Haplogroup J2
Main article : Haplogroup J2
J2 originated in northern Mesopotamia, and spread westward to Anatolia and southern Europe, and eastward to Persia and India. J2 is related to the Ancient Etruscans, (Minoan) Greeks, southern Anatolians, Phoenicians, Assyrians and Babylonians.
In Europe, J2 reaches its highest frequency in Greece (especially in Crete, Peloponese and Thrace), southern and central Italy, southern France, and southern Spain. The ancient Greeks and Phoenicians were the main driving forces behind the spread J2 around the western and southern Mediterranean.
J2 is thought to have arrived in Greece from Anatolia somtime between the (late) Neolithic and the Bronze Age.
Middle-Eastern and European J2a
The geographic distribution of J2a bears a strong correlation with the diffusion of agriculture from northern Mesopotamia (where it peaks) towards Anatolia, Greece, the whole Middle East, Iran, Afghanistan, Pakistan and western India. Its 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 played a more decisive role than other peoples. This makes sense considering that the Phoenicians/Carthaginians 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 J2a3d (M319) appears to be native to Crete. J2a also reaches high frequencies in Anatolia and the southern Caucasus.
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 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
The mutation founding the J2b subclade might have originated in Greece (or in Anatolia ?), like haplogroup E-V13 (see below) to which it is closely linked. The propagation of J2b and E-V13 corresponds roughly to the ancient Greek and Roman spheres of influence. Apart from Europe, J2b is also found all around India, but only at moderate frequencies in between Europe and India, meaning that, unlike for J2a, it was not a progresive and continuous diffusion, as is to be expected from the spread of agriculture. 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 (see R1b history), spreading with them the Proto-Indo-European language, bronze technology and domestic animals to the Caspian steppe before the expansion of this new culture to Central and South Asia (see R1a history).
