The genetic history of J2b

In Allentoft 2022 a new Caucasian hunter gatherer (CHG) sample (NEO283) was published. It was similar to two other previous ones but had the Y DNA J2b.

It's age 9700 years old is comparable to the previous oldest J2b from Zagros Neolithic in Iran. Given that the age of J2b is 15800 years we can assume that the homeland of J2b was somewhere between Caucasian range and Central Zagros of Iran. Later distribution of its subbranches support that idea.

• J2b1-M205 was found in Bronze Age Levant. Given that it appears there in relatively large number with the J1-P58 we can assume that both haplotypes expanded with early Semitic tribes in Bronze Age.  The age of main cluster (~5300 years) supports that theory. The ultimate origin of J2b1 was obviously in more northern regions. Toward the north Zagros and eastern Taurus mountains region. Grugni has found that ~6% of Tehran Armenians had J2b1. Nakhichevan Armenians also seems to have slightly higher level of this branch. It was also noticed in Khatri merchant caste in India. J2b1-B248 was found in Iron Age Armenia (Syunik, Harjis). This branch is found in modern Armenians also.
• J2b2b-Z2453 This branch was found in Mentesh-tepe in Neolithic Azerbaijan and Hajji Firuz in northwest Iran in Chalcolithic period. Lazaridis 2024 has found a J2b2b in Eneolithic Moldova. Given that this haplotype was absent in Neolithic Anatolia and Europe it is safe to assume that it moved to East Europe via the Caucasian range.  It is found in modern Armenians in small number. 
• J2b2a1-L283. This is the most puzzling subbranch of J2b. It is frequent in Balkans in Europe. But occasionally can be found in West Asia also. It was found in LBA/EIA Armenia (Norabak). Based on current data this branch moved from South Caucasus to Pontic-Caspian steppe and expanded there with Yamnaya. The age of the is 5500 years and supports its Bronze Age expansion.  In Lazaridis 2024 a J2b2a-L283 was found in Moldovan Yamnaya.  It's an IE marker that was very popular in ancient Illyrians and also in modern Albanians. It is seldom found in modern Armenia.
• J2b2a2-Z2432 It's the sister branch of L283 but has completely different distribution. It is present mostly in India. In ancient DNA it was found in BMAC and Iron Age Pakistan. Based on its age (9700 years) it must be a Neolithic/Chalcolithic lineage that moved from North Iran to East.

The first picture is the J2b2a while the second one is the J2b1. In total J2b makes ~2% of modern Armenian gene pool.

Updated: 2024 August.

See also 

• The haplogroup J2