Human Y chromosome DNA grouping indicating common ancestry
This article is about the Y-chromosome haplogroup K2. For mitochondrial DNA haplogroup K2, see
Haplogroup K (mtDNA). For the Y-DNA haplogroup known until 2008 as K2, see
Haplogroup T (Y-DNA). For the haplogroup sometimes known as "K-P256", see
Haplogroup M-P256.
Haplogroup K2, also known as K-M526 and formerly known as K(xLT) and MNOPS,[4] is a human
Y-DNA haplogroup.
Relative to its age, the
internal structure of K2 is extremely complex, and subclades of it are carried by males native to regions including
Australasia,
Oceania,
Southeast Asia,
South Asia,
East Asia,
Central Asia, the
Americas,
Europe, and the
Horn of Africa. Many of its branches are very common, the most numerically important being
R in Europe and South Asia and
O in East and Southeast Asia (as well as recent immigrants to other continents).
Haplogroups N and
Q, while they are less common overall, are also very widespread, in northern Eurasia and the Americas respectively.
M and
S are almost entirely restricted to
Oceania and eastern
Indonesia, where they occur at high frequency.
Basal paragroup K2* has been identified among native Australians, about 27% of them carry basal K-M526∗.[5]
K2a* has been found only in
Upper Paleolithic remains from western
Siberia and the
Balkans, known respectively as "
Ust'-Ishim man" and "
Oase-1".[6] The only primary branch of K2a, known as K-M2313*, has been documented in two living individuals, who have ethnic ties to
South Asia and
South East Asia respectively: a
Telugu from India and an
ethnic Malay from Singapore. In addition, K-Y28299, which appears to be a primary branch of K-M2313, has been found in three living individuals from
India.[7] Another subclade, NO (M214)* – which for a time was thought to be synonymous with K2a (M2308)* – has not been identified in living individuals or remains.
Basal paragroup K2b* has not been identified among living males but was found in Upper Paleolithic
Tianyuan man from China.[8]K2b1 (P397/P399) known previously as Haplogroup MS, and
Haplogroup P (P-P295), also known as K2b2 are the only primary clades of K2b.
According to geneticist
Spencer Wells, haplogroup K, from which haplogroup P descend, originated in the
Middle East or
Central Asia. It is likely that haplogroup P diverged somewhere in South Asia into P1, which expanded into Siberia and Northern Eurasia, and into P2, which expanded into Oceania and Southeast Asia.[9]
Population geneticist Tatiana Karafet and other researchers (2014) point out that both K2b1 and P* are virtually restricted geographically to
South East Asia and
Oceania.[2] Whereas, in a striking contrast,
P1 (P-M45) and its primary subclades
Q and
R now make up "the most frequent haplogroup in
Europe, the
Americas, and
Central Asia and
South Asia". 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.[2] However, these authors also stipulated that haplogroup K might have arisen in Eurasia and later went extinct there, and that either origin hypothesis is "equally parsimonious".[10]
At the level of highly derived subclades, K2 is almost universal in some modern Eurasian, Australasian and Native American populations. Haplogroup
NO (M214), as a descendant of
K2a (M2308), includes most males among
Southeast Asian,
East Asian, and
Finno-Ugric-speaking populations.[6] Similarly, the direct descendants of
K2b include the major haplogroups
M;
S,
P,
Q, and
R. These are now numerically in dominant in:
Oceania,
Central Asia,
Siberia, among
Native American populations,
Europe, and
South Asia.
A rapid diversification within and from K2 (M526), most likely in Southeast Asia, is suggested by estimates of the point in time that K2 branched off from K* (M9). Likewise the branching from K2 of K2b (P331) and
Haplogroup P (K2b2 P295) from K2b, as well as Haplogroups Q and R from P (K2b2), and their subsequent expansions westward in Europe,[2] and eastward into the Americas.
K2c, K2d, and K2e are extremely rare subhaplogroups that are found in specific parts of South and Southeast Asia.[2] K2c (P261) has been reported only among males in
Bali and K2d (P402) only in
Java. K2e (M147), which has been found in two modern cases from
South India,[2] was provisionally named "pre-NO" (among other names), as it was believed initially to be ancestral to K2a (NO). However, it was later found to be a primary branch of Haplogroup K2 (K-M526) and a sibling of K2a; the new clade was renamed K2e.
Studies published in 2014 and 2015 found that up to 27% of
Aboriginal Australian males carry K-M526*, which could not be classified into a known subclade at the time, and another 27% probably have
K2b1a1 (P60, P304, P308; also known as "S-P308") and perhaps 2.0% have
Haplogroup M1 – also known as M-M4 (or "M-M186") and K2b1d1.[12][2]
Naming
The name K2 was introduced in 2014, following dissatisfaction with the previous names.
K(xLT), the name introduced by the
Y Chromosome Consortium in 2012 to replace MNOPS, was controversial. Under the previous methodology, a term such as "K(xLT)" designated all clades and subclades that belonged to K, but did not belong to
Haplogroup LT; the haplogroups subordinate to MNOPS would likely have been renamed "U", "V", "W" and "X", and MNOPS would therefore have become "MNOPSUVWX". This posed a problem, because there was no way to disambiguate between "K(xLT)" in the broad and narrow meanings of the term.
Footnotes
^Fu, Qiaomei; Li, Heng; Moorjani, Priya; Jay, Flora; Slepchenko, Sergey M.; Bondarev, Aleksei A.; Johnson, Philip L. F.; Aximu-Petri, Ayinuer; Prüfer, Kay; de Filippo, Cesare; Meyer, Matthias; Zwyns, Nicolas; Salazar-García, Domingo C.; Kuzmin, Yaroslav V.; Keates, Susan G.; Kosintsev, Pavel A.; Razhev, Dmitry I.; Richards, Michael P.; Peristov, Nikolai V.; Lachmann, Michael; Douka, Katerina; Higham, Thomas F. G.; Slatkin, Montgomery; Hublin, Jean-Jacques; Reich, David; Kelso, Janet; Viola, T. Bence; Pääbo, Svante (October 2014).
"Genome sequence of a 45,000-year-old modern human from western Siberia". Nature. 514 (7523): 445–449.
Bibcode:
2014Natur.514..445F.
doi:
10.1038/nature13810.
PMC4753769.
PMID25341783.
^Karafet et al. 2015"This pattern leads us to hypothesize a southeastern Asian origin for P-P295 and a later expansion of the ancestor of subhaplogroups R and Q into mainland Asia. An alternative explanation would involve an extinction event of ancestral P-P295* chromosomes everywhere in Asia. These scenarios are equally parsimonious. They involve either a migration event (P* chromosomes from Indonesia to mainland Asia) or an extinction event of P-P295* paragroup in Eurasia."
^Van Oven M, Van Geystelen A, Kayser M, Decorte R, Larmuseau HD (2014). "Seeing the wood for the trees: a minimal reference phylogeny for the human Y chromosome". Human Mutation. 35 (2): 187–91.
doi:
10.1002/humu.22468.
PMID24166809.
S2CID23291764.
^ Haplogroup K2b (M1221/P331/PF5911) is also known as Haplogroup MPS.
^ Haplogroup K2e (K-M147) was previously known as "Haplogroup X" and "K2a" (but is a sibling subclade of the present K2a).
^K-M2313*, which as yet has no phylogenetic name, has been documented in two living individuals, who have ethnic ties to India and South East Asia. In addition, K-Y28299, which appears to be a primary branch of K-M2313, has been found in three living individuals from India. See: Poznik op. cit.;
YFull YTree v5.08, 2017, "K-M2335", and;
PhyloTree, 2017, "Details of the Y-SNP markers included in the minimal Y tree" (Access date of these pages: 9 December 2017)
^ Haplogroup K2b1 (P397/P399) is also known as Haplogroup MS, but has a broader and more complex internal structure.