Genetic studies on Sinhalese

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The migration routes of the ancestors of the Sinhalese and other ethnic groups into Sri Lanka.

Genetic studies on the Sinhalese is part of population genetics investigating the origins of the Sinhalese populations today.

Studies looking at the origin of the Sinhalese have been contradictory. Older studies suggest a predominantly Tamil origin followed by a significant Bengali contribution with no North Western Indian contribution.[1][2] While modern studies point towards a predominantly Bengali contribution and a minor Tamil and North Western Indian contribution.[3][4][5]

All studies agree however, that there is a significant relationship between the Sinhalese and the Tamil, Keralite and Bengali. This is also supported by a genetic distance study, which showed low differences in genetic distance between the Sinhalese and the Tamil, Keralite and Bengali volunteers.[3]

Predominantly Bengali origin[edit]

Genetic admixture of Sinhalese by Dr. Saha Papiha

An Alu polymorphism analysis of Sinhalese from Colombo by Dr Sarabjit Mastanain in 2007 using Tamil, Bengali, Gujarati (Patel), and Punjabi as parental populations found different proportions of genetic contribution:[5]

Statistical Method Bengali Tamil North Western
Point Estimate 57.49% 42.5% -
Maximum Likelihood Method 88.07% - -
Using Tamil, Bengali and North West as parenteral population 50-66% 11-30% 20-23%

A genetic distance analysis by Dr Robet Kirk also concluded that the modern Sinhalese are most closely related to the Bengalis.[3]

This is further substantiated by a VNTR study, which found 82% of Sinhalese genes to originate from Bengali admixture:[4]

Parenteral population Bengali Tamil Gujarati Punjabi
Using Tamil and Bengali as parenteral population 70.03% 29.97% -
Using Tamil, Bengali and Gujarati as parenteral population 71.82% 16.38% 11.82%
Using Bengal, Gujarati and Punjabi as parenteral population 82.09% - 15.39% 2.52%

D1S80 allele frequency (A popular allele for genetic fingerprinting) is also similar between the Sinhalese and Bengalis, suggesting the two groups are closely related.[6] The Sinhalese also have similar frequencies of the allele MTHFR 677T (13%) to West Bengalis (17%).[7][8]

These findings are compatible with the historical chronicles the Mahavamsa and Dipavamsa. Which describe a Vanga prince (Prince Vijaya)from Sinhapura in Lata or Lala of being an early settler of Sri Lanka and the progenitor of the Sinhalese. The Vangas are generally identified as Bengalis. On the other hand, Lata is identified with modern day Gujarat, and Sinhapura with modern Sihor in the Kathiawar peninsular of Gujarat. Furthermore, the Mahawamsa states that Vijaya landed first at Supparaka (identified with modern Sopara, in the Thane distrcit of Maharashtra), while the Dipavamsa mentions 'Suppara' and a further intermediate port, Bharukkaccha (modern Bharuch, a port in Gujarat, at the mouth of the Narmada). Vijaya's grandfather was reputed to be a Lion, and Lions have not lived in Bengal in historic times, while they have in Gujarat so it was possible that the Lion image was either borrowed or.

Genetic distance of Sinhalese to other ethnic groups in the Indian Subcontinent according to an Alu Polymorphism analysis.
Genetic distance of Sinhalese to other ethnic groups.

A study in 2007 found similar frequencies of the allele HLA-A*02 in sinhalese (7.4%) and North Indian subjects (6.7%). HLA-A*02 is a rare allele which has a relatively high frequency in North Indian populations and is considered to be a novel allele among the North Indian population. This suggests possible North Indian origin of the Sinhalese.[9]

Linguistically the Sinhalese are closer to North Indians than South Indians, as the Sinhala language is a member of the Indo-Aryan languages.[10]

Tamil Genetic Admixture[edit]

Genetic admixture of Sinhalese by Dr. Gautam K. Kshatriya.

According to a genetic admixture study by Dr. Gautam K. Kshatriya performed in 1995, the Sinhalese have their origins in North-East India, particularly West Bengal .

Due to relatively easy access from South India and Tamil workers being brought from South India under British rule, mixing of the Tamil and Sinhalese groups has been occurring for many generations. The Sinhalese and Sri Lankan Tamils have been in close proximity to each other historically, linguistically, and culturally for over 2000 years. For example, the Sinhalese and South Indian Tamils have similar cultures in terms of kinship classification and housing.[11] This explains Kshatriya's findings of a common gene pool of 55%.[1]

When studying Genetic Flow from Southern Asia, Kshatriya found that some Sinhalese had the greatest contribution from South Indian Tamils (69.86% +/- 0.61), followed by Bengalis from the North East of India (25.41% +/- 0.51). Similarly, Sri Lankan Tamils have a greater contribution from the Sinhalese of Sri Lanka (55.20% +/- 9.47) than Indian Tamils (16.63% +/- 8.73).

The study also suggested that 75% of Sinhalese genes have Tamil admixture and the Sinhalese have the least genetic affinity with Western and North Western Indians .[4]

Relationship to other ethnic groups in Sri Lanka[edit]

A study looking at genetic variation of the FUT2 gene in the Sinhalese and Sri Lankan Tamil population, found similar genetic backgrounds for both ethnic groups, with little genetic flow from other neighbouring Asian population groups.[12] Studies have also found no significant difference with regards to blood group, blood genetic markers and single-nucleotide polymorphism between the Sinhalese and other ethnic groups in Sri Lanka.[2][13][14] Another study has also found "no significant genetic variation among the major ethnic groups in Sri Lanka".[15] This is further supported by a study which found very similar frequencies of alleles MTHFR 677T, F2 20210A & F5 1691A in South Indian Tamil, Sinhalese, Sri Lankan Tamil and Moor populations.[8]

Relationship to East Asians and Roma[edit]

The Sinhalese are likely to have received little or no genetic flow from neighboring East or Southeast Asian populations,[16] and have closer affinities to Western Eurasia. This is supported by study looking at protein and blood group loci that suggests the Sinhalese are closer to Iranians and Afghans than to Mongoloids[17] and comparisons of root and canal morphology of Sri Lankan mandibular molars.[18]

A 2003 Nature study found the Romani language to be most closely related to Sinhalese language.[19] In addition the Romani people and Sinhalese both have a high requency of Haplogroup H (Y-DNA).[20] The Sinhalese and Sinti Roma also have a high frequency of Haplogroup R2 (38% and 53% respectively), as do West Bengalis of which the Sinhalese are related to.[21][22] These haplogroups are thought to have arisen 25,000-30,000 YBP.[22][23] Therefore the Sinhalese and Roma may both be related to the same group of paleolithic inhabitants that lived in Central India 25,000 years ago.

Skin pigmentation[edit]

In 2008 a study looked at SLC24A5 polymorphism which accounts for 25-40% of the skin complexion difference between Europeans and Africans[24] and up to 30% of skin colour variation in South Asians.[25][26] The study found that the rs1426654 SNP of SLC24A5, which is fixed in European populations[27] and found more commonly in light skinned individuals than dark skinned individuals (49% compared to 10%), has a frequency of ~50% in the Sinhalese and ~30% in Sri Lankan tamils.[26] This allele could have arisen in the Sinhalese due to North East Asian genetic admixture, migration or strong selection factors.

References[edit]

  1. ^ a b Kshatriya GK (December 1995). "Genetic affinities of Sri Lankan populations". Human Biology 67 (6): 843–66. PMID 8543296. 
  2. ^ a b Saha, N. (1988). "Blood genetic markers in Sri Lankan populations—reappraisal of the legend of Prince Vijaya". American Journal of Physical Anthropology 76 (2): 217–25. doi:10.1002/ajpa.1330760210. PMID 3166342. 
  3. ^ a b c Kirk, R. L. (1976). "The legend of Prince Vijaya — a study of Sinhalese origins". American Journal of Physical Anthropology 45 (1): 91–99. doi:10.1002/ajpa.1330450112. 
  4. ^ a b c Papiha SS, Mastana SS, Purandare CA, Jayasekara R, Chakraborty R (October 1996). "Population genetic study of three VNTR loci (D2S44, D7S22, and D12S11) in five ethnically defined populations of the Indian subcontinent". Human Biology 68 (5): 819–35. PMID 8908803. 
  5. ^ a b http://www.krepublishers.com/06-Special%20Volume-Journal/T-Anth-00-Special%20Volumes/T-Anth-SI-03-Anth-Today-Web/Anth-SI-03-29-Mastana-S/Anth-SI-03-29-Mastana-S-Tt.pdf
  6. ^ Surinder Singh Papiha (1999). Genomic Diversity: Applications in Human Population Genetics. London: Springer. 7.
  7. ^ Mukhopadhyay, 2007 K. Mukhopadhyay et al., MTHFR gene polymorphisms analyzed in population from Kolkata, West Bengal, Indian J. Human Genet. 13 (2007), p. 38.
  8. ^ a b Vajira H.W. Dissanayake, Lakshini Y. Weerasekera, C. Gayani Gammulla, Rohan W. Jayasekara, Prevalence of genetic thrombophilic polymorphisms in the Sri Lankan population -- implications for association study design and clinical genetic testing services, Experimental and Molecular Pathology, Volume 87, Issue 2, October 2009, Pages 159-162
  9. ^ Malavige, G. N.; Rostron, T.; Seneviratne, S. L.; Fernando, S.; Sivayogan, S.; Wijewickrama, A.; Ogg, G. S. (2007). "HLA analysis of Sri Lankan Sinhalese predicts North Indian origin". International Journal of Immunogenetics 34 (5): 313–5. doi:10.1111/j.1744-313X.2007.00698.x. PMID 17845299. 
  10. ^ Indo-Aryan languages
  11. ^ The Structure of the Sinhalese Kindred: A Re-Examination of the Dravidian Terminology, Nur Yalman, American Anthropologist, New Series, Vol. 64, No. 3, Part 1 (Jun., 1962), pp. 548-575 Published by: Blackwell Publishing on behalf of the American Anthropological Association Stable URL: http://www.jstor.org/stable/667927
  12. ^ Soejima M, Koda Y (December 2005). "Denaturing high-performance liquid chromatography-based genotyping and genetic variation of FUT2 in Sri Lanka". Transfusion 45 (12): 1934–9. doi:10.1111/j.1537-2995.2005.00651.x. PMID 16371047. 
  13. ^ D. F. Roberts, C. K. Creen, K. P. Abeyaratne, Man, New Series, Vol. 7, No. 1 (Mar., 1972), pp. 122-127, Published by: Royal Anthropological Institute of Great Britain and Ireland, Stable URL: http://www.jstor.org/stable/2799860
  14. ^ Dissanayake VH, Giles V, Jayasekara RW et al. (April 2009). "A study of three candidate genes for pre-eclampsia in a Sinhalese population from Sri Lanka". The Journal of Obstetrics and Gynaecology Research 35 (2): 234–42. doi:10.1111/j.1447-0756.2008.00926.x. PMID 19708171. 
  15. ^ Ruwan J. Illeperuma, Samudi N. Mohotti, Thilini M. De Silva, Neil D. Fernandopulle, W.D. Ratnasooriya, Genetic profile of 11 autosomal STR loci among the four major ethnic groups in Sri Lanka, Forensic Science International: Genetics, Volume 3, Issue 3, June 2009, Pages e105-e106
  16. ^ Soejima, Mikiko; Koda, Yoshiro (2006). "Population differences of two coding SNPs in pigmentation-related genes SLC24A5 and SLC45A2". International Journal of Legal Medicine 121 (1): 36–9. doi:10.1007/s00414-006-0112-z. PMID 16847698. 
  17. ^ Roychoudhury AK, Nei M (1985) Genetic relationships between Indians and their neighboring populations. Hum Hered 35:201–206
  18. ^ Peiris, Roshan; Takahashi, Masami; Sasaki, Kayoko; Kanazawa, Eisaku (2007). "Root and canal morphology of permanent mandibular molars in a Sri Lankan population". Odontology 95 (1): 16–23. doi:10.1007/s10266-007-0074-8. PMID 17660977. 
  19. ^ Gray, Russell D.; Atkinson, Quentin D. (2003). "Language-tree divergence times support the Anatolian theory of Indo-European origin". Nature 426 (6965): 435–9. Bibcode:2003Natur.426..435G. doi:10.1038/nature02029. PMID 14647380. 
  20. ^ Kivisild T, Rootsi S, Metspalu M et al. (February 2003). "The genetic heritage of the earliest settlers persists both in Indian tribal and caste populations". American Journal of Human Genetics 72 (2): 313–32. doi:10.1086/346068. PMC 379225. PMID 12536373. 
  21. ^ Sengupta, S; Zhivotovsky, L; King, R; Mehdi, S; Edmonds, C; Chow, C; Lin, A; Mitra, M et al. (2006). "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". The American Journal of Human Genetics 78 (2): 202–21. doi:10.1086/499411. PMC 1380230. PMID 16400607. 
  22. ^ a b Jean-Grégoire Manoukian.. (2006). A Synthesis of Haplogroup R2. Available: http://www.ethnoancestry.com/index_files/index_data/Haplogroup_R2_Manoukian.pdf. Last accessed 03 March 2010.
  23. ^ Achilli A, Rengo C, Magri C et al. (November 2004). "The molecular dissection of mtDNA haplogroup H confirms that the Franco-Cantabrian glacial refuge was a major source for the European gene pool". American Journal of Human Genetics 75 (5): 910–8. doi:10.1086/425590. PMC 1182122. PMID 15382008. 
  24. ^ Razib. (2005). Race is skin deep. Available: http://www.gnxp.com/blog/2005/12/race-is-skin-deep.php. Last accessed 3 March 2010.
  25. ^ Razib. (2007). Why brown people are different. Available: . http://scienceblogs.com/gnxp/2007/09/why_brown_people_are_different.php. Last accessed 3 March 2010.
  26. ^ a b Soejima M, Koda Y (January 2007). "Population differences of two coding SNPs in pigmentation-related genes SLC24A5 and SLC45A2". International Journal of Legal Medicine 121 (1): 36–9. doi:10.1007/s00414-006-0112-z. PMID 16847698. 
  27. ^ Stanford University. (2009). rs1426654 Chromosome chr15:46213776. Available: http://hgdp.uchicago.edu/cgi-bin/alfreqs.cgi?pos=46213776&chr=chr15&rs=rs1426654&imp=true. Last accessed 3 March 2010.

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