Genetic studies on the Sinhalese is part of population genetics investigating the origins of the Sinhalese population.
All studies agree that there is a significant relationship between the Sinhalese ,the odia people and the Bengalis and South Indian Tamils and that there is a significant genetic relationship between Sri Lankan Tamils and Sinhalese, them being closer to each other than other South Asian populations.This is also supported by a genetic distance study, which showed low differences in genetic distance between the Sinhalese and the Bengali, odia, Tamil, and Keralite volunteers.
According to a study published in 2021 using 16 X-chromosomal short tandem repeat markers (STRs), there is a sex biased demographic history among Sri Lankan ethnicities, where Sinhalese and Moors are closely related with each other. There was no genetic subdivision detected between Sinhalese, Moors and Sri Lankan Tamils while Indian (Upcountry) Tamils were having a subtle but statistically significant difference. The observed close relationship between Moors and Sinhalese maybe explained by the matrimonial bonds made by Moor males with Sinhalese females during their original settlement in Sri Lanka. Further, the phylogram generated for the four main ethnic groups of Sri Lanka was suggestive of an Indian origin for Moors compared to the Arabic origin speculated by some.
A 2017 study conducted by Fumihiko Takeuchi, Tomohiro Katsuya, Ryosuke Kimura and Norihiro Kato showed that the main ancestral population that contributed to the Sinhalese was the "South Asian" component with a significant contribution from the "South Asian and Central Asian" component and smaller contributions from the "Central Asian", "Southeast Asian", "Southeast Asian and East Asian", "East Asian" and "Japanese" components.
The Sinhalese people and other South Asian ethnic groups are of primarily indigenous South Asian (AASI) ancestry. Indigenous South Asians (AASI) form their own genetic lineage, not closely related to populations outside of South Asia.
The AASI originated within South Asia and were genetically isolated from other populations more than 45,000 years BCe. Indigenous South Asian (AASI) ancestry forms the primary ancestry for modern South Asians (between 50% to 70%), next to recent West-Eurasian and East-Eurasian components. The AASI are however not distantly related to the Andamanese peoples, as proposed before. In contrary, the Andamanese (Onge) are closer to various Oceanic groups and received some geneflow from South Asia and East Asia respectively. AASI-like geneflow towards Aboriginal Australians was also detected (up to 30%) and further supports migration waves from South Asia to Oceania.The Paniya people are, next to the Irula and the Soliga, the best proxy for indigenous South Asian ancestry.
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:
|Statistical Method||Bengali||Tamil||North Western|
|Maximum Likelihood Method||88.07%||-||-|
|Using Tamil, Bengali and North West as parental 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.
This is further substantiated by a VNTR study, which found 70-82% of Sinhalese genes to originate from Bengali admixture:
|Using Tamil and Bengali as parental population||70.03%||29.97%||-|
|Using Tamil, Bengali and Gujarati as parental population||71.82%||16.38%||11.82%|
|Using Bengali, Gujarati and Punjabi as parental 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. The Sinhalese also have similar frequencies of the allele MTHFR 677T (13%) to West Bengalis (17%).
A test for Y-chromosome DNA haplogroups conducted by Dr Toomas Kivisild on Sinhalese of Sri Lanka has shown that 23% of the subjects were R1a1a (R-SRY1532) positive. Also in the same test 24.1% of the subjects were R2 positive as subclades of Haplogroup P (92R7). Haplogroup R2 is also found in a considerable percentage among Bengali of India. Sample size used was 87 subjects.
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.
Another study by GK Kshatriya conducted in 1995 assessing the 'Genetic affinities of Sri Lankan Populations' found a large genetic contribution from the Tamils of South India, as well as from the Bengali and Vedda populations. The study was carried out using Sinhalese from regions where Sinhala Tamil interactions were higher and older methods compared to other modern and accurate studies.
|Using Tamil, Bengali and Vedda as parental population||69.86%||25.41%||4.73%|
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. 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. Another study has also found "no significant genetic variation among the major ethnic groups in Sri Lanka". 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.
A genetic study carried out in 2015 by Lian dang et. on origin of Malay people and other populations of Sri Lanka involving 200 Sinhalese people, 103 Tamil people of Sri Lankan origin, 200 Tamil people of Indian origin and 35 Burgher people calculated the averaged genetic makeup across individuals of each population, which show substantially higher amount of Central Asian ancestry and low South Asian ancestry among Sinhalese compared to both Tamil groups.
Genetic studies show that the Sinhalese have received some genetic flow from neighboring populations in East Asia and Southeast Asia, such as from the ethnically diverse and disparate Tibeto-Burman peoples and Austro-Asiatic peoples, which is due to their close genetic links to Northeast India. A 1985 study conducted by Roychoudhury AK and Nei M, indicated the values of genetic distance showed that the Sinhalese people were slightly closer to Mongoloid populations due to gene exchange in the past. In regards to comparisons of root and canal morphology of Sri Lankan mandibular molars, it showed that they were further away from Mongoloid populations. Among haplogroups found in East Asian populations, a lower frequency of East Asian mtDNA haplogroup, G has been found among the populations of Sri Lanka alongside haplogroup D in conjunction with the main mtDNA haplogroup of Sri Lanka's ethnic groups, haplogroup M. In regards to Y-DNA, Haplogroup C-M130 is found at low to moderate frequencies in Sri Lanka.
Genetic markers of immunoglobulin among the Sinhalese show high frequencies of afb1b3 which has its origins in the Yunnan and Guangxi provinces of southern China. It is also found at high frequencies among Odias, certain Nepali and Northeast Indian, southern Han Chinese, Southeast Asian and certain Austronesian populations of the Pacific Islands. At a lower frequency, ab3st is also found among the Sinhalese and is generally found at higher frequencies among northern Han Chinese, Tibetan, Mongolian, Korean and Japanese populations. The Transferrin TF*Dchi allele which is common among East Asian and Native American populations is also found among the Sinhalese. HumDN1*4 and HumDN1*5 are the predominant DNase I genes among the Sinhalese and are also the predominant genes among southern Chinese ethnic groups and the Tamang people of Nepal. A 1988 study conducted by N. Saha, showed the high GC*1F and low GC*1S frequencies among the Sinhalese are comparable to those of the Chinese, Japanese, Koreans, Thais, Malays, Vietnamese, Laotians and Tibetans. A 1998 study conducted by D.E. Hawkey showed dental morphology of the Sinhalese is closely related to those of the Austro-Asiatic populations of East and Northeast India. Hemoglobin E a variant of normal hemoglobin, which originated in and is prevalent among populations in Southeast Asia, is also common among the Sinhalese and can reach up to 40% in Sri Lanka.
In a study that compared the four main Sri Lanka ethnicities (Sinhalese, SL Tamil, Indian Tamil, Moors) with 14 other world populations (Bhil India, Bangladesh, Malaysia, Thailand, China, Japan, Taiwan, Germany, Italy, Sweden, Denmark, North Portugal, Somalia, and Ivory Coast) with eight X chromosome based STR markers using a multidimensional scaling plot (MDS plot), Sri Lankans were clustered together not only with Southeast Asians like Indians and Bangladeshi, but also with Europeans. Indian Tamils were placed towards the periphery of this main cluster, while Southeast Asians, East Asians and Africans were placed at a distant, outside the main cluster. This presentation is thought to align well with the historical claims of population movements in Eurasia where Sinhalese are believed to be descended from Indo-Aryans, who set forth from boarders of the Caspian and Black sea towards Europe and South Asia, early in the third millennium BC.
In 2008 a study looked at SLC24A5 polymorphism which accounts for 25-40% of the skin complexion difference between Europeans and Africans and up to 30% of skin colour variation in South Asians. The study found that the rs1426654 SNP of SLC24A5, which is fixed in European populations and found more commonly in light skinned individuals than dark skinned individuals (49% compared to 10%), has a frequency of around 55% in the Sinhalese and around 25% in Sri Lankan Tamils. This allele could have arisen in the Sinhalese due to further migration from North India or strong selection factors.