52 ancient mitogenomes from the South Caucasus (Margaryan and Derenko et al. 2017)

Over at Current Biology at this LINK. I'm having a look now to see how this new data compare to ancient mtDNA from the Eneolithic/Bronze Age steppe.

Summary: The South Caucasus, situated between the Black and Caspian Seas, geographically links Europe with the Near East and has served as a crossroad for human migrations for many millennia [1, 2, 3, 4, 5, 6, 7]. Despite a vast archaeological record showing distinct cultural turnovers, the demographic events that shaped the human populations of this region is not known [8, 9]. To shed light on the maternal genetic history of the region, we analyzed the complete mitochondrial genomes of 52 ancient skeletons from present-day Armenia and Artsakh spanning 7,800 years and combined this dataset with 206 mitochondrial genomes of modern Armenians. We also included previously published data of seven neighboring populations (n = 482). Coalescence-based analyses suggest that the population size in this region rapidly increased after the Last Glacial Maximum ca. 18 kya. We find that the lowest genetic distance in this dataset is between modern Armenians and the ancient individuals, as also reflected in both network analyses and discriminant analysis of principal components. We used approximate Bayesian computation to test five different demographic scenarios explaining the formation of the modern Armenian gene pool. Despite well documented cultural shifts in the South Caucasus across this time period, our results strongly favor a genetic continuity model in the maternal gene pool. This has implications for interpreting prehistoric migration dynamics and cultural shifts in this part of the world.

Margaryan and Derenko et al., Eight Millennia of Matrilineal Genetic Continuity in the South Caucasus, Current Biology 27, 1–6 July 10, 2017, DOI: 10.1016/j.cub.2017.05.087

Update 30/06/2017: There are only 10 mitogenomes in this paper that are older than or contemporaneous with the Yamnaya culture of Eastern Europe (Neolithic to Early Bronze Age). But it's pretty clear that the sampled ancient groups could not have contributed maternal ancestry to the Yamnaya people, because most of their mtDNA haplogroups and/or subclades look unusual in the context of the mtDNA diversity of Eneolithic/Bronze Age steppe groups (bolded results below). For more on the controversy surrounding the "southern" ancestry in Yamnaya, see here and here.

H2+152 5900-5600 BC
H15a1 5900-5600 BC
I1 5925-5717 BC
U8b1a1 4486-4320 BC
K3 3000-2800 BC
R1a1 3000-2800 BC
J1b1b1 3000-2800 BC
K3 3039-2864 BC
H14b2 3449-3091 BC
T1 3500-3200 BC

Interestingly, what isn't mentioned in this paper is that the post-Early Bronze Age (EBA) maternal gene pool in the South Caucasus appears to have been influenced by migrations from the Pontic-Caspian steppe. Note, for instance, the presence of haplogroups U4a, U2e1e and U5a1b in the samples dated to the Middle Bronze Age (MBA), Late Bronze Age (LBA) and Early Iron Age (EIA), respectively. These markers look more at home on the steppe than in the South Caucasus.

See also...

Armenian confirmation bias

Strong mitogenomic continuity on the Armenian Plateau since the early Neolithic