Ancestor IJK | Descendants I, J | |
Possible time of origin approximately 44,400 years BP Defining mutations M429/P125, P123, P124, P126, P127, P129, P130, S2, S22 | ||
Haplogroup IJ (M429/P125) is a human Y-chromosome DNA haplogroup, an immediate descendant of Haplogroup IJK (formerly known as Haplogroup F-L15). IJK is a branch of Haplogroup HIJK.
Contents
The immediate descendants of IJ are Haplogroup I (I1: The original paternal lineage of Nordic Europe, I2: The main paternal lineage of Mesolithic Europeans) and Haplogroup J (J1: The dominant Arabic paternal lineage, J2: The Greco-Anatolian paternal lineage). 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 (esp. Scandinavia for I1 and the Dinaric Alps for I2), the Middle East (esp. Arabia/The Caucasus for J1 and The Levant/Mesopotamia for J2) and coastal North Africa. As a result of mass migrations during the modern era, they are now also significant in The Americas and Australasia.
Origin
While old estimates suggested that the most recent common ancestor of haplogroup IJ could have lived 30,500 years ago, the latest estimates suggest that he lived 42,400–46,400 years before present.
Both of the primary branches of haplogroup IJ – I-M170 and J-M304 – are found among modern populations of the Caucasus, Anatolia, and Southwest Asia. This tends to suggest that Haplogroup IJ branched from IJK in West Asia and/or the Middle East.
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. 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.
An inference may also be made that both IJ (M429) and its sole sibling, Haplogroup K (M9) diverged from the parent Haplogroup IJK closer to the Middle East than to East Asia, due to the evolutionary distance of IJK from its direct ancestor, haplogroup HIJK.
IJ split in a typical, disjunctive, almost mutually-exclusive geographical pattern, with J-M304 far more common on the Arabian Plate (hence Arabid) and I-M170 far more common in Continental Europe (hence Europid); 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) is likely to have supported subsequent gene flows, including some identified with early European farmers (from about 9,000 years BP).
Subclades
Found at low frequency in parts of Iran [1]
I L41, M170, M258, P19_1, P19_2, P19_3, P19_4, P19_5, P38, P212, U179 I* - (unobserved) I1 L64, L75, L80, L81, L118, L121/S62, L123, L124/S64, L125/S65, L157.1, L186, L187, L840, M253, M307.2/P203.2, M450/S109, P30, P40, S63, S66, S107, S108, S110, S111 I1* -