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 agriculture in the Levant (which seems to have been linked to haplogroup G and perhaps also E1b1b). A second expansion of J2 could have occured with the advent of metallurgy (also from Anatolia and 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.
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 spread of chieftains and kings' lineages through a long tradition of polygamy, a practice that the Russians have tried to supress 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%), Sicily (26.5%), Lebanon (26%), Turkey (24%, with peaks of 30% in the Marmara region and in central Anatolia), South Italy (23.5%), Bulgaria (20%), Albania (19.5%), and continental Greece (19% excluding northern Greece), 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, which, combined to the fact that they speak a language descended from Latin, suggests that they could have a greater part of Roman (Italian) ancestry than other ethnic groups in the Balkans.
History & Subclades
Two main subclades divide haplogroup J2: J2a (M410) and J2b (M12, M102, M221, M314).
Middle-Eastern and European J2a
J2a's strong presence in Italy is owed to the migration of the Etruscans from the Near East to central and northern Italy, and to the Greek colonisation of southern Italy.
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 higher frequency zone of southern Analusia.
The Romans surely 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.
The world's maximum concentrations of J2a is in Crete (32% of the population). The subclade J2a4d (M319) appears to be native to Crete.
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 Central Asia by the R1a Indo-European warriors who descended from modern 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 southern Central Asia with the expansion of Middle Eastern people during the Neolithic and mixed with the local hunter-gatherers belonging chiefly to R2 (and possibly some pre-Indo-European R1a).
J2b has a quite different distribution from J2a. J2b seems to have a stronger association with the Chalcolithic cultures of Southeast Europe, and 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. J2b is also found in the Pontic Steppe, the North Caucasus, Central Asia and in South Asia, particularly in India. Its very low frequency in the Middle East though suggests that, unlike for J2a, it was not spread a progresive and continuous diffusion of the Neolithic lifestyle. For this reason, and because it is generally found among the upper castes of India, it is thought that some J2b lineages might have been part of the Indo-Aryan invasions of South Asia (3,500 years ago) alongside R1a1a. It is conceivable that a minority of J2b, G2a3b1 and R1b1b from the Caucasus region migrated to the Volga-Ural region in the early Bronze Age, spreading 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 (see R1a history).