Haplogroup L1-M22 traces Neolithic expansion in West Asia

[RCO]

Human Y chromosome haplogroup L1-M22 traces Neolithic expansion in West Asia and supports the Elamite and Dravidian connection

Pathak, A.K., Simonian, H., Aziz Ibrahim, I.A., Hrechdakian, P., Behar, D.M., Ayub, Q., Arsanov, P., Metspalu, E., Yepiskoposyan, L., Rootsi, S., Endicott, P., Villems, R., Sahakyan, H., , ISCIENCE (2024) 
doi: https://doi.org/10.1016/j.isci.2024.110016
https://www.cell.com/iscience/pdf/S2589-...1241-0.pdf

 
Highlights 
• The Y chromosome haplogroup L1-M22 originated in West Asia around 20,600 years ago.  
• A group of L1-M22 harboring population expanded with West Asian Neolithic transition.  
• Another one moved to South Asia, likely participating in Dravidian languages’ spread.  
• Their descendants expanded in South Asia around 4,000 to 3,000 years ago.  

Summary West and South Asian populations profoundly influenced Eurasian genetic and cultural diversity. We investigate the genetic history of the Y chromosome haplogroup L1-M22, which, while prevalent in these regions, lacks in-depth study. Robust Bayesian analyses of 165 high-coverage Y chromosomes favor a West Asian origin for L1-M22 ∼20.6 thousand years ago (kya). Moreover, this haplogroup parallels the genome-wide genetic ancestry of hunter-gatherers from the Iranian Plateau and the Caucasus. We characterized two L1-M22 harboring population groups during the Early Holocene. One expanded with the West Asian Neolithic transition. The other moved to South Asia ∼8-6 kya but showed no expansion. This group likely participated in the spread of Dravidian languages. These South Asian L1-M22 lineages expanded ∼4-3 kya, coinciding with the Steppe ancestry introduction. Our findings advance the current understanding of Eurasian historical dynamics, emphasizing L1-M22’s West Asian origin, associated population movements, and possible linguistic impacts.

[RCO]

One major contribution of the paper is the scientifically correct concept and definition of Caucasus/Iranian hunter-gatherers (CIHG), a big and complex population extremely important because that original population expanded to all directions, to the East in Central Asia, South Asia, Pakistan, Afghanistan and India, to the North in Eastern Europe and the steppe, to the West in Anatolia and the Mediterranean Sea, to the South in the Levant, Arabia and Northeast Africa.
Caucasus/Iranian hunter-gatherers (CIHG) was the motor of history and CIHG-related genome-wide ancestry had a big diversity of Y-DNA haplogroups. Of course L and J had different locations and J1 had a different position than J2 (J2a + J2b), even J1 basal clades had different geographic locations than J1-P58 downstream clades.