Haplogroup R1b

Haplogroup R1b, previously known as Hg1 and Eu18, is a human Y-chromosome haplogroup.
It is the most frequently occurring paternal lineage in Western Europe, as well as some parts of Russia and across the Sahel in Central Africa, namely: Cameroon, Chad, Guinea, Mauritania, Mali, Niger, Nigeria and Senegal.
The clade is also present at lower frequencies throughout Eastern Europe, Western Asia, Central Asia as well as parts of North Africa, South Asia and Central Asia.
R1b has two primary branches: R1b1-L754 and R1b2-PH155. Where R1b1-L754 has two major subclades: R1b1a1b-M269, which predominates in Western Europe, and R1b1a2-V88, which is today common in parts of Central Africa. The other branch, R1b2-PH155, is so rare and widely dispersed that it is difficult to draw any conclusions about its origins. It has been found in Bahrain, India, Nepal, Bhutan, Ladakh, Tajikistan, Turkey, and Western China.
According to ancient DNA studies, most R1a and R1b lineages would have expanded from the Pontic Steppe along with the Indo-European languages.

Origin and dispersal

The age of R1 was estimated by Tatiana Karafet et al. at between 12,500 and 25,700 BP, and most probably occurred about 18,500 years ago. Since the earliest known example has been dated at circa 14,000 BP, and belongs to R1b1, R1b must have arisen relatively soon after the emergence of R1.
Early human remains found to carry R1b include:

Villabruna 1, a Western Hunter-Gatherer, found in an Epigravettian culture setting in the Cismon valley, who lived circa 14000 BP and belonged to R1b1a.
Several males of the Iron Gates Mesolithic in the Balkans buried between 11200 and 8200 BP carried R1b1a1a. These individuals were determined to be largely of WHG ancestry, with slight Eastern Hunter-Gatherer admixture.
Several males of the Mesolithic Kunda culture and Neolithic Narva culture buried in the Zvejnieki burial ground in modern-day Latvia c. 9500–6000 BP carried R1b1b. These individuals were determined to be largely of WHG ancestry, with slight EHG admixture.
Several Mesolithic and Neolithic males buried at Deriivka and Vasil'evka in modern-day Ukraine c. 9500-7000 BP carried R1b1a. These individuals were largely of EHG ancestry, with significant WHG admixture.
A WHG male buried at Ostrovul Corbului, Romania c. 8700 BP carried R1b1c.
A male buried at Lepenski Vir, Serbia c. 8200-7900 BP carried R1b1a.
An EHG buried near Samara, Russia 7500 BP carried R1b1a1a.
An Eneolithic male buried at Khvalynsk, Russia c. 7200-6000 BP carried R1b1a.
A Neolithic male buried at Els Trocs, Spain c. 7178-7066 BP, who may have belonged to the Epi-Cardial culture, was found to be a carrier of R1b1.
A Late Chalcolithic male buried in Smyadovo, Bulgaria c. 6500 BP carried R1b1a.
An Early Copper Age male buried in Cannas di Sotto, Carbonia, Sardinia c. 6450 BP carried R1b1b2.
A male of the Baalberge group in Central Europe buried c. 5600 BP carried R1b1a.
A male of the Botai culture in Central Asia buried c. 5500 BP carried R1b1a1.
7 males that were tested of the Yamnaya culture were all found to belong to the M269 subclade of haplogroup R1b.

R1b is a subclade within the "macro-haplogroup" K, the most common group of human male lines outside of Africa. K is believed to have originated in Asia. Karafet T. et al. suggested that a "rapid diversification process of K-M526 likely occurred in Southeast Asia, with subsequent westward expansions of the ancestors of haplogroups R and Q". However the oldest example of R* has been found in an Ancient North Eurasian sample from Siberia, and its precursor P1 has been found in another Ancient North Eurasian sample from northern Siberia dating from c. 31,600 years ago.
Three genetic studies in 2015 gave support to the Kurgan hypothesis of Marija Gimbutas regarding the Proto-Indo-European homeland. According to those studies, haplogroups R1b-M269 and R1a, now the most common in Europe would have expanded from the West Eurasian Steppe, along with the Indo-European languages; they also detected an autosomal component present in modern Europeans which was not present in Neolithic Europeans, which would have been introduced with paternal lineages R1b and R1a, as well as Indo-European languages.
File:IE expansion.png|thumb|right|Map of Indo-European migrations from c. 4000 to 1000 BC according to the Kurgan model. The magenta area corresponds to the assumed urheimat.
Analysis of ancient Y-DNA from the remains from early Neolithic Central and North European Linear Pottery culture settlements have not yet found males belonging to haplogroup R1b-M269. Olalde et al. trace the spread of haplogroup R1b-M269 in western Europe, particularly Britain, to the spread of the Beaker culture, with a sudden appearance of many R1b-M269 haplogroups in Western Europe ca. 5000–4500 years BP during the early Bronze Age.

Structure

External phylogeny of R1b

The broader haplogroup R is a primary subclade of haplogroup P1 itself a primary branch of P, which is also known as haplogroup K2b2. R-M207 is therefore a secondary branch of K2b, and a direct descendant of K2.
;Phylogeny within K2b

P P295/PF5866/S8.
* P1 M45
** Q M242
** R M207
*** R1
**** R1a
**** '''R1b'''
Internal structure of R1b

Names such as R1b, R1b1 and so on are phylogenetic names which make clear their place within the branching of haplogroups, or the phylogenetic tree. An alternative way of naming the same haplogroups and subclades refers to their defining SNP mutations: for example, R-M343 is equivalent to R1b. Phylogenetic names change with new discoveries and SNP-based names are consequently reclassified within the phylogenetic tree. In some cases, an SNP is found to be unreliable as a defining mutation and an SNP-based name is removed completely. For example, before 2005, R1b was synonymous with R-P25, which was later reclassified as R1b1; in 2016, R-P25 was removed completely as a defining SNP, due to a significant rate of back-mutation.

Geographical distribution

R1b* (R-M343*)

No confirmed cases of R1b* – that is R1b, also known as R-M343 – have been reported in peer-reviewed literature.
;R-M343
In early research, because R-M269, R-M73 and R-V88 are by far the most common forms of R1b, examples of R1b were sometimes assumed to signify basal examples of "R1b*". However, while the paragroup R-M343 is rare, it does not preclude membership of rare and/or subsequently-discovered, relatively basal subclades of R1b, such as R-L278*, R-L389*, R-P297*, R-V1636 or R-PH155.
The population believed to have the highest proportion of R-M343 are the Kurds of southeastern Kazakhstan with 13%. However, more recently, a large study of Y-chromosome variation in Iran, revealed R-M343 as high as 4.3% among Iranian sub-populations.
It remains a possibility that some, or even most of these cases, may be R-L278*, R-L389*, R-P297*, R-V1636, R-PH155, R1b*, R1a*, an otherwise undocumented branch of R1, and/or back-mutations of a marker, from a positive to a negative ancestral state, and hence constitute undocumented subclades of R1b.
A compilation of previous studies regarding the distribution of R1b can be found in Cruciani et al.. It is summarised in the table following.

R1b (R-L278)

R-L278 among modern men falls into the R-L754 and R-PH155 subclades, though it is possible some very rare R-L278* may exist as not all examples have been tested for both branches. Examples may also exist in ancient DNA, though due to poor quality it is often impossible to tell whether or not the ancients carried the mutations that define subclades.
Some examples described in older articles, for example two found in Turkey, are now thought to be mostly in the more recently discovered sub-clade R1b1b. Most examples of R1b therefore fall into subclades R1b1b or R1b1a. Cruciani et al. in the large 2010 study found 3 cases amongst 1173 Italians, 1 out of 328 West Asians and 1 out of 156 East Asians. Varzari found 3 cases in Ukraine, in a study of 322 people from the Dniester–Carpathian Mountains region, who were P25 positive, but M269 negative. Cases from older studies are mainly from Africa, the Middle East or Mediterranean, and are discussed below as probable cases of R1b1b.

R1b1 (R-L754)

R-L754 contains the vast majority of R1b. The only known example of R-L754* is also the earliest known individual to carry R1b: "Villabruna 1", who lived circa 14,000 years BP. Villabruna 1 belonged to the Epigravettian culture.

R1b1a (R-L389)

R-L389, also known as R1b1a, contains the very common subclade R-P297 and the rare subclade R-V1636. It is unknown whether all previously reported R-L389* belong to R-V1636 or not.

R1b1a1 (R-P297)

The SNP marker P297 was recognised in 2008 as ancestral to the significant subclades M73 and M269, combining them into one cluster. This had been given the phylogenetic name R1b1a1a.
A majority of Eurasian R1b falls within this subclade, representing a very large modern population. Although P297 itself has not yet been much tested for, the same population has been relatively well studied in terms of other markers. Therefore, the branching within this clade can be explained in relatively high detail below.

R1b1a1a (R-M73)

R-M73, also known as R1b1a1a, is a Y-chromosome haplogroup that is a subclade of the broader R1b lineage. This haplogroup is defined by the M73 single nucleotide polymorphism mutation. The two largest subclades are R-M478 and R-BY15590.
R-M73 is primarily found in populations across Central Asia, parts of Siberia, the Caucasus region, and to a lesser extent in the Middle East and South Asia. It is particularly prevalent among certain indigenous populations of the Altai region in Siberia.
R1b has been found in 35.3 % of Eushta sub-group of Siberian Tatars.
Malyarchuk et al. found R-M73 in 13.2% of Shors, 11.4% of Teleuts, 3.3% of Kalmyks, 3.1% of Khakassians, 1.9% of Tuvinians, and 1.1% of Altaians. The Kalmyks, Tuvinians, and Altaian belong to a Y-STR cluster marked by DYS390=19, DYS389=14-16, and DYS385=13-13.
Dulik et al. found R-M73 in 35.3% of a sample of the Kumandin of the Altai Republic in Russia. Three of these six Kumandins share an identical 15-loci Y-STR haplotype, and another two differ only at the DYS458 locus, having DYS458=18 instead of DYS458=17. This pair of Kumandin R-M73 haplotypes resembles the haplotypes of two Kalmyks, two Tuvinians, and one Altaian whose Y-DNA has been analyzed by Malyarchuk et al.. The remaining R-M73 Kumandin has a Y-STR haplotype that is starkly different from the haplotypes of the other R-M73 Kumandins, resembling instead the haplotypes of five Shors, five Teleuts, and two Khakassians.
While early research into R-M73 claimed that it was significantly represented among the Hazara of Afghanistan and the Bashkirs of the Ural Mountains, this has apparently been overturned. For example, supporting material from a 2010 study by Behar et al. suggested that Sengupta et al. might have misidentified Hazara individuals, who instead belonged to "PQR2" as opposed to "R." However, the assignment of these Hazaras' Y-DNA to the "PQR2" category by Behar et al. is probably ascribable to the habit that was popular for a while of labeling R-M269 as "R1b" or "R," with any members of R-M343 being placed in a polyphyletic, catch-all "R*" or "P" category. Myres et al., Di Cristofaro et al., and Lippold et al. all agree that the Y-DNA of 32% of the HGDP sample of Pakistani Hazara should belong to haplogroup R-M478/M73. Likewise, most Bashkir males have been found to belong to U-152 and some, mostly from southeastern Bashkortostan, belonged to Haplogroup Q-M25 rather than R1b; contra this, Myres et al. found a high frequency of R-M73 among their sample of Bashkirs from southeast Bashkortostan, in agreement with the earlier study of Bashkirs. Besides the high frequency of R-M73 in southeastern Bashkirs, Myres et al. also reported finding R-M73 in the following samples: 10.3% of Balkars from the northwest Caucasus, 9.4% of the HGDP samples from northern Pakistan, 5.8% of Karachays from the northwest Caucasus, 2.6% of Tatars from Bashkortostan, 1.9% of Bashkirs from southwest Bashkortostan, 1.5% of Megrels from the south Caucasus, 1.4% of Bashkirs from north Bashkortostan, 1.3% of Tatars from Kazan, 1.1% of a sample from Cappadocia, Turkey, 0.7% of Kabardians from the northwest Caucasus, 0.6% of a pool of samples from Turkey, and 0.38% of Russians from Central Russia.
Besides the aforementioned Pakistani Hazaras, Di Cristofaro et al. found R-M478/M73 in 11.1% of Mongols from central Mongolia, 5.0% of Kyrgyz from southwest Kyrgyzstan, 4.3% of Mongols from southeast Mongolia, 4.3% of Uzbeks from Jawzjan, Afghanistan, 3.7% of Iranians from Gilan, 2.5% of Kyrgyz from central Kyrgyzstan, 2.1% of Mongols from northwest Mongolia, and 1.4% of Turkmens from Jawzjan, Afghanistan. The Mongols as well as the individual from southwest Kyrgyzstan, the individual from Gilan, and one of the Uzbeks from Jawzjan belong to the same Y-STR haplotype cluster as five of six Kumandin members of R-M73 studied by Dulik et al.. This cluster's most distinctive Y-STR value is DYS390=19.
Karafet et al. found R-M73 in 37.5% of a sample of Teleuts from Bekovo, Kemerovo oblast, 4.5% of a sample of Uyghurs from Xinjiang Uyghur Autonomous Region, 3.4% of a sample of Kazakhs from Kazakhstan, 2.3% of a sample of Selkups, 2.3% of a sample of Turkmens from Turkmenistan, and 0.7% of a sample of Iranians from Iran. Four of these individuals appear to belong to the aforementioned cluster marked by DYS390=19 ; the Teleut and the Uyghur also share the modal values at the DYS385 and the DYS389 loci. The Iranian differs from the modal for this cluster by having 13-16 at DYS389 instead of 14-16. The Kazakh differs from the modal by having 13–14 at DYS385 instead of 13-13. The other fourteen Teleuts and the three Selkups appear to belong to the Teleut-Shor-Khakassian R-M73 cluster from the data set of Malyarchuk et al. ; this cluster has the modal values of DYS390=22, DYS385=13-16, and DYS389=13-17.
A Kazakhstani paper published in 2017 found haplogroup R1b-M478 Y-DNA in 3.17% of a sample of Kazakhs from Kazakhstan, with this haplogroup being observed with greater than average frequency among members of the Qypshaq, Ysty, Qongyrat, Oshaqty, Kerey, and Jetyru tribes. A Chinese paper published in 2018 found haplogroup R1b-M478 Y-DNA in 9.2% of a sample of Dolan Uyghurs from Horiqol township, Awat County, Xinjiang.