Sunday, March 20, 2016

R1b DNA...

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Haplogroup R1b (Y-DNA)

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Haplogroup R1b (Y-DNA) - Eupedia
Author: Maciamo.
Last update July 2015 (updated 'conquest of Western Europe')

Geographic distribution

Distribution of haplogroup R1b in Europe
Distribution of haplogroup R1b in Europe
R1b is the most common haplogroup in Western Europe, reaching over 80% of the population in Ireland, the Scottish Highlands, western Wales, the Atlantic fringe of France, the Basque country and Catalonia. It is also common in Anatolia and around the Caucasus, in parts of Russia and in Central and South Asia. Besides the Atlantic and North Sea coast of Europe, hotspots include the Po valley in north-central Italy (over 70%), Armenia (35%), the Bashkirs of the Urals region of Russia (50%), Turkmenistan (over 35%), the Hazara people of Afghanistan (35%), the Uyghurs of North-West China (20%) and the Newars of Nepal (11%). R1b-V88, a subclade specific to sub-Saharan Africa, is found in 60 to 95% of men in northern Cameroon.

Distribution map of haplogroup R1b in the Old World

Distribution map of haplogroup R1b in the Old World (Eurasia and Africa) - Eupedia


Here is a schematic tree of the principal R1b subclades. Please refer to the International Society of Genetic Genealogy (ISOGG) for the full tree with all the SNP's and the latest nomenclature.
Phylogenetic tree of haplogroup R1b (Y-DNA) - Eupedia

Click on the trees below to enlarge

Phylogenetic tree of haplogroup R1b-L21/M529 (Y-DNA) - Eupedia
Phylogenetic tree of haplogroup R1b-DF27/S250 (Y-DNA) - Eupedia
Phylogenetic tree of haplogroup R1b-S28/U152 (Y-DNA) - Eupedia
Phylogenetic tree of haplogroup R1b-S21/U106 (Y-DNA) - Eupedia

Origins & History

Paleolithic mammoth hunters

Haplogroup R* originated in North Asia just before the Last Glacial Maximum (26,500-19,000 years ago). This haplogroup has been identified in the remains of a 24,000 year-old boy from the Altai region, in south-central Siberia (Raghavan et al. 2013). This individual belonged to a tribe of mammoth hunters that may have roamed across Siberia and parts of Europe during the Paleolithic. Autosomally this Paleolithic population appears to have contributed mostly to the ancestry of modern Europeans and South Asians, the two regions where haplogroup R also happens to be the most common nowadays (R1b in Western Europe, R1a in Eastern Europe, Central and South Asia, and R2 in South Asia).
The oldest forms of R1b (M343, P25, L389) are found dispersed at very low frequencies from Western Europe to India, a vast region where could have roamed the nomadic R1b hunter-gatherers during the Ice Age. The three main branches of R1b1 (R1b1a, R1b1b, R1b1c) all seem to have stemmed from the Middle East. The southern branch, R1b1c (V88), is found mostly in the Levant and Africa. The northern branch, R1b1a (P297), seems to have originated around the Caucasus, eastern Anatolia or northern Mesopotamia, then to have crossed over the Caucasus, from where they would have invaded Europe and Central Asia. R1b1b (M335) has only been found in Anatolia.

Neolithic cattle herders

It has been hypothetised that R1b people (perhaps alongside neighbouring J2 tribes) were the first to domesticate cattle in northern Mesopotamia some 10,500 years ago. R1b tribes descended from mammoth hunters, and when mammoths went extinct, they started hunting other large game such as bisons and aurochs. With the increase of the human population in the Fertile Crescent from the beginning of the Neolithic (starting 12,000 years ago), selective hunting and culling of herds started replacing indiscriminate killing of wild animals. The increased involvement of humans in the life of aurochs, wild boars and goats led to their progressive taming. Cattle herders probably maintained a nomadic or semi-nomadic existence, while other people in the Fertile Crescent (presumably represented by haplogroups E1b1b, G and T) settled down to cultivate the land or keep smaller domesticates.
The analysis of bovine DNA has revealed that all the taurine cattle (Bos taurus) alive today descend from a population of only 80 aurochs. The earliest evidence of cattle domestication dates from circa 8,500 BCE in the Pre-Pottery Neolithic cultures in the Taurus Mountains. The two oldest archaeological sites showing signs of cattle domestication are the villages of Çayönü Tepesi in southeastern Turkey and Dja'de el-Mughara in northern Iraq, two sites only 250 km away from each others. This is presumably the area from which R1b lineages started expanding - or in other words the "original homeland" of R1b.
The early R1b cattle herders would have split in at least three groups. One branch (M335) remained in Anatolia, but judging from its extreme rarity today wasn't very successful, perhaps due to the heavy competition with other Neolithic populations in Anatolia, or to the scarcity of pastures in this mountainous environment. A second branch migrated south to the Levant, where it became the V88 branch. Some of them searched for new lands south in Africa, first in Egypt, then colonising most of northern Africa, from the Mediterranean coast to the Sahel. The third branch (P297), crossed the Caucasus into the vast Pontic-Caspian Steppe, which provided ideal grazing grounds for cattle. They split into two factions: R1b1a1 (M73), which went east along the Caspian Sea to Central Asia, and R1b1a2 (M269), which at first remained in the North Caucasus and the Pontic Steppe between the Dnieper and the Volga. It is not yet clear whether M73 actually migrated across the Caucasus and reached Central Asia via Kazakhstan, or if it went south through Iran and Turkmenistan. In the latter case, M73 might not be an Indo-European branch of R1b, just like V88 and M335.
R1b-M269 (the most common form in Europe) is closely associated with the diffusion of Indo-European languages, as attested by its presence in all regions of the world where Indo-European languages were spoken in ancient times, from the Atlantic coast of Europe to the Indian subcontinent, which comprised almost all Europe (except Finland, Sardinia and Bosnia-Herzegovina), Anatolia, Armenia, European Russia, southern Siberia, many pockets around Central Asia (notably in Xinjiang, Turkmenistan, Tajikistan and Afghanistan), without forgetting Iran, Pakistan, northern India and Nepal. The history of R1b and R1a are intricately connected to each others.

The Levantine & African branch of R1b (V88)

Like its northern counterpart (R1b-M269), R1b-V88 is associated with the domestication of cattle in northern Mesopotamia. Both branches of R1b probably split soon after cattle were domesticated, approximately 10,500 years ago (8,500 BCE). R1b-V88 migrated south towards the Levant and Egypt. The migration of R1b people can be followed archeologically through the presence of domesticated cattle, which appear in central Syria around 8,000-7,500 BCE (late Mureybet period), then in the Southern Levant and Egypt around 7,000-6,500 BCE (e.g. at Nabta Playa and Bir Kiseiba). Cattle herders subsequently spread across most of northern and eastern Africa. The Sahara desert would have been more humid during the Neolithic Subpluvial period (c. 7250-3250 BCE), and would have been a vast savannah full of grass, an ideal environment for cattle herding.
Evidence of cow herding during the Neolithic has shown up at Uan Muhuggiag in central Libya around 5500 BCE, at the Capeletti Cave in northern Algeria around 4500 BCE. But the most compelling evidence that R1b people related to modern Europeans once roamed the Sahara is to be found at Tassili n'Ajjer in southern Algeria, a site famous pyroglyphs (rock art) dating from the Neolithic era. Some painting dating from around 3000 BCE depict fair-skinned and blond or auburn haired women riding on cows.
After reaching the Maghreb, R1b-V88 cattle herders could have crossed the Strait of Gibraltar to Iberia, probably accompanied by G2 farmers, J1 and T1a goat herders and native Maghreban E-M81 lineages. These Maghreban Neolithic farmers/herders could have been the ones who established the Almagra Pottery culture in Andalusia in the 6th millennium BCE.
Nowadays small percentages (1 to 4%) of R1b-V88 are found in the Levant, among the Lebanese, the Druze, and the Jews, and almost in every country in Africa north of the equator. Higher frequency in Egypt (5%), among Berbers from the Egypt-Libya border (23%), among the Sudanese Copts (15%), the Hausa people of Sudan (40%), the the Fulani people of the Sahel (54% in Niger and Cameroon), and Chadic tribes of northern Nigeria and northern Cameroon (especially among the Kirdi), where it is observed at a frequency ranging from 30% to 95% of men. According to Cruciani et al. (2010) R1b-V88 would have crossed the Sahara between 9,200 and 5,600 years ago, and is most probably associated with the diffusion of Chadic languages, a branch of the Afroasiatic languages. V88 would have migrated from Egypt to Sudan, then expanded along the Sahel until northern Cameroon and Nigeria. However, R1b-V88 is not only present among Chadic speakers, but also among Senegambian speakers (Fula-Hausa) and Semitic speakers (Berbers, Arabs).
R1b-V88 is found among the native populations of Rwanda, South Africa, Namibia, Angola, Congo, Gabon, Equatorial Guinea, Ivory Coast, Guinea-Bissau. The wide distribution of V88 in all parts of Africa, its incidence among herding tribes, and the coalescence age of the haplogroup all support a Neolithic dispersal. In any case, a later migration out of Egypt would be improbable since it would have brought haplogroups that came to Egypt during the Bronze Age, such as J1, J2, R1a or R1b-L23.
The maternal lineages associated with the spread of R1b-V88 in Africa are mtDNA haplogroups J1b, U5 and V, and perhaps also U3 and some H subclades (=> see Retracing the mtDNA haplogroups of the original R1b people).

The North Caucasus and the Pontic-Caspian steppe : the Indo-European link

Modern linguists have placed the Proto-Indo-European homeland in the Pontic-Caspian Steppe, a distinct geographic and archeological region extending from the Danube estuary to the Ural mountains to the east and North Caucasus to the south. The Neolithic, Eneolithic and early Bronze Age cultures in Pontic-Caspian steppe has been called the Kurgan culture(4200-2200 BCE) by Marija Gimbutas, due to the lasting practice of burying the deads under mounds ("kurgan") among the succession of cultures in that region. It is now known that kurgan-type burials only date from the 4th millenium BCE and almost certainly originated south of the Caucasus. The genetic diversity of R1b being greater around eastern Anatolia, it is hard to deny that R1b evolved there before entering the steppe world. 
Horses were first domesticated around 4600 BCE in the Caspian Steppe, perhaps somewhere around the Don or the lower Volga, and soon became a defining element of steppe culture. Nevertheless it is unlikely that R1b was already present in the eastern steppes at the time, so the domestication of the horse should be attributed to the indigenous R1a people.
It is not yet entirely clear when R1b crossed over from eastern Anatolia to the Pontic-Caspian steppe. This might have happened with the appearance of the Dnieper-Donets culture (c. 5100-4300 BCE). This was the first truly Neolithic society in the Pontic-Caspian Steppe. Domesticated animals (cattle, sheep and goats) were herded throughout the steppes and funeral rituals were elaborate. Sheep wool would play an important role in Indo-European society, notably in the Celtic and Germanic (R1b branches of the Indo-Europeans) clothing traditions up to this day. However, many elements indicate a continuity in the Dnieper-Donets culture with the previous Mesolithic hunter-gatherers, and at the same time an influence from the Balkans and Carpathians, with regular imports of pottery and copper objects. It is therefore more likely that Dnieper-Donets marked the transition of indigenous R1a and/or I2a1b people to early agriculture, perhaps with an influx of Near Eastern farmers from 'Old Europe'. Mitochondrial DNA sequences from Dnieper-Donets culture showed clear similarities with those of the Cucuteni-Trypillian culture in the Carpathians (haplogroups H, T and U3).
The first clearly Proto-Indo-European culture was Sredny Stog (4600-3900 BCE), when small kurgan burials begin to appear, with the distinctive posturing of the dead on the back with knees raised and oriented toward the northeast, which would be found in later steppe cultures as well. There is evidence of population blending from the variety of skull shapes. Towards the end of the 5th millennium, an elite starts to develop with cattle, horses and copper used as status symbols.
Another migration across the Caucasus happened shortly before 3700 BCE, when the Maykop culture, the world's first Bronze Age society, suddenly materialized in the north-west Caucasus, apparently out of nowhere. The origins of Maykop are still uncertain, but archeologists have linked it to contemporary Chalcolithic cultures in Assyria and western Iran. Archeology also shows a clear diffusion of bronze working and kurgan-type burials from the Maykop culture to the Pontic Steppe, where the Yamna culture developed soon afterwards (from 3500 BCE). Kurgan (a.k.a. tumulus) burials would become a dominant feature of ancient Indo-European societies and were widely used by the Celts, Romans, Germanic tribes, and Scythians, among others.
The Yamna period (3500-2500 BCE) is the most important one in the creation of Indo-European culture and society. Middle Eastern R1b people had been living and blending to some extent with the local R1a foragers and herders for over a millennium, perhaps even two or three. The close cultural contact and interactions between R1a and R1b people all over the Pontic-Caspian Steppe resulted in the creation of a common vernacular, a new lingua franca, which linguists have called Proto-Indo-European (PIE). It is pointless to try to assign another region of origin to the PIE language. Linguistic similarities exist between PIE and Caucasian and Hurrian languages in the Middle East on the one hand, and Uralic languages in the Volga-Ural region on the other hand, which makes the Pontic Steppe the perfect intermediary region.
During the Yamna period cattle and sheep herders adopted wagons to transport their food and tents, which allowed them to move deeper into the steppe, giving rise to a new mobile lifestyle that would eventually lead to the great Indo-European migrations. This type of mass migration in which whole tribes moved with the help of wagons was still common in Gaul at the time of Julius Caesar, and among Germanic peoples in the late Antiquity.
The Yamna horizon was not a single, unified culture. In the south, along the northern shores of the Black Sea coast until the the north-west Caucasus, was a region of open steppe, expanding eastward until the Caspian Sea, Siberia and Mongolia (the Eurasian Steppe). The western section, between the Don and Dniester Rivers (and later the Danube), was the one most densely settled by R1b people, with only a minority of R1a people (5-10%). The eastern section, in the Volga basin until the Ural mountains, was inhabited by R1a people with a substantial minority of R1b people (whose descendants can be found among the Bashkirs, Turkmans, Uyghurs and Hazaras, among others). The northern part of the Yamna horizon was forest-steppe occupied by R1a people, also joined by a small minority of R1b (judging from modern Russians and Belarussians, the frequency of R1b was from seven to nine times less lower than R1a). The western branch would migrate to the Balkans and Greece, then to central and Western Europe, and back to their ancestral Anatolia in successive waves (Hittites, Phrygians, Armenians, etc.). The eastern branch would migrate to Central Asia, Xinjiang, Siberia, and South Asia (Iran, Pakistan, India). The northern branch would evolve into the Corded Ware culture and disperse around the Baltic, Poland, Germany and Scandinavia.

The Maykop culture, the R1b link to the steppe ?

The Maykop culture (3700-2500 BCE) in the north-west Caucasus was culturally speaking a sort of southern extension of the Yamna horizon. Although not generally considered part of the Pontic-Caspian steppe culture due to its geography, the North Caucasus had close links with the steppes, as attested by numerous ceramics, gold, copper and bronze weapons and jewelry in the contemporaneous cultures of Mikhaylovka, Sredny Stog and Kemi Oba. The link between the northern Black Sea coast and the North Caucasus is older than the Maykop period. Its predecessor, the Svobodnoe culture (4400-3700 BCE), already had links to the Suvorovo-Novodanilovka and early Sredny Stog cultures. The even older Nalchik settlement (5000-4500 BCE) in the North Caucasus displayed a similar culture as Khvalynsk on the Volga. This may be the period when R1b started interracting and blending with the R1a population of the steppes.
The Yamna and Maykop people both used kurgan burials, placing their deads in a supine position with raised knees and oriented in a north-east/south-west axis. Graves were sprinkled with red ochre on the floor, and sacrificed domestic animal buried alongside humans. They also had in common horses, wagons, a heavily cattle-based economy with a minority of sheep kept for their wool, use of copper/bronze battle-axes (both hammer-axes and sleeved axes) and tanged daggers. In fact, the oldest wagons and bronze artefacts are found in the North Caucasus, and appe