Distant cousins

One of the things that fascinates me about Indo-European studies is discovering the antics, mishaps and shenanigans of my very early ancestors and their relatives—in many cases, people who aren't in my direct line of ancestry, but who were closely related to people who were.  For instance, last time I talked about this, I made a direct line between the Single Grave culture (which was a western Dutch/Danish/North German variation of the Corded Ware horizon) and the Celtic expansion later out of La Tene and Hallstatt.  The Corded Ware is really the first expansion into northern Europe from the steppes, and it is largely responsible, most likely, for the later development of all of the Indo-European cultures of Europe with the exception of some of the paleo-Balkan ones and their descendants (like the Greeks) which came more directly from Yamnaya or post-Yamnaya cultures (like Catacomb.)  Not only the Celtics from Single Grave variation of Corded Ware, but Germanics from the Battle-Axe variation of Corded Ware would make up the vast majority of my late Neolithic to EMBA ancestry.

But on the far eastern edge of the Corded Ware horizon, the Russian forest steppe north of the Catacomb culture at the southern end of the Urals and around the Samara Bend, we have the Abashievo and Fatyanovo variations, which in turn led to the Sintashta, which is generally considered the earliest definitely Indo-Iranian culture.  If you look at the PCA, you'll see that the Sintashta culture was absolutely congruent with the Corded Ware genetically, so although separated by many miles, these were the same people as my own ancestors further west, and even seem to have the same degree (more or less) of hunter-gatherer DNA, at least at this point in time.  (I don't know what this means with regards to the Poltavka culture, which is believed to be a descendant of Yamnaya specifically.  I'd like to see if they cluster closer to Yamnaya or Corded Ware, and how much they really contributed to Sintashta, if at all.) There were some contacts we know of (both from linguistics and from the odd DNA outlier) between some Siberian peoples who likely spoke very early Uralic or Yeniseian languages.

From Sintashta came the Andronovo horizon which led to the Scythians, for example.  Which is why it is not surprising to understand that the Greeks described the Scythians that their Black Sea colonists met during the Classic Age met as having a uniformly European physical type, and who lived in a way that wouldn't have seemed too unfamiliar to early Celts for that matter (although the choice of environment; open steppelands vs forested north European plain certainly contributed to some local developments of the culture.)  Although they lost their language eventually, the descendants of these Iranian-speaking steppe raiders of eastern Europe and central Asia, with some admixture from the Slavs, eventually became the Cossacks, it's believed, and still maintained a great deal of their original culture even so. (Of course, the Slavs were ultimately also descended from a Corded Ware variant culture, so they were distant cousins with similar genetics already anyway.  Admixture from waves of Hunnic, Mongol and Turkic invaders probably introduced more noticeable admixture anyway, although in surprisingly low volumes.)

This spread of specifically European genetics far and wide across Central Asia, specifically by the Andronovo wave that grew out of Sintashta, has led to European genetics turning up in some places where you wouldn't necessarily expect it.  The Uighurs, while speaking a Turkic language and practicing a Mahometan faith, are quite European in genetics and physical appearance, for instance, as are the Pamiris, many of whom almost look like they're just Russians dressed up in Central Asian garb.

That said, the most significant contribution genetically that they made is somewhat swamped.  The southern edge of Andronovo came across the urbanized Bactrian-Margiana Archaeological Complex (BMAC).  There was a considerable synthesis and hybridization that went on here, and the cultures that later emerged south of BMAC such as Swat, Cemetary H, Gandhara Grave, Painted Grey Ware, etc. where therefore still fairly closely related to the Corded Ware antecedents, but had picked up a lot of both cultural and genetic "detritus" which made them considerably different too.  In this new area, they further admixed (or miscegenated, if you prefer) with the locals, whom they called Dasyans (in contrast to their own label for themselves, which was Aryan) and went on to become the languages and cultures of northern India—which later spread across most of the subcontinent.

This pick-up of genetic and cultural influences that were very foreign to their earlier ancestors and the descendants of their western cousins (like myself) means that while I can recognize that the culture of India is ultimately connected in some ways to my own, it is also very alien and much more alien than the cultures of, say, Ireland or Germany or Scandinavia (which are fairly similar in many respects to my own Scottish/English ancestry), or even more distantly related peoples like the Russians or the Greeks. (To be fair, the Greeks also picked up a lot of foreign influence, but that same Greek influence backwashed across northern Europe as part of the Classical tradition adopted by the Europeans as they evolved into the modern peoples that they are today.)

So, I dunno.  Maybe it's a foolish thing to think of, but I wish I could have seen what the Indo-Aryans could have become had they had the same population replacement in India that they did in Europe.  While they clearly made a major impact on the subcontinent in terms of language, culture, and even Y-DNA, their PCAs aren't particularly close to ours, and when I see hordes of H1-B visa holding mercenary scabs all over the commons in America these days, I dislike it considerably.  Then again, were H1-Bs given to Russians or Poles or Serbians or whatever, maybe I'd dislike that somewhat too, although at least they have prettier girls, amirite?

EDIT: I found a PCA with Poltavka on it.  Poltavka clusters with Yamnaya and not with Corded Ware and Sintashta, so it can't have contributed much genetically to Sintashta after all.  Another archaeological hypothesis struck down by ancient DNA genetics!  Sintashta isn't a hybrid of Abashevo and Poltavka after all, it's simply a development of Abashevo in the same area where Poltavka used to be.  The "pulling" towards Yamnaya and Poltavka is way too modest for it to have been anything other than a very minor element of admixing.