| Haplogroup L | |
| Time of origin | 30,000 years BP |
| Place of origin | South Asia |
| Ancestor | K |
| Defining mutations | M20 |
| Typical members | Indians, Pakistanis & Lebanese Druze |
|---|---|
In human genetics, Haplogroup L (M20) is a Y-chromosome DNA haplogroup.
Contents |
This haplogroup is associated with South Asia. It has also been found at low frequencies among populations of Central Asia, Southwest Asia, Northern Africa, and Southern Europe along the coast of the Mediterranean Sea. It is a descendant haplogroup of haplogroup K, and is believed to have first appeared approximately 30,000 years ago.
Sengupta et al. (2006) recently discovered three subbranches of haplogroup L: L1 (M76), L2 (M317), and L3 (M357). All three are present in Iran and Pakistan, but only L1 is regularly found in India. They make a case for an indigenous origin of L1 in India, by arguing that the spatial distributions of both L1 HG frequency and associated microsatellite variance show a pattern of spread emanating from southern India. By linking haplogroup L1 to the Dravidian speakers, they simultaneously argue for an Indian origin of Dravidian languages. Unfortunately, there seems to be little interest in the origin and distribution of this haplogroup outside India.
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 might belong to the subclade L2 (M317), which is, among South Asian populations, generally the rarest of the subclades of Haplogroup L.
Haplogroup L is currently present in the Indian population at an overall frequency of ca. 7-15% (Basu et al. 2003, Cordaux et al. 2004, Sengupta et al. 2006, Thamseem et al. 2006). Its highest frequency and diversity can be found in south western Pakistan/Balochistan along the coast(28%). The presence of haplogroup L is quite rare among tribal groups (ca. 5,6-7%) (Cordaux et al. 2004, Sengupta et al. 2006, Thamseem et al. 2006), which makessome theorize that it was not a Y-haplogroup of the original Paleolithic population of India.
Earlier studies (e.g. Wells et al. 2001) report a very high frequency (approaching 50%) of Haplogroup L in South India appear to have been due to extrapolation from data obtained from a sample of 84 Kallars, a Tamil-speaking warrior caste of Tamil Nadu, among whom 40 (approx. 48%) displayed the M20 mutation that defines Haplogroup L. Subsequent studies of various Indian populations have shown this high frequency of Haplogroup L among the Kallars to be an anomaly in the region; Haplogroup L Y-chromosomes rarely comprise even 25% of the Y-chromosome diversity among any Indian population.
L3 (M357) is found frequently among Burusho and Pashtuns, with a moderate distribution among the general Pakistani population particularly along the Indus river.
L3a (PK3) is found in a great percentage (approximately 23%) of Kalash in northwest Pakistan.
In a small sample of Lebanese Druze haplogroup L was found in 7 out of 20 (35%), which is present in only about 2% of the general Arab population of the Middle East. [1][2]
Haplogroup L is also relatively common in Iran (4/117 or 3.4% L1-M76 and 3/117 or 2.6% L2-M317 for a total of 7/117 or 6.0% haplogroup L in southern Iran and 1/33 or 3.0% L3-M357 in northern Iran (Regueiro et al. 2006)) and Turkey (22/523 or 4.2% haplogroup L (Cinnioğlu et al. 2004)).
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 Lebanon, Turkey, Georgia, Greece, Hungary, Calabria, and Andalusia. The sizes of the samples analyzed in this study were generally quite small, so it is possible that the actual frequency of Haplogroup L 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 in Southwest Asia and Europe.
The subclades of Haplogroup L with their defining mutation(s), according to the 2006 ISOGG tree:
|
Human Y-chromosome DNA (Y-DNA) haplogroups (by ethnic groups · famous haplotypes) |
|||||||||||||||||||||||||||||||
| most recent common Y-ancestor | |||||||||||||||||||||||||||||||
| | | |||||||||||||||||||||||||||||||
| A | BT | ||||||||||||||||||||||||||||||
| | | |||||||||||||||||||||||||||||||
| B | CT | ||||||||||||||||||||||||||||||
| | | |||||||||||||||||||||||||||||||
| CF | DE | ||||||||||||||||||||||||||||||
| | | | | ||||||||||||||||||||||||||||||
| C | F | D | E | ||||||||||||||||||||||||||||
| | | |||||||||||||||||||||||||||||||
| G | H | IJK | |||||||||||||||||||||||||||||
| | | |||||||||||||||||||||||||||||||
| IJ | K | ||||||||||||||||||||||||||||||
| | | | | ||||||||||||||||||||||||||||||
| I | J | L | M | NO | P | S | T | ||||||||||||||||||||||||
| | | | | ||||||||||||||||||||||||||||||
| N | O | Q | R | ||||||||||||||||||||||||||||