Genetic studies on Turkish people

The question to what extent a gene flow from Central Asia to Anatolia has contributed to the current gene pool of the Turkish people and the role of the 11th-century settlement by Oghuz Turks have been the subject of several studies. A factor that makes it difficult to give reliable estimates is the problem of distinguishing the effects of different migratory episodes. Thus, although the Turks settled in Anatolia (peacefully or by war) with cultural significance, including the introduction of the Turkish language and Islam, the genetic significance from Central Asia might have been slight, according to some studies.[5][14]

Some of the Turkic peoples originated from Central Asia and so are possibly related with the Xiongnu.[15] Most (89%) of the Xiongnu sequences can be classified as belonging to Asian haplogroups and nearly 11% belong to European haplogroups.[15] The findings indicate that the contacts between European and Asian populations were anterior to the Xiongnu culture,[15] and confirm results reported for two samples from an early 3rd century B.C. Scytho-Siberian population.[16]

According to another archaeological and genetic study in 2010, the DNA found in three skeletons in 2000-year-old elite Xiongnu cemetery in Northeast Asia belonged to C3, D4 and included R1a. The evidence of paternal R1a support the Kurgan expansion hypothesis for the Indo-European expansion from the Volga steppe region.[17] As the R1a was found in Xiongnu people[17] and the present-day people of Central Asia[18] Analysis of skeletal remains from sites attributed to the Xiongnu provides an identification of dolichocephalic Mongoloid, which is ethnically distinct from the neighbouring populations in present-day Mongolia.[19]

According to a different genetic research on 75 individuals from various parts of Turkey, Mergen et al. revealed that the "genetic structure of the mtDNAs in the Turkish population bears some similarities to Turkic Central Asian populations".[20]

In 2001, Benedetto et al. revealed that Central Asian genetic contribution to the current Anatolian mtDNA gene pool was estimated as roughly 30% by comparing the populations of Mediterranean Europe and the Turkic-speaking people of Central Asia.[12] In 2004, Cinnioğlu et al. made a research of Y-DNA including the samples from eight regions of Turkey without classifying the ethnicity of the people, which indicated that high-resolution SNP analysis totally provides evidence of a detectable weak signal (<9%) of gene flow from Central Asia.[4] A 2006 study concluded that the Central Asian contribution to Anatolia for Y-DNA is 13%, mtDNA 22%, alu insertion (autosomal) 15%, autosomal 22%, with respect to Kyrgyzstan, Kazakhstan, Uyghur, Turkmenistan, Uzbekistan.[10] It was later observed that the male contribution from Central Asia to Turkish population with reference to the Balkans was 13%. For all non-Turkic speaking populations, the Central Asian contribution was higher than in Turkey.[11] According to the study, "the contributions ranging between 13%–58% must be considered with a caution because they harbor uncertainties about the state of pre-nomadic invasion and further local movements."[11]

Y chromosome Haplogroup distribution of Turkish people.[4]

According to Cinnioğlu et al. (2004),[4] there are many Y-DNA haplogroups present in Turkey. Most haplogroups in Turkey are shared with their West Asian and Caucasian neighbours. The most common haplogroup in Turkey is J2 (24%), which is widespread among the Mediterranean, Caucasian and West Asian populations. Haplogroups that are common in Europe (R1b and I – 20%), South Asia (L, R2, H – 5.7%) and Africa (A, E3*, E3a – 1%) are also present. By contrast, Central Asian haplogroups are rarer (C, Q and O).

However, the figure may rise to 36% if K, R1a, R1b and L (which infrequently occur in Central Asia but are notable in many other Western Turkic groups) are also included. J2 is also frequently found in Central Asia, a notably high frequency (30.4%) being observed particularly among Uzbeks.[21]

Some of the percentages identified were:[4]

• J2=24% - J2 (M172)[4] J-M172 (or J2) may reflect the spread of Anatolian farmers.[22] J2-M172 is "mainly confined to the Mediterranean coastal areas, southeastern Europe and Anatolia", as well as West Asia and Central Asia.[23]
• R1b=15.9%[4] Found in Europe, West Asia, Central Asia, Southern Asia, some parts of the Sahel region of Africa.[24]

• G=10.9%[4] Haplogroup G has also been associated with the spread of agriculture (together with J2 clades), and is "largely restricted to populations of the Caucasus and the Near/Middle East and southern Europe."[25]

• E3b-M35=10.7%[4] (E3b1-M78 and E3b3-M123 accounting for all E representatives in the sample, besides a single E3b2-M81 chromosome). E-M78 occurs commonly along a line from the Horn of Africa, via Egypt to the Balkans.[26] Haplogroup E-M123 is found in both Africa and Eurasia.
• J1=9%[4]
• R1a=6.9%[4]
• I=5.3%[4]
• K=4.5%[4]
• L=4.2%[4]
• N=3.8%[4]
• T=2.5%[4]
• Q=1.9%[4]
• C=1.3%[4]
• R2=0.96% [4]

Others markers than occurs in less than 1% are H, A, E3a, O, R1*.

Further research on Turkish Y-DNA groups

Y-DNA comparison of Turkish and Greek speaking populations of Cyprus, Anatolia, Thrace, the Aegean, and peninsular Greece

A study in Turkey by Gökçümen (2008)[27] took into account oral histories and historical records. They went to four settlements in Central Anatolia and did a random selection from a group of university students, like in many other studies. Accordingly, here are the results:

1) In an Afshar village near Ankara where, according to oral tradition, the ancestors of the inhabitants came from Central Asia, the researchers found that 57% of the villagers had haplogroup L, 13% had haplogroup Q and 3% had haplogroup N. It was considered that examples of haplogroup L, which is most common in South Asia, might be a result of Central Asian migration even though the presence of haplogroup L in Central Asia itself was most likely a result of migration from South Asia. Therefore, Central Asian haplogroups potentially occurred in 73% of males in the village. Furthermore, 10% of the Afshars had haplogroups E3a and E3b, while only 13% had haplogroup J2a, the most common in Turkey.

2) The inhabitants of an older Turkish village that had little migration had about 25% of haplogroup N and 25% of J2a, with 3% of G and close to 30% of R1 variants (mostly R1b).

Whole genome sequencing of Turkish individuals[2]

A study of Turkish genetics in 2014 used whole genome sequencing of individuals.[2] Led by Can Alkan at the University of Washington in Seattle, the study was published in the journal BMC Genomics. Its authors showed that the genetic variation of contemporary Turks clusters with South European populations, as expected, but it also shows signatures of relatively-recent contribution from ancestral East Asian populations. It estimated the weights for the migration events predicted to originate from the East Asian branch into Turkey at 21.7% (see Figure 2 by Alkan et al.).[2]

"(B) A population tree based on “Treemix” analysis. The populations included are as follows: Turkey (TUR); Tuscans in Italy (TSI); Iberian populations in Spain (IBS); British from England and Scotland (GBR); Finnish from Finland (FIN); Utah residents with Northern and Western European ancestry (CEU); Han Chinese in Beijing, China (CHB); Japanese in Tokyo, Japan (JPT); Han Chinese South (CHS); Yoruba in Ibadan, Nigeria (YRI); Luhya in Webuye, Kenya (LWK). Populations with high degree of admixture (Native American and African American populations) were not included to simplify the analysis. The Yoruban population was used to root the tree. In total four migration events were estimated. The weights for the migration events predicted to originate from the East Asian branch into current-day Turkey was 0.217 (21.7%), from the ancestral Eurasian branch into the Turkey-Tuscan clade was 0.048, from the African branch into Iberia was 0.026, from the Japanese branch into Finland was 0.079."[2]

A 2001 study, which looked at HLA alleles suggested that "Turks, Kurds, Armenians, Iranians, Jews, Lebanese and other (Eastern and Western) Mediterranean groups seem to share a common ancestry" and historical populations such as Anatolian Hittite and Hurrian groups (older than 2000 B.C.) "may have given rise to present‐day Kurdish, Armenian and Turkish populations."[3] A 2004 study, which looked at 11 human‐specific Alu insertion polymorphisms among Aromun, Macedonians, Albanians, Romanians, Greeks, and Turks, suggested a common ancestry for these populations.[28]

In 2011, Aram Yardumian and Theodore G. Schurr published their study "Who Are the Anatolian Turks? A Reappraisal of the Anthropological Genetic Evidence." They revealed the impossibility of long-term and continuing genetic contacts between Anatolia and Siberia and confirmed the presence of significant mitochondrial DNA and Y-chromosome divergence between these regions, with minimal admixture. The research confirms also the lack of mass migration and suggested that it was irregular punctuated migration events that engendered large-scale shifts in language and culture among Anatolia's diverse autochthonous inhabitants.[7]

Estimated cluster membership bar plot for populations in West Asia, Europe, Africa, South Central Asia, Central Asia, and Siberia. The populations with the largest orange bars, including Turkish people, are located primarily in Southern and Mediterranean Europe, and northern part of Southwest Asia.[8]

A study in 2015, however, found, "Previous genetic studies have generally used Turks as representatives of ancient Anatolians. Our results show that Turks are genetically shifted towards Central Asians, a pattern consistent with a history of mixture with populations from this region." The authors found "7.9% (±0.4) East Asian ancestry in Turks from admixture occurring 800 (±170) years ago."[13]

According to a 2012 study of ethnic Turks, "Turkish population has a close genetic similarity to Middle Eastern and European populations and some degree of similarity to South Asian and Central Asian populations."[29] At K = 3 level, using individuals from the Middle East (Druze and Palestinian), Europe (French, Italian, Tuscan and Sardinian) to obtain a more representative database for Central Asia (Uygur, Hazara and Kyrgyz), clustering results indicated that the contributions were 45%, 40% and 15% for the Middle Eastern, European and Central Asian populations, respectively. For K = 4 level, results for paternal ancestry were 38% European, 35% Middle Eastern, 18% South Asian and 9% Central Asian. K= 7 results of paternal ancestry were 77% European, 12% South Asian, 4% Middle Eastern, 6% Central Asian. However, Hodoglugil et al. caution that results may indicate previous population movements (such as migration, admixture) or genetic drift.[29] The study indicated that the Turkish genetic structure is unique, and admixture of Turkish people reflects the population migration patterns.[29] Among all sampled groups, the Adygei population (Circassians) from the Caucasus was closest to the Turkish samples among sampled European (French, Italian), Middle Eastern (Druze, Palestinian), and Central (Kyrgyz, Hazara, Uygur), South (Pakistani), and East Asian (Mongolian, Han) populations.[29]

Population relationships based on Fst distance estimations. Turks have the lowest Fst distances with OCA (Caucasus) and OME (Iranians and Syrians) groups, compared to other groups or populations such as East-Central European populations (OEC), European (including Northern and Eastern European), Sardinian, Roma, and Turkmens[9]

A study involving mitochondrial analysis of a Byzantine-era population, whose samples were gathered from excavations in the archaeological site of Sagalassos, found that Sagalassos samples were closest to modern samples from "Turkey, Crimea, Iran and Italy (Campania and Puglia), Cyprus and the Balkans (Bulgaria, Croatia and Greece)."[30] Modern-day samples from the nearby town of Ağlasun showed that lineages of East Eurasian descent assigned to macro-haplogroup M were found in the modern samples from Ağlasun. This haplogroup is significantly more frequent in Ağlasun (15%) than in Byzantine Sagalassos, but the study "no genetic discontinuity across two millennia in the region."[31]

A 2019 study found that Turkish people cluster with Southern and Mediterranean Europe populations along with groups in the northern part of Southwest Asia (such as the populations from Caucasus, Northern Iraq, and Iranians).[8] Another 2019 study found that Turkish people have the lowest Fst distances with Caucasus population group and Iranian-Syrian group, compared to East-Central European, European (including Northern and Eastern European), Sardinian, Roma, and Turkmen groups or populations. Caucasus group in the study included samples from "Abkhazians, Adygey, Armenians, Balkars, Chechens, Georgians, Kumyks, Kurds, Lezgins, Nogays, and North Ossetia."[9]

With the development of genetic researches of human history in the 21st century, criticism has arisen in Turkey by researchers traditionally concerned with the subject, such as anthropologists, archaeologists and historians. That kind of criticism is concerned with the formation of the biological construct of historical communities, which denies the 20th-century scholarly discourse by transforming the entities into purely-biological spheres. While the Central Asiatic origin of the Turkish people is a relatively new research topic in the history, which was developed in the late Ottoman Empire and the Republic of Turkey, its clash with modern human genetics researches raises in a new light the questions: What was a "Turk(ic)" and who are the modern Turks?[32]

• Demographics of Turkey
• History of the Turkish people
• Archaeogenetics of the Near East
• Genetic history of Europe
• Turkification