Haplogruppe L (Y-DNA)

In human genetics, Haplogroup L (M20) is a Y-chromosome DNA haplogroup.

This haplogroup is associated with South Asia. It has also been found at low frequencies among populations of Central Asia, Russia, and Southern Europe along the coast of the Mediterranean Sea as far west as Italy. It is a descendant haplogroup of haplogroup K, and is believed to have first appeared approximately 30,000 years ago.

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). It is especially frequent among Dravidian upper and middle castes (ca. 17-19%), but very rare in Aryan upper and middle castes (ca. 5-6%), which suggests that it may have been (perhaps besides J2) the original Y-haplogroup of the Dravidian creators of the Indus Valley Civilization (Sengupta et al. 2006). Its highest frequency and diversity can be found in western Pakistan/Baluchistan (28%), from where the agricultural creators of this civilization colonized the Indus valley in the 4th millenium BC (Qamar et al. 2002). 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 indicates that it was not a Y-haplogroup of the original paleolithic population of India.

Sengupta et al. (2006) recently discovered three subbranches of haplogroup L: L1 (M76), L2 (M317) and L3 (M357). All three are present in Pakistan, but L1 only in India. Unfortunately, there seems to be little interest in the origin and distribution of this haplogroup outside India.

References

A. Basu et al.: Ethnic India: A Genomic View, With Special Reference to Peopling and Structure. Genome research, 2003, http://www.genome.org/cgi/doi/10.1101/gr.1413403.
R. Cordaux et al.: Independent Origins of Indian Caste and Tribal Paternal Lineages. Current Biology, 2004, Vol. 14, p. 231–235
R. Qamar et al.: Y-Chromosomal DNA Variation in Pakistan. American Journal of Human Genetics, 2002, p. 1107-1124
S. Sahoo et al.: A prehistory of Indian Y chromosomes: Evaluating demic diffusion scenarios. PNAS 2006, www.pnas.org/cgi/doi/10.1073/pnas.0507714103
S. Sengupta et al.: Polarity and Temporality of High-Resolution Y-Chromosome Distributions in India Identify Both Indigenous and Exogenous Expansions and Reveal Minor Genetic Influence of Central Asian Pastoralists. American Journal of Human Genetics, 2006, p. 202-221
I. Thamseem et al.: Genetic affinities among the lower castes and tribal groups of India: Inference from Y chromosome and mitochondrial DNA. BMC Genetics, 2006, http://www.biomedcentral.com/1471-2156/7/42

External links

Spread of Haplogroup L, from National Geographic


Adam des Y-Chromosoms
	A00		A0’1'2’3'4
		A0	A1’2'3’4
			A1	A2’3'4
				A2’3	A4=BCDEF
			A2	A3		B		CT
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						DE				CF
			D		E				C		F
							\|
								G								IJK		H
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						G1	G2								IJ	K
															\|					\|
												I		J					L			K(xLT)	T
												\|				\|						\|
										I1			I2			J1		J2			M	NO	P		S
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										N		O											Q	R
																									\|
																							R1		R2
																							\|
																						R1a		R1b