Possible time of origin 25,000-30,000 years BP Ancestor LT | ||
 | ||
Defining mutations M11, M20, M61, M185, L656, L863, L878, L879 Highest frequencies South Asians, Burusho, Kalash, Pashtuns, Tamil Kallars, Afshar village, Raqqa, east Balochistan, northern Afghanistan, Fascia, Venetia, South Tyrol | ||
Haplogroup L-M20 is a human Y-DNA haplogroup, which is defined by SNPs M11, M20, M61 and M185. It is most commonly found in populations native to South Asia, especially Afghanistan, Pakistan and South India. The clade also occurs in Tajikistan and Anatolia, as well as at lower frequencies in Iran, Western Europe, Central Europe, Northeastern Europe, the Caucasus, Balkans and Central Asia. The subclade L2 (L-L595), while it is extremely rare, is seldom found outside Western Europe.
Contents
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. The International Society of Genetic Genealogy (ISOGG) also provides an amateur tree.
This is Thomas Krahn at the Genomic Research Center's Draft tree Proposed Tree for haplogroup L-M20:
Origins
L-M20 is a descendant of Haplogroup LT, which is a descendant of haplogroup K-M9. According to Spencer Wells, M20 migrated into India ca. 30,000 years ago. 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.
Sengupta et al. (2006) discovered three subbranches of haplogroup L: L1-M76 (L1a1), L2-M317 (L1b) and L3-M357 (L1a2). All three are found mostly in South Asia. According to Sengupta et al. (2006), the L-M20 subclade L-M76 (L1a1) "underwent early diversification in South India and subsequently expanded toward peripheral regions." They note that the frequency and microsatellite variance of L1 are highest in south India, the southwest and the west coast, proposing "a pattern of spread emanating from southern India." They further note that haplogroup L-M76 "is clearly predominant in Dravidian speakers," concluding that "our data provide overwhelming support for an Indian origin of Dravidian speakers."
Sengupta et al. (2006) further note that L3-M357 (L1a2) "occurs with an intermediate frequency in Pakistan (6.8%), [while] it is very rare in India (0.4%). Conversely, L1-M76 occurs at a frequency of 7.5% in India and 5.1% in Pakistan," which may be an indication that L-M20 originated in the northwestern part of South Asia.
Geographical distribution
In India, L-M20 has a higher frequency among Dravidian castes, but is somewhat rarer in Indo-Aryan castes. In Pakistan, it has highest frequency in Balochistan.
It has also been found at low frequencies among populations of Central Asia and South West Asia (including Arabia, Iraq, Syria, Turkey, Lebanon, Egypt, and Yemen) as well as in Southern Europe (especially areas adjoining the Mediterranean Sea).
Preliminary evidence gleaned from non-scientific sources, such as individuals who have had their Y-chromosomes tested by commercial labs, 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.
India
It has higher frequency among Dravidian castes (ca. 17-19%) but is somewhat rarer in Indo-Aryan castes (ca. 5-6%). It reaches up to 68% in some tribes and castes of Karnataka 38% in some castes and tribes of Gujarat and reaches up to 48% in some castes in Tamil Nadu. Earlier studies (e.g. Wells 2001) report a very high frequency (approaching 80%) of Haplogroup L-M20 in Tamil Nadu appear to have been due to extrapolation from data obtained from a sample of 84 Kallars, a Tamil-speaking higher ruler caste of Tamil Nadu, among whom 40 (approx. 48%) displayed the M20 mutation that defines Haplogroup L. The presence of haplogroup L-M20 is rare among tribal groups (ca. 5,6-7%) (Cordaux 2004, Sengupta 2006, and Thamseem 2006).
L-M20 was found 68% in the Korova tribe from Karnataka, 38% in the Bharwad caste from Junagarh district in Gujarat, 21% in Charan caste from Junagarh district in Gujarat and 17% in the Kare Vokkal tribe from Uttara Kannada in Karnataka.(Shah 2011) Also found at low frequency in other populations from Junagarh district and Uttara Kannada. It is found at 16.33% among the Gujar's of Jammu and Kashmir. It also occurs at 18.6% among the Konkanastha Brahmins of the Konkan region and at 15% among the Maratha's of Maharashtra. L-M20 is also found at 32.35% in the Vokkaligas and at 17.82% in the Lingayats of Karnataka. L-M20 is also found at 20.7% among the Ambalakarar, 16.7% among the Iyengar and 17.2% among the Iyer castes of Tamil Nadu. L-M11 is found in frequncies of 8-16% among Indian Jews. 2% of Siddis have also been reported with L-M11.(Shah 2011) Haplogroup L-M20 is currently present in the Indian population at an overall frequency of ca. 7-15%.
Pakistan
The greatest concentration of Haplogroup L-M20 is along the Indus River in Pakistan where the Indus Valley Civilization flourished during 3300–1300 BCE and mature period 2600–1900 BCE. L-M357 highest frequency and diversity is found in the Balochistan province at 28%. with a moderate distribution among the general Pakistani population at 11.6% (Firasat 2007)). Many of these are found in their Afghanistan counterparts as well, such as with the Pashtuns and Balochis. L-M357 is found frequently among Burusho (approx. 12% (Firasat 2007)) and Pashtuns (approx. 7% (Firasat 2007)),
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. L-M20 is found at 17.78% among the Parsis. L3a is found at 23% among the Nuristanis in both Pakistan and Afghanistan.
L-PK3 is found in approximately 23% of Kalash in northwest Pakistan(Firasat 2007).
Afghanistan
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. 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. 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%). An earlier study involving a lesser number of samples had reported that L1c comprises 12.24% of the Afghan Pashtun male lineages. L1c-M357 occurs significantly in the Burusho and Kalash(15% and 25%), as well. L1c is also found at 7.69% among the Balochs of Afghanistan. However L1a-M76 occurs in a much more higher frequency among the Balochs (20 to 61.54%), and is found at lower levels in Kyrgyz, Tajik, Uzbek and Turkmen populations.
Middle East and Anatolia
L-M20 was found in 51% of Syrians from Raqqa, a northern Syrian city in which its previous inhabitants have been wiped out by the Mongol genocides and repopulated in recent times by local Bedouin populations and Chechen war refugees from Russia (El-Sibai 2009). In a small sample of Israeli Druze haplogroup L-M20 was found in 7 out of 20 (35%). However, studies done on bigger samples showed that L-M20 averages 5% in Israeli Druze, 8% in Lebanese Druze, and it was not found in a sample of 59 Syrian Druze. Haplogroup L-M20 has been found in 2.0% (1/50) (Wells 2001) to 5.25% (48/914) of Lebanese (Zalloua 2008).
East Asia
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), Dolgans from Sakha and Taymyr (1/67 = 1.5% L-M20) and Koreans (3/506 = 0.6% L-M20).
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.
L1 (M295)
L-M295 is found from Western Europe to South Asia.
The L1 subclade is also found at low frequencies on the Comoros Islands.
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 European but more in Middle East Arab populations.Karafet 2016. There is a very minor presence among Siddi's(2%), as well.
L1a2 (M357)
L-M357 is found frequently among Burushos, Kalashas and Pashtuns, with a moderate distribution among other populations in Pakistan, Georgia, Chechens, northern Iran, India, the UAE, and Saudi Arabia.
L-PK3, which is downstream of L-M357, is found frequently among Kalash.
L1b (M317)
L-M317 is found at low frequency in Central Asia, Southwest Asia, and Central Europe.
L1b1 (M349)
L-M349 is principally found in Europe.
L2 (L595)
L-L595 is found only in Europe from Ireland, Iberian Peninsula and Sardinia to Eastern Europe and their highest frequency is found in Estonia, Scozzari 2001, Lappalainen 2008.
Ancient DNA
This haplogroup was found in the remains of an ancient Hunnic elite burial in Hungary. A Neolithic individual from modern-day Armenia was also identified as belonging to haplogroup L1a as well as having red hair and blue eyes.
Nomenclature
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 (Karafet 2008). Subsequent updates have been quarterly and biannual. The current version is a revision of the 2010 update.
The following research teams per their publications were represented in the creation of the YCC Tree.