Haplogroup J2 (Y-DNA)

Origins

Haplogroup J2 is thought to have appeared somewhere in the Middle East towards the end of the last glaciation, between 15,000 and 22,000 years ago. Its present geographic distribution argue in favour of a Neolithic expansion from the Fertile Crescent. This expansion probably correlated with the diffusion of domesticated of cattle and goats (starting c. 8000-9000 BCE) from the Zagros mountains and northern Mesopotamia, rather than with the development of cereal agriculture in the Levant (which appears to be linked rather to haplogroups G2 and E1b1b). A second expansion of J2 could have occured with the advent of metallurgy, notably copper working (from the Lower Danube valley, central Anatolia and northern Mesopotamia), and the rise of some of the oldest civilisations.

Quite a few ancient Mediterranean and Middle Eastern civilisations flourished in territories where J2 lineages were preponderant. This is the case of the Hattians, the Hurrians, the Etruscans, the Minoans, the Greeks, the  Phoenicians (and their Carthaginian offshoot), the Israelites, and to a lower extent also the Romans, the Assyrians and the Persians. All the great seafaring civilisations from the middle Bronze Age to the Iron Age were dominated by J2 men.

There is a distinct association of ancient J2 civilisations with bull worship. The oldest evidence of a cult of the bull can be traced back to Neolithic central Anatolia, notably at the sites of Çatalhöyük and Alaca Höyük. Bull depictions are omnipresent in Minoan frescos and ceramics in Crete. Bull-masked terracotta figurines and bull-horned stone altars have been found in Cyprus (dating back as far as the Neolithic, the first presumed expansion of J2 from West Asia). The Hattians, Sumerians, Babylonians, Canaaites, and Carthaginians all had bull deities (in contrast with Indo-European or East Asian religions). The sacred bull of Hinduism, Nandi, present in all temples dedicated to Shiva or Parvati, does not have an Indo-European origin, but can be traced back to Indus Valley civilisation. Minoan Crete, Hittite Anatolia, the Levant, Bactria and the Indus Valley also shared a tradition of bull leaping, the ritual of dodging the charge of a bull. It survives today in the traditional bullfighting of Andalusia in Spain and Provence in France, two regions with a high percentage of J2 lineages.

Geographic distribution

Distribution of haplogroup J2 in Europe, the Middle East & North Africa

The world's highest frequency of J2 is found among the Ingush (88% of the male lineages) and Chechen (56%) people in the Northeast Caucasus. Both belong to the Nakh ethnic group, who have inhabited that territory since at least 3000 BCE. Their language is distantly related to Dagestanian languages, but not to any other linguistic group. However, Dagestani peoples (Dargins, Lezgins, Avars) belong predominantly to haplogroup J1 (84% among the Dargins) and almost completely lack J2 lineages. Other high incidence of haplogroup J2 are found in many other Caucasian populations, including the Azeri (30%), the Georgians (27%), the Kumyks (25%), and the Armenians (22%). Nevertheless, it is very unlikely that haplogroups J2 originated in the Caucasus because of the low genetic diversity in the region. Most Caucasian people belong to the same J2a4b (M67) subclade. The high local frequencies observed would rather be the result of founder effects, for instance the proliferation of chieftains and kings's lineages through a long tradition of polygamy, a practice that the Russians have tried to suppress since their conquest of the Caucasus in the 19th century.

Outside the Caucasus, the highest frequencies of J2 are observed in Cyprus (37%), Crete (34%), northern Iraq (28%), Lebanon (26%), Turkey (24%, with peaks of 30% in the Marmara region and in central Anatolia), Greece (23%), Central Italy (23%), Sicily (23%), South Italy (21.5%), and Albania (19.5%), as well as among Jewish people (19 to 25%).

One fourth of the Vlach people (isolated communities of Romance language speakers in the Balkans) belong to J2, considerably more than the average of Macedonia and northern Greece where they live. This, combined to the fact that they speak a language descended from Latin, suggests that they could have a greater part of Roman (or at least Italian) ancestry than other ethnic groups in the Balkans.

Subclades

Two main subclades divide haplogroup J2: J2a (M410, L152, L212/PF4988, L559/PF4986) and J2b (M12, M102, M221, M314).

• J2a1-M47 is found at low frequency (1-5%) in Anatolia, Georgia, Iran, Iraq and Gulf states.
• J2a1-M67 is the most common subclade in the Caucasus (Vainakhs, Ingushs, Chechens, Georgians, Ossetians, Balkars) and in the Levant (Lebanese, Jews). It is also common in western India, the Arabian Peninsula, Anatolia (esp. north-west), Greece (esp. Crete), Italy (esp. Marche and Abruzzo) and Iberia. M67 was probably a major Neolithic lineage expanding from the Fertile Crescent to Greece to the west and the Indus valley to the east.
• J2a1-M68 a minor subclade found in Iraq and India.
• J2a1-M319 has been found chiefly in Greece (esp. in Crete) and Italy, and at low frequencies around Western Europe (perhaps diffused by the Romans).
• J2a1-M339 is a very minor Anatolian subclade.
• J2a1-M419 is a minor subclade detected in northern Iran.
• J2a1-P81 is a very minor Anatolian subclade.
• J2a1-L24 is the most widespread subclade of J2a, with a distribution ranging from the Middle East to Europe, North Africa and South Asia.
• J2a1-M158 has been found in Anatolia, Iberia, Pakistan and India.
• J2a1-L84 is a minor subclade detected in the Balkans.
• J2a1-L25 is the main branch of L24 and is subdivided in many subclades.
• J2a1-F3133 is found in Anatolia, Syria, Iran, Central Asia and Saudi Arabia.
• J2a1-F761 is the Western European subclade of F3133, found in Italy, France, the Benelux and England.
• J2a1-L192.2 is found in Anatolia, North Africa, Iran and Kerala (India).
• J2a1-PF4888 is found in the Middle East and among Ashkenazi Jews (F659 subclade: Katz and Cohen).
• J2a1-Z387 and its main subclade L70 (DYS445≤7) are found throughout continental Europe as well as in the Middle East at lower frequency.
• J2a1-PF5169 is a rare subclade that has been found in Saudi Arabia, Switzerland, southern Germany and England.
• J2a2-PF7381 is found at low frequency in southern and Eastern Europe and in the Caucasus.

• J2b1-M205 is found mostly in the southern Balkans and Anatolia.
• J2b2-M241 is found mostly in south-east, central and Eastern Europe and in India.

History

Notwithstanding its strong presence in West Asia today, haplogroup J2 does not seem to have been one of the principal lineages associated with the rise and diffusion of cereal farming from the Fertile Crescent and Anatolia to Europe. The region of origin of J2 is still unclear at present. It is likely that J2 men had settled over most of Anatolia, the South Caucasus and Iran by the end of the Last Glaciation 12,000 years ago. It is possible that J2 hunter-gatherers then goat/sheep herders also lived in the Fertile Crescent during the Neolithic period, although the development of early cereal agriculture is thought to have been conducted by men belonging primarily to haplogroups E1b1b and G2a.

The first expansion of J2 into Europe probably happened during the Late Glacial and immediate postglacial periods(c. 16 to 10 kya), when Anatolian hunter-gatherers moved into the Balkans. This migration would have included J2b and  E-V13 male lineages and assorted J and T maternal lineages (presumably J1c, J2a1, T1a1, T2a1b, T2b, T2e and T2f1). This population would have occupied the modern regions of western Turkey, Greece, Macedonia, Albania, Serbia and Bulgaria. When farmers and herders expanded from the Fertile Crescent during the Early Neolithic, they would have blended with one another before expanding towards Central Europe and Italy. J2b seems to have split in two subclades soon after leaving Anatolia, with J2b1 being found mostly in western Anatolia and Greece, while J2b2 expanded from the Balkans to most of Europe, to Central Asia, India and back to the Middle East (see below).

Middle-Eastern and European J2a

It is very likely that J2a, J1 and G2a were the three dominant male lineages the Early Bronze Age Kura-Araxes culture, which expanded from the South Caucasus to eastern Anatolia, northern Mesopotamia and the western Iran. From then on, J2 men would have definitely have represented a sizeable portion of the population of Bronze and Iron Age civilizations such as the Hurrians, the Assyrians or the Hittites.

The high incidence of J2a in Italy is owed in great part to the migration of the Etruscans from western Anatolia to central and northern Italy, and to the Greek colonisation of southern Italy. Immigration from the eastern Mediterranean to Rome during the Roman Empire, then from Anatolia, Thrace and Greece during the Byzantine period (particularly in north-eastern Italy) further increased the incidence of J2 in the peninsula.

The Phoenicians, Jews, Greeks and Romans all contributed to the presence of J2a in Iberia. The particularly strong frequency of J2a and other Near Eastern haplogroups (J1, E1b1b, T) in the south of the Iberian peninsula, suggest that the Phoenicians and the Carthaginians played a more decisive role than other peoples. This makes sense considering that they were the first to arrive, founded the greatest number of cities (including Gadir/Cadiz, Iberia's oldest city), and their settlements match almost exactly the zone where J2 is found at a higher frequency in southern Andalusia.

The Romans probably helped spread haplogroup J2 within their borders, judging from the distribution of J2 within Europe (frequency over 5%), which bears an uncanny resemblance to the borders of the Roman Empire (once concessions are made for the Germanic invasions that appear to have lowered the frequency of J2 between Belgium and Switzerland).

The highest concentrations of J2a in Europe are found in Crete (32% of the population) and Calabria (26%). J2a-M319, one of the principal J2 subclades in Greece, Italy and Western Europe, reaches is maximum frequency in Crete (6-9%).

Indian J2a

Within India, J2a is more common among the upper castes and decreases in frequency with the caste level. This can be explained by the assimilation of local J2a (and R2) people from Bactria and Pakistan by the R1a Indo-European warriors who descended from the Volga-Ural region of Russia (Sintashta culture) and established themselves for a few centuries in southern Central Asia, immediately north of the Hindu Kush (including the Oxus civilization) before moving on to conquer the Indian subcontinent. J2a would have reached Bactria with the expansion of Neolithic herders from the Middle East who then blended with the indigenous hunter-gatherers belonging chiefly to R2.

J2b: Neolithic Balkans and Indo-Europeans

J2b has a quite different distribution from J2a. J2b seems to have a stronger association with the Neolithic and Chalcolithic cultures of Southeast Europe. It is particularly common in the Balkans, Central Europe and Italy, which is roughly the extent of the European Copper Age culture. Its maximum frequency is achieved around Albania, Kosovo, Montenegro and Northwest Greece - the part of the Balkans which best resisted the Slavic invasions in the Early Middle Ages.

The vast majority of J2b lineages belong to J2b2 and its subclades. While J2b* and J2b1 lineages are mostly restricted to the Caucasus, Anatolia and the Balkans, J2b2 is also found in the Pontic Steppe, in Central Asia and in South Asia, particularly in India. Its very low frequency in the Middle East though suggests that, unlike other J2 lineages it was not disseminated by a demic diffusion of the Neolithic lifestyle.

In many ways the distribution of J2b2 and its subclades is strongly reminiscent of G2a3b1 and its subclades. The most likely hypothesis is that both haplogroups penetrated into the Pontic Steppe region during the Neolithic or Chalcolithic period, either crossing the Caucasus from eastern Anatolia or, more probably, expanding east from the flourishing cultures of 'Old Europe', either as an early expansion of the Thessalian Neolithic or as part of the Carpatho-Balkan Metallurgical Province. J2b2 and G2a3b1 would have integrated the local R1a and R1b tribes in the Pontic steppe and the North Caucasus.

Nowadays J2b2 is found chiefly in south-east and Central Europe, but also in Russia and throughout the Indian subcontinent. All these elements reinforce the hypothesis that J2b2 and G2a3b1 were two minor lineages spread within an R1a-dominant population during the Indo-Aryan invasions of South Asia approximately 3,500 years ago.

Another conceivable possibility is that a minority of J2b2, G2a3b1 and R1b-M269 from the Caucasus region migrated to the Volga-Ural region in the early Bronze Age, propagating with them the Proto-Indo-European language and bronze technology to the Caspian steppe before the expansion of this new culture to Central and South Asia. The drawback of this hypothesis is that it doesn't explain why R1b lineages strongly outnumber J2b2 and G2a3b1 in Europe but not in South Asia.

Distribution of haplogroup J2b (M102) in Europe, the Middle East & North Africa

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