The immediate descendants of IJ are
Haplogroup I and
Haplogroup J. Its sole sibling is
K (which includes most of the world's male population).
Haplogroup IJ derived populations account for a significant proportion of the pre-modern populations of
Europe (especially Scandinavia and the Balkans),
Anatolia, the
Caucasus, the
Middle East (especially Arabia, Levant and Mesopotamia) and coastal
North Africa. As a result of mass migrations during the modern era, they are now also significant in
The Americas and
Australasia.
Haplogroup I appears to have arisen in Europe, so far being found in Palaeolithic sites throughout Europe (Fu 2016), but not outside it. It diverged from common ancestor IJ* about 43,000 years B.P. (Karafet 2008). Early evidence for haplogroup J has been found in the Caucasus and Iran (Jones 2015, Fu 2016). In addition, living examples of the precursor Haplogroup IJ* have been found only in ethnicities living in modern day Iran. This may indicate that IJ originated in
West Asia.
Origin
A 2008 estimate suggested that the
most recent common ancestor of haplogroup IJ could have lived 30,500–46,200 years ago,[3] while another estimate suggests 43,000–45,700 years.[1]
Examples of the basal/paragroup Haplogroup IJ* (M429) were first reported in a 2012 study of genetic diversity in
Iran, by Grugni et al. These individuals were reported to be positive for M429 and negative for the
SNPs M170 and M304, which define
haplogroup I and
haplogroup J respectively. However, because the researchers filtered for relatively few SNPs, these individuals may have carried less well-known SNPs equivalent to M170 and M304.[4][5] Given the limited scope of the testing – and the small number of haplogroup IJ samples that were discovered – few firm conclusions have yet been drawn.
IJ split in a typically disjunctive, almost mutually-exclusive geographical pattern, with J-M304 far more common in the Caucasus, and I-M170 far more common in Europe; the age of IJ and its subclades suggest that IJ probably entered Europe through the
Balkans, some time before the
last glacial maximum (about 26,500 years BP). The same geographic corridor (the Balkans) also supported later gene flows, including the
Early Neolithic Farmers from Anatolia about 9,000 years BP.
Phylogeny and distribution
IJ (M429, P123, P124, P125, P126, P127, P129, P130, S2, S22, per ISOGG 2008)
I (M170, P19, M258, P38, P212, U179, Haplogroup I notation updated to ISOGG 2008; L41, M170, M258, P19_1, P19_2, P19_3, P19_4, P19_5, P38, P212, U179)
I* (unobserved)
I1 (M253, M307, M450/S109, P30, P40, S62, S63, S64, S65, S66, S107, S108, S110, S111, per ISOGG 2008; also L64, L75, L80, L81, L118, L121/S62, L123, L124/S64, L125/S65, L157.1, L186, L187, L840, M307.2/P203.2) Typical of populations of
Scandinavia and
Northwest Europe, with a moderate distribution throughout
Eastern Europe
I1* (unobserved)
I-CTS12768 (no phylogenetic name as of 2021)
I-CTS12768* – living example in Sweden.
I-Z17954 (no phylogenetic name as of 2021)
I-Z17954* (unobserved)
I-Y21293 – living example in Netherlands.
I-Y19092 – living examples in Normandy and Finland.
I1a – DF29/S438
I1a* - living examples in Sweden, Denmark and Portugal.
I2a (P37.2) (formerly I1b1) Typical of the
South Slavic peoples of the
Balkans, especially the populations of
Bosnia,
Croatia,
Serbia and
Slovenia ; also found with high haplotype diversity values, but lower overall frequency, among the West Slavic populations of
Slovakia and the
Czech Republic; a node of elevated frequency in
Moldavia correlates with that observed for Haplogroup I2a (but not for Haplogroup I1)
I2a*
I2a1 (M423)
I2a1*
I2a1a (P41.2/M359.2) (formerly I1b1a)
I2a2 (M26) (formerly I1b1b) Typical of the population of the so-called "archaic zone" of
Sardinia; also found at low frequencies among populations of Southwest Europe, particularly in
Castile,
Béarn, and the
Basque Country
I2b1 (M223, P219/S24, P220/S119, P221/S120, P222/U250/S118, P223/S117) (formerly I1b2a - old I1c) Occurs at a moderate frequency among populations of Northwest Europe, with a peak frequency in the region of
Lower Saxony in central
Germany; minor offshoots appear in
Moldavia and
Russia (especially around
Vladimir,
Ryazan,
Nizhny Novgorod, and the
Republic of Mordovia), and among speakers of
Persian (including Iranians,
Hazaras in Afghanistan and Pakistan, and
Tajiks in Afghanistan)
I2b1*
I2b1a (M284) (formerly I1b2a1) Generally limited to a low frequency in
Great Britain
^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.
^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 S, as of 2017, is also known as K2b1a. (Previously the name Haplogroup S was assigned to K2b1a4.)
^ Haplogroup M, as of 2017, is also known as K2b1b. (Previously the name Haplogroup M was assigned to K2b1d.)