Here is the tree of the known subclades of haplogroup G2a. I expect that many new subclades should be identified soon. FTDNA already list these hypothetical subclades based on their STR values. However STR haplotypes do not always match SNP’s so I prefer not to list them just yet.
Armenian Highland is a mountainous region of Transcaucasia. It lies mainly in Turkey, occupies all of Armenia, and includes southern Georgia, western Azerbaijan, and northwestern Iran.
Haplogroup G is of substantial interest to prehistorians, because it has been sampled on multiple Neolithic locations from across Europe. It is certainly interesting that the estimated region of origin of haplogroup G intersects my so-called “womb of nations”, out of which I believe flowed populations after the inception of the Neolithic.
Haplogroup G, together with haplogroup J2 clades, has been associated with the spread of agriculture, especially in the European context. However, interpretations based on simple haplogroup frequency clines do not recognize underlying patterns of genetic diversification.
Haplogroup G is believed to have originated around the Middle East during the late Paleolithic, possibly as early as 30,000 years ago. At that time humans would all have been hunter-gatherers, and in most cases living in small nomadic or semi-nomadic tribes. Members of this haplogroup appear to have been closely linked to the development of early agriculture in the Levant part of the Fertile Crescent, starting 11,500 years before present.
There has so far been ancient Y-DNA analysis from only four Neolithic cultures (LBK in Germany, Remedello in Italy and Cardium Pottery in Southwest France and Spain), and all sites yielded G2a individuals, which is the strongest evidence at present that farming originated with and was spread by members of haplogroup G.
So far, the only G2a people negative for subclades downstream of P15 or L149.1 were all from the South Caucasus region. The highest genetic diversity within haplogroup G is found between the Levant and the Caucasus, another good indicator of its region of origin. It is thought that early Neolithic farmers spread from the Levant westwards to Anatolia and Europe, eastwards to Mesopotamia and South Asia, and southwards to the Arabian peninsula and North and East Africa. The domestication of goats and cows first took place in the mountainous region of eastern Anatolia, including the Caucasus and Zagros. This is probably where the roots of haplogroup G2a (and perhaps of all haplogroup G) are to be found.
Chronologically, the first hypothesis is the advance of Neolithic farmers and herders from Anatolia to Europe between 9,000 and 6,000 years ago. In this scenario the Caucasian migrants would have brought with them sheep and goats, which were domesticated south of the Caucasus arbout 12,000 years ago. This would explain why haplogroup G is more common in mountainous areas, be it in Europe or in Asia.
The geographic continuity of G2a from Anatolia to Thessaly to the Italian peninsula, Sardinia, south-central France and Iberia already suggested that G2a could be connected to the Printed-Cardium Pottery culture (5000-1500 BCE). Ancient DNA tests conducted on skeletons from a LBK site in Germany as well as a Printed-Cardium Pottery site in southern France (Languedoc-Roussilon) as well as in Spain all confirmed that Neolithic farmers in Europe belonged primarily (even exclusively if assimilated local population are omitted) to haplogroup G2a.
Nowadays G2a is found mostly in mountainous regions of Europe, for example, Cantabria (over 10%) in northern Spain, Switzerland (10%), Austria (8%), Auvergne (8%) in central France, the mountainous parts of Bohemia (5 to 10%), and Wales (4%). It may be because Caucasian farmers sought hilly terrain similar to their original homeland, perhaps well suited to the raising of goats. But it is more likely that G2a farmers escaped from Bronze-Age invaders, such as the Indo-Europeans and found shelter into the mountains.
It is most likely that G2a arrived in Europe during the Neolithic or the Bronze Age and that the Romans helped spread it around, the whole of Italy being relatively rich in G2a. Migrations within the Roman Empire probably contributed to a moderate increase of G2a northward to Gaul and Britain, Indeed, the frequency of haplogroup G decreases with the distance from the boundaries of the Roman Empire.
Haplogroup G is extremely rare Nordic and Baltic countries nowadays, despite the fact that agriculture reached those regions around the same time as Britain or Ireland. This may just be a coincidence, because the forested lowlands of northern Germany, Poland and northern Europe happen to be poor in metals and would not have attracted Bronze-Age workers from the Caucasus. North-East Europe also has a fairly modest frequency of R1b, which further reinforces the correlation between the two haplogroups.
The presumed homeland of R1b1b and Pre-Proto-Indo-European speakers is assumed to be in northern Anatolia and/or the North Caucasus. The Caucasus itself is a hotspot of haplogroup G. Therefore, it is entirely conceivable that a minority of Caucasian men belonging to haplogroup G (and perhaps also J2b) integrated the R1b community that crossed the Caucasus and established themselves on the northern and eastern shores of the Black Sea sometime between 7,000 and 5,000 BCE.
Those Proto-Indo-European would have belonged evolved to R1b1b2a1 and G2a-P303 (G2a1c2a, formerly known as G2a3b1a) before their epic conquest of Europe starting timidly in the Balkans around 4000 BCE and completed when all the Atlantic fringe from Iberia to the British Isles was settled, around 2000 BCE.
Contrarily to other branches of G2a, which are more prevalent in mountainous areas, G2a-P303 is found uniformy throughout Europe, even in Scandinavia and Russia. More importantly, G2a-P303 is also found in India, especially among the upper castes.
The combined presence of G2a-P303 across Europe and India is a very strong argument in favour of an Indo-European origin. The coalescence age of G2a-P303 also matches the time of the Indo-European expansion during the Bronze Age.
Although no basal haplogroup G-M201* chromosomes has been detected, the homeland of this haplogroup has been estimated to be somewhere nearby eastern Anatolia, Armenia or western Iran, the only areas characterized by the co-presence of deep basal branches as well as the occurrence of high sub-haplogroup diversity.
The P303 SNP defines the most frequent and widespread G sub-haplogroup. However, its sub-clades have more localized distribution with the U1-defined branch largely restricted to Near/Middle Eastern and the Caucasus, whereas L497 lineages essentially occur in Europe where they likely originated.
In contrast, the only U1 representative in Europe is the haplogroup G-M527 lineage whose distribution pattern is consistent with regions of Greek colonization. No clinal patterns were detected suggesting that the distributions are rather indicative of isolation by distance and demographic complexities.
Concerning the presence of haplogroup G in the Caucasus, one of its distinguishing features is lower haplogroup diversity in numerous populations compared with Anatolia and Armenia, implying that haplogroup G is intrusive in the Caucasus rather than autochthonous.
Another notable feature is its uneven distribution. haplogroup G is very frequent in NW Caucasus and South Caucasus, covering about 45% of the paternal lineages in both regions2 in this study. Conversely, haplogroup G is present in Northeast Caucasus only at an average frequency of 5% (range 0–19%).
Interestingly, the decrease of haplogroup G frequency towards the eastern European populations inhabiting the area adjacent to NW Caucasus, such as southern Russians and Ukrainians,18,40 is very rapid and the borderline very sharp, indicating that gene flow from the Caucasus in the northern direction has been negligible.
Armenians have less than Georgians of the haplogroup G2a but more of western European (originated in Armenian Highland) haplogroup of R1b, but the fact that there are no other populations in this world who can rival the haplogroup G subclade variety, and haplogroup G STR diversity observed in Armenians, makes it plausible that haplogroup G originated in Armenans who are natives to Caucasus and from them spread to other populations, including Georgians.
Other people who has a lot of this haplogroup, such as Georgians, Chechens, etc. lack many types of haplogroup G. Haplogroup diversity span from a low of 0.21 in Adyghes, to highs of 0.88 in Azeris (Iran) and 0.89 in eastern Anatolia and 0.90 in Armenia. We estimate that the geographic origin of haplogroup G plausibly locates somewhere nearby eastern Anatolia, Armenia or western Iran (the Armenian Highland).
The fact that Armenians have the biggest variety of haplogroup G points to the fact that Armenians are natives to the Armenian Highland were the haplogroup seems to be originated. The reason Eastern Anatolians resemble Armenians is because Eastern Anatolia is Western Armenia where according to genetic studies most people have Armenian genes (they are assimilated by Ottoman Turks) but who also mixed with invaded Central Asians, Arabs and blacks.
Azaris from Iran differ from both Persians and also Azerbaijanis with whom they share s Turkic language and resemble Armenians (of Armenia and Western Armenia/Eastern Anatolia) in regards of highest G diversity. While Armenians have no claims on Iranian Azaris or Iran it is worth mentioning that NorthWestern Iran is part of historical Armenia/Armenian Hihgland.
This one more time proves that regardless of Northern and so called Southern Azerbaijanis speaking the same language genetically and historically these are different nations. Iranian Azerbaijanis other than speaking the same Turkic language of invaders have nothing in common with Azerbaijanis. Genetically they have similarities with Armenians and culturally they are Iranians.
A group of Armenian scientists conducted a study about the origins of the Turkish people in relation to Armenians. Savak Avagian; director of Armenia’s bone marrow bank found that “Turks and Armenians were the two societies throughout the world that were genetically close to each other. Kurds are also in same genetic pool”.
The general frequency pattern of haplogroup G overall shows that the spread of haplogroup G extends over an area from southern Europe to the Near/Middle East and the Caucasus, but then decreases rapidly toward southern and Central Asia.
The rapid diminution of this haplogroup in Central/South Asia may be compatible with the relative lack of the K=7 “Southern” autosomal component in populations of the area, in contrast to a couple of Neolithic European farmers (the Tyrolean Iceman and Gok4). The Iceman himself belonged to haplogroup G, and so did individuals from Derenburg LBK, and Treilles. A couple of lineages of interest are M527 which is a low-frequency haplogroup which the authors associate with Greek colonization and the Sea Peoples, and L497 which they associate with the LBK.
Unfortunately, we currently lack ancient Y-DNA samples from West Asia. But, certainly, the samples we do have from Europe are indicative of shifts in West Asia as well, since the predominance of Y-haplogroup G in Neolithic Europe is hardly compatible with a haplogroup composition in the eastern source areas similar to today’s.
Rather, it begins to appear that there once was a (roughly speaking) western-eastern-southern distribution of the haplogroups G/R1/J2 lineages in the territory of West Asia; this would be compatible with both the Neolithic European haplogroup G dominance, the paucity of G in Central/South Asia, and its NW/S vs. NE Caucasus differentiation.
Nowadays haplogroup G is found all the way from Western Europe and Northwest Africa to Central Asia, India and East Africa, although everywhere at low frequencies (generally between 1 and 10% of the population). The only exceptions are the Caucasus region and Sardinia, where frequencies typically range from 15% to 30%.
Most Europeans belong to the G2a subclade, and most northern and western Europeans more specifically to G2a-L141.1 (or to a lower extend G2a-M406). About all G2b (L72+, formerly G2c) Europeans are Ashkenazi Jews. G2b has also been found around Afghanistan, probably as an offshoot of Neolithic farmers from the Levant.
Haplogroup G1 is found predominantly in Iran, but is also found in the Levant, among Ashkenazi Jews, and Central Asia (notably in Kazakhstan).
G2a makes up 5 to 10% of the population of Mediterranean Europe, but is fairly rare in Northern Europe. The only places where haplogroup G2 exceeds 10% of the population in Europe are Cantabria, Switzerland, the Tyrol, south-central Italy (Molise, Central and Southern Apennine), Sardinia, northern Greece (Thessaly) and Crete – all mountainous and relatively isolated regions.