Like three peas in a pod

One of the most interesting questions still waiting to be answered by ancient DNA is where exactly did the ancestors of the present-day European and South Asian bearers of Y-haplogroup R1a part their ways? Indeed, the answer to this question is likely to be informative about the place and time of the split between the Balto-Slavic and Indo-Iranian language families.

I was doing some reading today and discovered that the peoples associated with the Bronze Age Fatyanovo-Balanovo and Unetice archeological cultures shared strikingly similar metalwork, despite being separated by well over two thousand kilometers of forest and steppe. Apparently, this similarity is especially pronounced in the metalwork of the Unetice culture from what is now Slovakia (see Ancient Metallurgy in the USSR: The Early Metal Age, page 136).

S11953 is currently the only sample from Slovakia associated with the Unetice culture (Sirak et al. 2020). There are no Fatyanovo-Balanovo samples available yet. However, as far as I can tell, I0432 from Samara, Russia, should be a decent stand in (Mathieson et al. 2015).

Of course, both S11953 and I0432 belong to Y-haplogroup R1a. Moreover, S11953 belongs to a typically Balto-Slavic subclade of R1a, while I0432 belongs to a closely related subclade that is dominant nowadays among the Indo-Iranian speakers of Asia.

S11953 is younger than I0432, but this doesn't necessarily mean that his ancestors arrived in East Central Europe from deep in Russia during the Bronze Age. Indeed, the opposite is more likely to be true. That is, I0432 is probably the recent decedent of migrants from somewhere near the North Carpathians, because he shows elevated European Neolithic farmer ancestry compared to earlier ancients from the Samara region (see here).

Below is a Principal Component Analysis (PCA) showing how S11953 and I0432 compare to each other in the context of ancient West Eurasian genetic variation. Obviously, they're sitting in the same part of the plot, which suggests that they harbor very similar ratios of ancient genetic components and probably share relatively recent ancestry. The relevant PCA datasheet is available here.

I've also highlighted myself, Davidski, on the plot. That's because I share the same Balto-Slavic-specific subclade of R1a with S11953 and, in terms of overall ancestry, I'm similar to both S11953 and I0432. Moreover, I'm the speaker of Polish, which is a Balto-Slavic language. What are the chances that we're dealing here with a remarkable string of coincidences? Indeed, was the North Carpathian region perhaps the homeland of the language ancestral to both Balto-Slavic and Indo-Iranian?

However, please note that there's nothing unusual or remarkable about my ancestry. The vast majority of people of Central, Eastern and Northern European origin - that is, mostly the speakers of Balto-Slavic, Germanic and Celtic languages - would also land in this part of the plot.

See also...

On the doorstep of India

Y-haplogroup R1a and mental health

The mystery of the Sintashta people