and L1c-M357 are found at 24% among Balochis, L1a and L1c are found at 8% among the Dravidian-speaking Brahui, L1c is found at 25% among Kalash, L1c is found at 15% among Burusho, L1a-M76 and L1b-M317 are found at 2% among the Makranis and L1c is found at 3.6% of Sindhis according to Julie di Cristofaro et al. 2013.[32] L-M20 is found at 17.78% among the Parsis.[11] L3a is found at 23% among the Nuristanis in both Pakistan and Afghanistan.[33]
54.9% (42/71) L in Priest Zoroastrian Parsis 22.2% L1b and L1c in South Iran (2/9) 8% to 16% L2-L595, L1a, L1b and L1c of Kurds in Kordestan (2-4/25) 9.1% L-M20 (7/77) of Persians in Eastern Iran 3.4% L-M76 (4/117) and 2.6% L-M317 (3/117) for a total of 6.0% (7/117) haplogroup L-M20 in Southern Iran 3.0% (1/33) L-M357 in Northern Iran 4.2% L1c-M357 of Azeris in East Azeris (1/21) 4.8% L1a and L1b of Persians in Esfahan (2/42)
A study on the Pashtun male lineages in Afghanistan, found that Haplogroup L-M20, with an overall frequency of 9.5%, is the second most abundant male lineage among them.[35] It exhibits substantial disparity in its distribution on either side of the Hindu Kush range, with 25% of the northern Afghan Pashtuns belonging to this lineage, compared with only 4.8% of males from the south.[35] Specifically, paragroup L3*-M357 accounts for the majority of the L-M20 chromosomes among Afghan Pashtuns in both the north (20.5%) and south (4.1%).[35] An earlier study involving a lesser number of samples had reported that L1c comprises 12.24% of the Afghan Pashtun male lineages.[36][37] L1c is also found at 7.69% among the Balochs of Afghanistan.[36] However L1a-M76 occurs in a much more higher frequency among the Balochs (20[37] to 61.54%),[37] and is found at lower levels in Kyrgyz, Tajik, Uzbek and Turkmen populations.[37]
Researchers studying samples of Y-DNA from populations of East Asia have rarely tested their samples for any of the mutations that define Haplogroup L. However, mutations for Haplogroup L have been tested and detected in samples of Balinese (13/641 = 2.0% L-M20), Han Chinese (1/57 = 1.8%),[39]Dolgans from Sakha and Taymyr (1/67 = 1.5% L-M20) and Koreans (3/506 = 0.6% L-M20).[40][41][42]
Europe
An article by O. Semino et al. published in the journal Science (Volume 290, 10 November 2000) reported the detection of the M11-G mutation, which is one of the mutations that defines Haplogroup L, in approximately 1% to 3% of samples from Georgia, Greece, Hungary, Calabria (Italy), and Andalusia (Spain). The sizes of the samples analyzed in this study were generally quite small, so it is possible that the actual frequency of Haplogroup L-M20 among Mediterranean European populations may be slightly lower or higher than that reported by Semino et al., but there seems to be no study to date that has described more precisely the distribution of Haplogroup L-M20 in Southwest Asia and Europe.
20% (2/10) of Georgians in Gali, 14.3% (2/14) of Georgians in Chokhatauri, 12.5% (2/16) of Georgians in Martvili, 11.8% (2/17) of Georgians in Abasha, 11.1% (2/18) of Georgians in Baghdati, 10% (1/10) of Georgians in Gardabani, 9.1% (1/11) of Georgians in Adigeni, 6.9% (2/29) of Georgians in Omalo, 5.9% (1/17) of Georgians in Gurjaani, 5.9% (1/17) of Georgians in Lentekhi and 1.5% (1/66) L-M357(xPK3) to 1.6% (1/63) L-M11
Researchers in 2013 studying the origins of the Lemba people - who are of paternal South Arabian ancestry - found that 13.8% of Lemba males carried the Y-DNA L-M20, specifically the subclade L-M349 making it the 4th most common lineage amongst them.[43] A Lemba sample from South Africa submitted to Familytreedna in 2023 was found to carry a yet unnamed L-M349 subclade of L-FT408126 which was closest to 2 samples from Iraq and Iran.[44]
Researchers also found traces of traces of L-M20 on the Swahili coast in Kenya amounting to 4.2% of the total population.
The L1 subclade is also found at low frequencies on the Comoros Islands.[45]
L1a1 (M27)
L-M27 is found in 14.5% of Indians and 15% of Sri Lankans, with a moderate distribution in other populations of Pakistan, southern Iran and Europe, but slightly higher Middle East Arab populations.[citation needed] There is a very minor presence among Siddi's (2%),[46] as well.
L-M317 has been found in Makranis (2/20 = 10%) in Pakistan, Iranians (3/186 = 1.6%), Pashtuns in Afghanistan
(1/87 = 1.1%), and Uzbeks in Afghanistan (1/127 = 0.79%).[37]
L1b1 (M349)
L-M349 is found in some Crimean Karaites who are Levites.[51] Some of L-M349's branches are found in West Asia, including L-Y31183 in Lebanon, L-Y31184 in Armenia, and L-Y130640 in Iraq, Iran, Yemen and South Africa. Others are found in Europe, such as L-PAGE116 in Italy, L-FT304386 in Slovenia, and L-FGC36841 in Moldova.[52] 13.8% of Lemba males carry L-M349 under the clade L-Y130640.[43] This percentage is most likely due to a founder effect in their population making them the only group on the African continent with any substantial proportion of L-M20.
L2 (L595)
L2-L595 is extremely rare, and has been identified by private testing in individuals from Europe and Western Asia.
Two confirmed L2-L595 individuals from Iran were reported in a 2020 study supplementary.[53] Possible but unconfirmed cases of L2 include 4% (1/25) L-M11(xM76, M27, M317, M357) in a sample of Iranians in Kordestan[37] and 2% (2/100) L-M20(xM27, M317, M357) in a sample of Shapsugs,[48] among other rare reported cases of L which don't fall into the common branches.
Three individuals from Maykop culture c. 3200 BCE were found to belong to haplogroup L2-L595.[58]
Three individuals who lived in the Chalcolithic era (c. 5700–6250 years BP), found in the Areni-1 ("Bird's Eye") cave in the South Caucasus mountains (present-day Vayots Dzor Province, Armenia), were also identified as belonging to haplogroup L1a. One individual's genome indicated that he had red hair and blue eyes. Their genetic data is listed in the table below.
Narasimhan et al. (2018) analyzed skeletons from the BMAC sites in Uzbekistan and identified 2 individuals as belonging to haplogroup L1a. One of these specimens was found in Bustan and the other in Sappali Tepe; both ascertained to be Bronze Age sites.[59]
Skourtanioti et al. (2020) analyzed skeletons from Alalakh and identified one individual (ALA084) c. 2006-1777 BC as belonging to haplogroup L-L595 (L2).[60] Ingman et al. (2021) analyzed more skeletons from Alalakh and identified another individual belonging to haplogroup L-M349 (L1b).[61]
Prior to 2002, there were in academic literature at least seven naming systems for the Y-Chromosome Phylogenetic tree. This led to considerable confusion. In 2002, the major research groups came together and formed the Y-Chromosome Consortium (YCC). They published a joint paper that created a single new tree that all agreed to use. Later, a group of citizen scientists with an interest in population genetics and genetic genealogy formed a working group to create an amateur tree aiming at being above all timely. The table below brings together all of these works at the point of the landmark 2002 YCC Tree. This allows a researcher reviewing older published literature to quickly move between nomenclatures.
This is the official scientific tree produced by the Y-Chromosome Consortium (YCC). The last major update was in 2008.[citation needed] Subsequent updates have been quarterly and biannual. The current version is a revision of the 2010 update.[65]
This section needs expansion. You can help by adding to it. (January 2013)
Original research publications
The following research teams per their publications were represented in the creation of the YCC Tree.
^Van Oven M, Van Geystelen A, Kayser M, Decorte R, Larmuseau HD (2014). "Seeing the wood for the trees: a minimal reference phylogeny for the human Y chromosome". Human Mutation. 35 (2): 187–91. doi:10.1002/humu.22468. PMID24166809. S2CID23291764.
^K-M2313*, which as yet has no phylogenetic name, has been documented in two living individuals, who have ethnic ties to India and South East Asia. In addition, K-Y28299, which appears to be a primary branch of K-M2313, has been found in three living individuals from India. See: Poznik op. cit.; YFull YTree v5.08, 2017, "K-M2335", and; PhyloTree, 2017, "Details of the Y-SNP markers included in the minimal Y tree" (Access date of these pages: 9 December 2017)
^ Haplogroup S, as of 2017, is also known as K2b1a. (Previously the name Haplogroup S was assigned to K2b1a4.)
^ Haplogroup M, as of 2017, is also known as K2b1b. (Previously the name Haplogroup M was assigned to K2b1d.)
^ abcWells S (20 November 2007). Deep Ancestry: The Landmark DNA Quest to Decipher Our Distant Past. National Geographic Books. pp. 161–162. ISBN978-1-4262-0211-7. This part of the M9 Eurasian clan migrated south once they reached the rugged and mountainous Pamir Knot region. The man who gave rise to marker M20 was possibly born in India or the Middle East. His ancestors arrived in India around 30,000 years ago and represent the earliest significant settlement of India.
^ abcMcElreavey K, Quintana-Murci L (2005). "A population genetics perspective of the Indus Valley through uniparentally-inherited markers". Annals of Human Biology. 32 (2): 154–162. doi:10.1080/03014460500076223. PMID16096211. S2CID109014.
^ abLiu SH, N, Yilihamu, R Bake (2018). "A study of genetic diversity of three isolated populations in Xinjiang using Y-SNP". Acta Anthropologica Sinica. 37 (1): 146–156.
^ abSoodyall H (October 2013). "Lemba origins revisited: tracing the ancestry of Y chromosomes in South African and Zimbabwean Lemba". South African Medical Journal = Suid-Afrikaanse Tydskrif vir Geneeskunde. 103 (12 Suppl 1): 1009–1013. doi:10.7196/SAMJ.7297 (inactive 10 November 2024). PMID24300649.{{cite journal}}: CS1 maint: DOI inactive as of November 2024 (link)
^ abcdVincenza Battaglia, Simona Fornarino, Nadia Al-Zahery, et al. (2009), "Y-chromosomal evidence of the cultural diffusion of agriculture in southeast Europe." European Journal of Human Genetics (2009) 17, 820–830; doi:10.1038/ejhg.2008.249; published online 24 December 2008.
^Chuan-Chao Wang, Sabine Reinhold, Alexey Kalmykov, Antje Wissgott, Guido Brandt, Choongwon Jeong, Olivia Cheronet, Matthew Ferry, Eadaoin Harney, Denise Keating, Swapan Mallick, Nadin Rohland, Kristin Stewardson, Anatoly R. Kantorovich, Vladimir E. Maslov, Vladimira G. Petrenko, Vladimir R. Erlikh, Biaslan Ch. Atabiev, Rabadan G. Magomedov, Philipp L. Kohl, Kurt W. Alt, Sandra L. Pichler, Claudia Gerling, Harald Meller, Benik Vardanyan, Larisa Yeganyan, Alexey D. Rezepkin, Dirk Mariaschk, Natalia Berezina, Julia Gresky, Katharina Fuchs, Corina Knipper, Stephan Schiffels, Elena Balanovska, Oleg Balanovsky, Iain Mathieson, Thomas Higham, Yakov B. Berezin, Alexandra Buzhilova, Viktor Trifonov, Ron Pinhasi, Andrej B. Belinskiy, David Reich, Svend Hansen, Johannes Krause, Wolfgang Haak
bioRxiv 322347; doi: https://doi.org/10.1101/322347
Now published in Nature Communications doi: 10.1038/s41467-018-08220-8
Beleza S, Gusmão L, Lopes A, Alves C, Gomes I, Giouzeli M, et al. (March 2006). "Micro-phylogeographic and demographic history of Portuguese male lineages". Annals of Human Genetics. 70 (Pt 2): 181–194. doi:10.1111/j.1529-8817.2005.00221.x. PMID16626329. S2CID4652154.
Boattini A, Castrì L, Sarno S, Useli A, Cioffi M, Sazzini M, et al. (March 2013). "mtDNA variation in East Africa unravels the history of Afro-Asiatic groups". American Journal of Physical Anthropology. 150 (3): 375–385. doi:10.1002/ajpa.22212. PMID23283748.
Di Giacomo F, Luca F, Anagnou N, Ciavarella G, Corbo RM, Cresta M, et al. (September 2003). "Clinal patterns of human Y chromosomal diversity in continental Italy and Greece are dominated by drift and founder effects". Molecular Phylogenetics and Evolution. 28 (3): 387–395. Bibcode:2003MolPE..28..387D. doi:10.1016/S1055-7903(03)00016-2. PMID12927125.
Larmuseau MH, Vanderheyden N, Jacobs M, Coomans M, Larno L, Decorte R (March 2011). "Micro-geographic distribution of Y-chromosomal variation in the central-western European region Brabant". Forensic Science International. Genetics. 5 (2): 95–99. doi:10.1016/j.fsigen.2010.08.020. PMID21036685.
Pichler I, Mueller JC, Stefanov SA, De Grandi A, Volpato CB, Pinggera GK, et al. (December 2009). "Genetic structure in contemporary South Tyrolean isolated populations revealed by analysis of Y-chromosome, mtDNA, and Alu polymorphisms. 2006". Human Biology. 81 (5–6): 875–898. doi:10.3378/027.081.0629. PMID20504204. S2CID46073270.
Scozzari R, Cruciani F, Pangrazio A, Santolamazza P, Vona G, Moral P, et al. (September 2001). "Human Y-chromosome variation in the western Mediterranean area: implications for the peopling of the region". Human Immunology. 62 (9): 871–884. CiteSeerX10.1.1.408.4857. doi:10.1016/S0198-8859(01)00286-5. PMID11543889.
Semino O, Passarino G, Oefner PJ, Lin AA, Arbuzova S, Beckman LE, et al. (November 2000). "The genetic legacy of Paleolithic Homo sapiens sapiens in extant Europeans: a Y chromosome perspective". Science. 290 (5494): 1155–1159. Bibcode:2000Sci...290.1155S. doi:10.1126/science.290.5494.1155. PMID11073453.
Tarkhnishvili D, Gavashelishvili A, Murtskhvaladze M, Gabelaia M, Tevzadze G (2014). "Human paternal lineages, languages, and environment in the Caucasus". Human Biology. 86 (2): 113–130. doi:10.3378/027.086.0205. PMID25397702. S2CID7733899.
Weale ME, Yepiskoposyan L, Jager RF, Hovhannisyan N, Khudoyan A, Burbage-Hall O, et al. (December 2001). "Armenian Y chromosome haplotypes reveal strong regional structure within a single ethno-national group". Human Genetics. 109 (6): 659–674. doi:10.1007/s00439-001-0627-9. PMID11810279. S2CID23113666.
Jobling MA, Tyler-Smith C (August 2000). "New uses for new haplotypes the human Y chromosome, disease and selection". Trends in Genetics. 16 (8): 356–362. doi:10.1016/S0168-9525(00)02057-6. PMID10904265.
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