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.
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).
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).
Distribution of haplogroup J2 in Europe, the Middle East & North Africa
Main article : Haplogroup J1
J1 is a Middle Eastern haplogroup, which probably originated in eastern Anatolia, near Lake Van in central Kurdistan. Eastern Anatolia being the region where goats, sheep and cattle were first domesticated in the Middle East, haplogroup J1 is almost certainly linked to the expansion of pastoralist lifestyle throughout the Middle East and Europe. J1 can be divided in two main groups: the J1c3 (P58) subclade, and the other forms of J1 (J1*, J1a, J1b, J1c1 and J1c2).
J1c3 (J-P58) is by far the most widespread subclade of J1. It is a typically Semitic haplogroup, making up most of the population of the Arabian peninsula, where it accounts for approximately 40% t 75% of male lineages. J-P58 is also the Cohen Modal Haplotype. Roughly half of all Cohanim belong to the J-P58 subclade. In the Hebrew Bible the common ancestor of all Cohens is identified as Aaron, the brother of Moses.
J1c3 is thought to have expanded from eastern Anatolia to the Levant, Taurus and Zagros mountains and the Arabian peninsula at the end of the last Ice Age (12,000 years ago) with the seasonal migrations of pastoralists. Arabic speakers recolonised the Arabian peninsula in the Bronze Age from the north-west of the peninsula, close to modern Jordan. The rise of Islam in the 7th century CE played a major part in the re-expansion of J1c3 from Arabia throughout the Middle East, as well as to North Africa, and to a lower extent to Sicily and southern Spain.
Other subclades of J1 are less well studied due to their much lower frequencies. Most of the J1 in the Caucasus, Anatolia and Europe is of the non-J1c3 variety. Other types of J1 most probably spread to Europe during the Neolithic. J1 is particularly common in mountainous regions of Europe (with the notable exception of the Alps and the Carpathians), like Greece, Albania, Italy, central France, and the most rugged parts of Iberia (Asturias, Cantabria, Castile-La Mancha) as well as those with the highest density of Neolithic settlements (Portugal and Andalusia).
Like haplogroup G, J1 might have been of the principal lineages to bring domesticated animals to Europe. Both G and J1 reach their maximal frequencies in the Caucasus, some ethnic groups being almost exclusively J1 (Kubachi, Kaitak, Dargins), while others have extremely high levels of G (Shapsugs, North Ossetians). Most of the ethnic groups in the North Caucasus have between 20 and 40% of each haplogroup, which are by far their two dominant haplogroups. In the South Caucasus (Georgia, Armenia, Azerbaijan), haplogroup J2 comes into the admixture and is in fact slightly higher than either J1 or G.
Distribution of haplogroup J1 in Europe, the Middle East & North Africa
Haplogroup E1b1b (Y-DNA)
Main article : Haplogroup E1b1b Haplogroup E1b1b (formerly E3b) represents the last direct major migration from Africa into Europe. It is believed to have first appeared in the Horn of Africa or southern Africa approximately 26,000 years ago and dispersed to the Middle East during the Upper Paleolithic and Mesolithic periods.
On the European continent it has the highest concentration in north-west Greece, Albania and Kosovo, then fading around the Balkans, the rest of Greece and Western Turkey. Outside Europe, it is also found in most of the Middle East, northern and eastern Africa, especially in Morocco, Lybia, Egypt Yemen, Somalia, Ethiopia and South Africa.