Haplogroups N1a & I (mtDNA)
Geographic distribution
Haplogroup I is a fairly rare haplogroup, being found in average in 2% of Europeans and under 1% of Near Easterners. Slightly more elevated concentrations are found in Daghestan, notably among the Dargins (6.5%), Chechens (6%) and Kumyks (5.5%), as well as in isolated parts of Europe such as Mordovia (6%), Latvia (4.5%), Lithuania (3%), Finland (4%), Brittany (3%), Great Britain (4%), Ireland (3%) and Iceland (4%), but also Serbia (3.5%), Croatia (3%), Bosnia-Herzegovina (3%) and parts of Italy. Haplogroup I is absent from Lapland, the Basque country and the Maghreb, three regions that share high levels of mt-haplogroups U5 and HV0/V.
Haplogroup N1a, excluding the N1a1b2 subclade (i.e. haplogroup I), is even rarer, being found is less than 0.5% of the European population. N1a(xI) is most common in Yemen (2.5%), Saudi Arabia (2.5%), Kazakhstan (1.5%), Egypt (1%), Armenia (1%), Bosnia-Herzegovina (1%), Lithuania (1%) and Estonia (1%). There seems to be an overlap in distribution between haplogroups N1a and I in the Dinaric Alps and Baltic countries.
Distribution of mtDNA haplogroup I in Europe, North Africa and the Middle East
http://cache.eupedia.com/images/content/mtDNA-I-map.png
Origins & History
Haplogroups N1a and I have never been found in ancient samples from Paleolithic or Mesolithic Europe. N1a is thought to have originated in Southwest Asia, perhaps in the Arabian peninsula or in the southern Levant, then to have spread to the Caucasus and Europe with the diffusion of agriculture during the Neolithic period.
Neolithic farmers
The earliest evidence of N1a in Europe comes from the Early Neolithic, when it suddenly pops up in 13 of the 102 skeletons tested to date from various sites of the Linear Pottery culture (LBK) in Germany (see Adler 2012 and Brandt 2013), giving it a spectacularly high frequency of 12.75%. This may have been due to a founder effect among LBK farmers, but it is noteworthy that later Neolithic cultures in the region kept high levels of N1a compared to modern Germany. That included samples from the Rössen (9%) and Schöningen (3%) cultures, as well as the Baalberge (5%) and Salzmünde (7%) groups of the Funnelbeaker culture, spanning the whole Neolithic and early Chalcolithic periods. These German samples belonged to the N1a1a, N1a1a1 and N1a1a3 subclades.
From the time of the Corded Ware culture, representing the advance of Proto-Indo-European speakers from the Pontic Steppe of Ukraine and southern Russia, haplogroup N1a suddenly disappears from the record in Central Europe, and would never come back.
N1a was also found in the Alföld culture in Hungary, an eastern branch of the Linear Pottery culture, as well as in Megalithic France.
Nowadays N1a is also found in modern Cushitic populations of East Africa. In fact, the same N1a1a3 that was found in Neolithic Germany is now found essentially in Somalia and Ethiopia, in the Horn of Africa. This region has the world's highest frequency of Y-haplogroup T, the greatest diversity of Y-haplogroup E1b1b, and also a substantial percentage of Y-haplogroup J1, three paternal lineages thought to have been found among early agriculturalists from the Fertile Crescent alongside Y-haplogroup G2 - the four "Neolithic founder Y-DNA haplogroups". Therefore it is possible that N1a originated with Y-haplogroup J1 and/or T during the Upper Paleolithic, then spread with all four haplogroups after E1b1b and G2a converged with J1 and T in the Fertile Crescent during the Natufian period or the Pre-Pottery Neolithic.
With the expansion of agriculture from the Fertile Crescent, N1a1a (and N1a3) migrated to Anatolia, then to Europe. During that time, N1a1b expanded directly from the Fertile Crescent to the Caucasus and northern Iran, where it developed N1a1b1 (found in Iran today) and N1a1b2 (haplogroup I). In this scenario, R1b cattle herders from eastern Anatolia would have absorbed mtDNA I by intermarriages with Caucasian women on the way to the Pontic Steppe. This would have happened with other mtDNA lineages too (see maternal lineages corresponding to haplogroup R1b). Whatever the exact route and timing, haplogroup I was almost certainly found in the northwest Caucasus when the Maykop culture appeared around 3700 BCE, and would consequently have become part of the Proto-Indo-European tribes before the great migrations to Europe and Central Asia.
Haplogroup I has not been found in Neolithic remains from Europe to date. It first shows up in Chalcolithic Catalonia (c. 3500-3000 BCE) as I1c1. Interestingly it was accompanied by haplogroups U4 and W1, two typically East European lineages, which hint that the Catalan site may represent an early migration of Steppe people in western Europe.
Indo-European migrations
It is during the Late Copper Age and Early Bronze Age that haplogroup I start cropping up regularly in European remains, first in the Corded Ware culture (2.5% of all samples), associated with the expansion of Y-haplogroup R1a, but especially with the Unetice culture (13% of all samples), linked with the arrival of R1b people around modern Germany, Czechia and western Poland. Whereas N1a was exclusively found among Near Eastern Neolithic farmers, haplogroup I displays a strong connection with the Indo-European migrations. The higher frequency of I in the North Caucasus today also alludes to a link with the Maykop culture, the world's first militaristic Bronze Age culture, which was intricately connected with the Yamna culture of the Pontic Steppe (see R1b history).
Lineages found among the Unetice culture belonged to the I1, I1a1 and I3a subclades, I1a1 being the most prevalent among them. The oldest known R1b1b2 sample at present is an individual from the late Corded Ware or pre-Unetice culture (2600–2500 BCE) in eastern Germany who happened to belong to mt-haplogroup I1a1.
Haplogroup I was also found in Scythian remains in Siberia (I4 subclade, Keyser et al. 2009) and in southern Russia (I3 subclade, Der Sarkissian et al. 2011).
Another way to determine whether a particular lineage could have been spread by the Indo-European migration is to compare their modern distribution in regions historically settled by the Indo-Europeans, which besides Europe also comprises most of Central Asia, parts of Siberia (notably the Altai), as well as South Asia from Iran to western India. Haplogroup I is indeed present in all these regions. Unfortunately data about specific subclades is still sparse, but I1a appears to be the most common form of I in Uzbekistan and Turkmenistan, the two Central Asian countries with the highest percentages of R1b. I1a is also common in central and eastern Europe, in the Caucasus and in the British isles.
Haplogroup I2 is found in most of northern Europe, but also in the Caucasus, in Siberia and among the Pasiegos of Cantabria in northern Spain, who has possess other typically Indo-European maternal lineages like H6, J1b1a, T1a1a, U2e, U4 and U5a1a and surprisingly high levels of Y-haplogroup R1a (see Maca-Meyer et al. 2003). I3 is found mostly in countries with high percentages of R1b in northwestern Europe, and its presence in the Unetice culture and among ancient Scythians confirm an Indo-European origin. I4a is scattered around all Europe, but is also found around the Black Sea, the North Caucasus, Iran and Siberia, all regions settled by the Indo-Europeans.
Other subclades
Three I5 samples were identified in a site from the early Minoan civilization by Hughey et al. 2013. The fact that the Minoans were a pre-Indo-European Greek culture casts doubt on the Indo-European origin of I5. Nevertheless, its modern distribution ranges from the North Caucasus to central and western Europe, argues in favour of an Indo-European dispersal. The case of I5 cannot be settled in light of the present data.
On the other hand, the modern distributions of I4b, so far found only in Iran, I6, found in northern Iran, Turkey and Sicily, and I7, found in Armenia and Mesopotamia, do not suggest a Steppe connection. The pre-Indo-European development of haplogroup I in the Caucasus can explain why subclades like I6 and I7 aren't associated with the Indo-Europeans. These were probably lineages from the South Caucasus, which became part of the Kura-Araxes culture during the Early Bronze Age, and expanded to Anatolia and northern Mesopotamia. Kura-Araxes men are thought to have belonged essentially to Y-haplogroup G2a and J2, with a minority of J1 and T. After centuries of intermingling with other Anatolian people, they may have indirectly become the ancestors of the ancient Greek people. In the Classical Greek Antiquity, I5 and I6 would have been spread to Magna Graecia (southern Italy), especially southern Sicily and Apulia, which were Doric colonies with direct links to Crete.
Subclades
N1a
N1a1'2
N1a1
N1a1a: found in the North Caucasus (Kabardia) and Yemen
N1a1a1: found in Neolithic Germany
N1a1a1a
N1a1a1a1: found in Russia
N1a1a1a2: found in Siberia (Buryat)
N1a1a1a3
N1a1a1b
N1a1a2
N1a1a3: found in Somalia, Ethiopia, and Neolithic Germany
N1a1b
N1a1b1: found in Iran and the Arabian peninsula
I (aka N1a1b2)
I1
I1a: found in most of Europe and Central Asia, as well as in North Caucasus, Siberia, Iran, Pakistan and India
I1a1
I1a1a: found in north-east Europe and Siberia
I1a1b: found in Scandinavia, Germany and the British Isles
I1a1c: found in north-east Europe and Norway
I1a1d: found in the British Isles
I1a1e: found in the British Isles
I1b: found in the Levant, around the Caucasus, in Poland, Sweden and India
I1c: found in central and eastern Europe and in Siberia
I1c1: found in central and eastern Europe
I1c1a: found among Ashkenazi Jews
I1d: found in Italy
I1e: found in India
I2: found in northern and central Europe, Anatolia, the North Caucasus and Azerbaijan
I2a: found in northern and central Europe, and in Siberia
I2b: found in Finland
I2c: found in Britain
I2d: found in northern Europe
I2e: found in Germany and England
I3: found mostly in northwestern Europe
I3a: found mostly in Celtic and Germanic countries
I3b: found in Poland and Ireland
I3c: found in Ireland
I3d
I4
I4a: found in north-west and central Europe, around the Black Sea, in the North Caucasus, Armenia, Iran and Siberia
I4a1: found in Britain, European Russia and Siberia
I4a2: found in Finland
I4b: found in northern Iran
I5: found in the North Caucasus (North Ossetia)
I5a: found in southern and central Europe, in Turkey and in the Arabian peninsula
I5a1: found in Iberia and France
I5a2: found in Germany
I5a3: found in Germany and Turkey
I5a4: found in Romania and southern Russia
I5b: found in Italy
I5b1: found in Iran
I5c
I5c1: found in Italy, Poland, Germany and England
I6: found in Turkey
I6a: found in Italy (Sicily)
I6b: found in Turkey and Iran
I7: found in Armenia and Kuwait
N1a2: found in India
N1a3: found in Belarus
N1a3a: found in Romania and Saudi Arabia
N1a3a1: found in Russia
N1a3a2: found in Italy and Kuwait
N1a3a3: found in Cyprus and Russia
Source: http://www.eupedia.com/europe/Haplogroup_I_mtDNA.shtml
