So here we have an aDNA paper from Narasimhan et al , published at bioRxiv today. It is a big paper, containing more than 350 ancient samples, from important ancient sites of Central Asia ,Iran and also S Asia. The apparent impression from the first read is that, they have found ''evidence'' of migration from Steppe to S Asia. They don't have Mature Harappan samples, which is a shame.The S Asian samples are from Swat/Pakistan dating from only around 1200 bce to historical period. In those samples they have found no R1a except a singleton R1a from Saidu_Sharif_IA I6891 (500-300 BCE) .The archaeological studies from the past have shown that Swat culture had largely female centered characteristics rather than the expected opposite , see here for example.The importance of feminine is also reflected in modern culture of Kalash also, like freedom of women, and goddess cult, see here.Interestingly, they have ruled out BMAC as potential source population of S Asians, this goes against the traditional AIT model . I am suspecting for example, the West Siberian HG ancestry they have discovered is actually Central Asian HG component ,which included N India.In the BMAC main cluster they measure this ancestry at 13%, but in Sarazm EN , it had around 25% presence(just as in the samples from Pakistan!, suggesting dilution by West Asian migration rather than what they imply.) , in their qpAdm based analysis(p.22 main paper) we only see the green Siberian HG ancestry appearing in ancient S Asians, while EHG related one is absent. From main paper p.9:
Third, between 3100-2200 BCE we observe an outlier at the BMAC site of Gonur, as well as two outliers from the eastern Iranian site of Shahr-i-Sokhta, all with an ancestry profile similar to 41 ancient individuals from northern Pakistan who lived approximately a millennium later in the isolated Swat region of the northern Indus Valley (1200-800 BCE). These individuals had between 14-42% of their ancestry related to the AASI and the rest related to early Iranian agriculturalists and West_Siberian_HG.There cannot be any doubt that this West_Siberian_HG-related ancestry was in N India since at least 3000 BCE, but probably much earlier. Also finding ancestry related to ''S Asian HG''s may imply, that it was also well present in N India prior to 2000 bce , but was it uniformly present? only aDNA from India will clarify.Their argument is mainly based on the samples like Gonur2_BA migrant being representative of the whole SSVC population!. But in near future, if we get samples from SSVC proper and they show strong relation to the SPGT samples, the whole argument falls.They also didn't find the S Asia specific R1a-L657, in any of their ancient samples ...
The Genomic Formation of South and Central AsiaVagheesh M Narasimhan et al.
The genetic formation of Central and South Asian populations has been unclear because of an absence of ancient DNA. To address this gap, we generated genome-wide data from 362 ancient individuals, including the first from eastern Iran, Turan (Uzbekistan, Turkmenistan, and Tajikistan), Bronze Age Kazakhstan, and South Asia. Our data reveal a complex set of genetic sources that ultimately combined to form the ancestry of South Asians today. We document a southward spread of genetic ancestry from the Eurasian Steppe, correlating with the archaeologically known expansion of pastoralist sites from the Steppe to Turan in the Middle Bronze Age (2300-1500 BCE). These Steppe communities mixed genetically with peoples of the Bactria Margiana Archaeological Complex (BMAC) whom they encountered in Turan (primarily descendants of earlier agriculturalists of Iran), but there is no evidence that the main BMAC population contributed genetically to later South Asians. Instead, Steppe communities integrated farther south throughout the 2nd millennium BCE, and we show that they mixed with a more southern population that we document at multiple sites as outlier individuals exhibiting a distinctive mixture of ancestry related to Iranian agriculturalists and South Asian hunter-gathers. We call this group Indus Periphery because they were found at sites in cultural contact with the Indus Valley Civilization (IVC) and along its northern fringe, and also because they were genetically similar to post-IVC groups in the Swat Valley of Pakistan. By co-analyzing ancient DNA and genomic data from diverse present-day South Asians, we show that Indus Periphery-related people are the single most important source of ancestry in South Asia — consistent with the idea that the Indus Periphery individuals are providing us with the first direct look at the ancestry of peoples of the IVC — and we develop a model for the formation of present-day South Asians in terms of the temporally and geographically proximate sources of Indus Periphery-related, Steppe, and local South Asian hunter-gatherer-related ancestry. Our results show how ancestry from the Steppe genetically linked Europe and South Asia in the Bronze Age, and identifies the populations that almost certainly were responsible for spreading Indo-European languages across much of Eurasia.