Haplogroup K2b (Y-DNA)

Haplogroup K2b (P331), also known as MPS ^[2] is a human y-chromosome haplogroup that is thought to be less than 3,000 years younger than K, and less than 10,000 years younger than F, meaning it probably is around 50,000 years old, according to the age estimates of Tatiana Karafet et al. 2014.^[1]

The basal paragroup K2b* has not been identified among living males or ancient remains. (One previously reported sample, dated at 3,000 years before present, has since been reclassified as R1a – an individual known as RISE94, from Viby in Sweden.)

K2b1 (P397/P399) known previously as Haplogroup MS, and Haplogroup P (P-P295), also known as K2b2 are the only primary clades of K2b. The population geneticist Tatiana Karafet and other researchers (2014) point out that K2b1, its subclades and P* are virtually restricted geographically to South East Asia and Oceania.^[1] Whereas, in a striking contrast, P1 (P-M45) – the sole primary subclade of P* – and the primary clades Q and R, now make up: "the majority of paternal lineages in Europe, Central Asia and the Americas". According to Karafet et. al., the estimated dates for the branching of K, K2, K2b and P point to a "rapid diversification" within K2 "that likely occurred in Southeast Asia", with subsequent "westward expansions" of P*, P1, Q and R.^[1]

Phylogenetic structure

• K2b (P331), also known as MPS.
  • K2b1 (P397, P399), similar to the previous Haplogroup MS.
    • K2b1a (CTS5650/F3744/P405) – descendant subclades include Haplogroup S, also known as K2b1a4.
    • K2b1b (P336)
    • K2b1c (P378)
    • Haplogroup M (P256) – also known as K2b1d.
  • Haplogroup P (P295/PF5866/S8) – also known as K2b2.
    • P1 (M45) – also known as K2b2a; descendant subclades include the major haplogroups Q and R.

Distribution

While basal K2b* has not yet been identified, populations with living members of the immediate subclades K2b1* and P* (K2b2) appear to be polarized between Oceania, South Asia and eastern Siberia.

Some Negrito populations of South-East Asia carry very high levels of K2b at the subclade level. It is carried, for instance, by more than 83% of males among the Aeta (or Agta) people of the Philippines, in the form of K2b1 (60%), P* (P-P295*, a.k.a. K2b2*) and P2.

K2b1

K2b1 is found in 83% of males of Papua New Guinea, and up to 60% in the Aeta people of the Philippines.^[4] It is also found among other Melanesian populations, as well as indigenous Australians, and at lower levels amongst Polynesians.^[4]

Major studies published in 2014 and 2015 suggest that about 27% of Aboriginal Australian males carry the subclade K2b1a1 (P60, P304, P308), which has also been referred to as "S-P308".^[4][5] (The other Y-DNA haplogroups found in indigenous Australians included two distantly-related subclades of Haplogroup K2 at low levels: basal K2* [M526] and Haplogroup M1 [M4]), as well as C1b2b [M347; previous Haplogroup C4] and basal C* [M130].

P (K2b2)

P (K2b2) is widely distributed among males of Western European, Central Asian, and Native American ancestry.

Apart from the basal paragroup P*, it has only one subclade: P1 (M45), also known as K2b2a – which is also the parent of the major haplogroups Q (K2b2a1) and R (K2b2a2).

Basal P* (K2b2*)

P* (or "pre-P") is found among 28% of males among the Aeta, as well as in Timor at 10.8%, and one case may have been found in Papua New Guinea (Kaysar et al. 2006) although this has not been verified.^[4]

P1 (K2b2a)

P1 (M45/PF5962), also known as K2b2a, is hundreds of times more common than P* (K2b2; PxM45), as it includes haplogroups Q and R, is estimated as being 14,300 years younger than K2b.^[4]

Many ethnic groups with high frequencies of P1 are located in Central Asia and Siberia: 35.4% among Tuvans, 28.3% among Altaian Kizhi,^[6] and 35% among Nivkh males.

Modern South Asian populations also feature P1 at low to moderate frequencies.^[7] In South Asia it is most frequent among the Muslims of Manipur (33%), but this may be due to a very small sample size (nine individuals). Cases of P1 (M45) reported in South Asia may be unresolved cases or R2 or Q.^[7]

§ These may include members of haplogroup R2.

See also

• Ancient populations haplogroups are assumed from small ancient sample sizes.
  • † Stands for assumed extinction (no living sample of the same haplogroup)
    • ^[8] Entire Phlogeny except for Hg X + distribution of K2b1 clades K2* clades and K2c+K2d, as well as P(xm45)
      • ^{[9][10][11][12]} Ancient dna.
        • ^[13][14]

^{[15] [16] [17] [18] [19] [20] [21] [22][23][24][25]} Modern Populations+Ancient Basques

• ^[2][26] y-dna haplogroup X.

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References

Notes

[Assuming B70 ky for the TMRCA of M168 chromosomes,10 we estimate the interval of time between the diversification of K-M9 and that of K-P331 to be <3 ky. This rapid diversification has also been assessed using whole Y-chromosome sequence data.22 In addition, we estimate the total time between the common ancestor of K-M9 and that of P-P295 to be <5 ky, and the time between the common ancestor P-P295 and that of P-P27 to be 12.3 ky (95% CI: 6.6–20 ky).http://www.nature.com/ejhg/journal/vaop/ncurrent/full/ejhg2014106a.html]