Here is the distribution map of the rarest of the nine subclades of haplogroup U in Europe and the Middle East. The origins of U are still very uncertain. Almost all European U2 fits into the U2e subclade, with only a small minority of U2d. All the other subclades are usually found in South Asia. Yet the oldest ancient mtDNA tested to date in Europe, a 30,000-year-old Cro-Magnon from the Kostenki 14 site on the Don River in southern Russia, belonged to haplogroup U2. Nowadays U2 is found in most of Europe, the Middle East and North Africa, but rarely exceeds 2%. The only area where it does exceed 2% are in western France, Denmark, Latvia, Macedonia, parts of Poland, Belarus, and among many ethnic minorities in Russia, like the Udmurts in the Ural region and most Caucasian people. On the other hand, U2 is found at much higher frequencies in India and Pakistan (up to 20% of the population). So is U2 originally European or not ?
U2 was has never been found in any Neolithic sites in Europe. Its first appearance is with the Corded Ware (Chalcolithic to Bronze Age) and Unetice (Bronze Age) cultures in central Europe, two cultures linked with the Indo-Europeans that yielded Y-DNA haplogroups R1a, and in Unetice's case also R1b. Considering its higher frequency in northern Slavic countries today, I'd say that U2 was propagated by R1a Indo-Europeans. The Tajiks, Kirghiz, Turkmen, Uzbeks and other Central Asian ethnicities with high R1a levels and Indo-European connections all have 1-2% of U2. U2 has been found at over 2% in the Altai and at trace frequencies in Mongolia, two regions also settled by R1a (and to a lesser extent R1b). That would seem enough to prove an Indo-European connection.
We could even assume that the U2 in South Asia was brought by Indo-European invaders. The only problem is that U2 subclades in South Asia aren't the same as in Europe. Could it be that the Indo-Europeans were U2* and that U2a, U2b, U2c and U2i developed in South Asia after the IE conquest ? This isn't likely considering that U2 is about 50,000 years old. I rather believe that U2 split in Central Asia during the Palaeolithic, perhaps around the time that Y-haplogroup R split into R1a, R1b and R2, and that the South Asian subclades could be linked to the diffusion of R2, while European ones are connected to both R1a and R1b. That would also explain why U2 is also found in regions which have no or very little R1a, but some R1b, like Jordan, Southwest Europe and even North Africa.
U2 was has never been found in any Neolithic sites in Europe. Its first appearance is with the Corded Ware (Chalcolithic to Bronze Age) and Unetice (Bronze Age) cultures in central Europe, two cultures linked with the Indo-Europeans that yielded Y-DNA haplogroups R1a, and in Unetice's case also R1b. Considering its higher frequency in northern Slavic countries today, I'd say that U2 was propagated by R1a Indo-Europeans. The Tajiks, Kirghiz, Turkmen, Uzbeks and other Central Asian ethnicities with high R1a levels and Indo-European connections all have 1-2% of U2. U2 has been found at over 2% in the Altai and at trace frequencies in Mongolia, two regions also settled by R1a (and to a lesser extent R1b). That would seem enough to prove an Indo-European connection.
We could even assume that the U2 in South Asia was brought by Indo-European invaders. The only problem is that U2 subclades in South Asia aren't the same as in Europe. Could it be that the Indo-Europeans were U2* and that U2a, U2b, U2c and U2i developed in South Asia after the IE conquest ? This isn't likely considering that U2 is about 50,000 years old. I rather believe that U2 split in Central Asia during the Palaeolithic, perhaps around the time that Y-haplogroup R split into R1a, R1b and R2, and that the South Asian subclades could be linked to the diffusion of R2, while European ones are connected to both R1a and R1b. That would also explain why U2 is also found in regions which have no or very little R1a, but some R1b, like Jordan, Southwest Europe and even North Africa.
