When you mash historical linguistics hard enough into paleogenetics, interesting things fall out:
The steppe extends roughly from the Dniepr to the Ural or 30° to 55° east longitude, and from the Black Sea and the Caucasus in the south to the temperate forest and taiga in the north, or 45° to 55° north latitude.
Via Wikipedia
What we can now say pretty much for sure: Proto-Indo-European was first spoken on the Pontic Steppes around 4000 BCE. That’s the grasslands north of the Black Sea and west of the Urals; today, it’s the Ukraine and parts of European Russia. The original PIE speakers (which we can now confidently identify with what archaeologists call the Yamnaya culture) were the first humans to domesticate horses.
And – well, basically, they were the first and most successful horse barbarians. They invaded Europe via the Danube Valley and contributed about half the genetic ancestry of modern Europeans – a bit more in the north, where they almost wiped out the indigenes; a bit less in the south where they mixed more with a population of farmers who had previously migrated in on foot from somewhere in Anatolia.
The broad outline isn’t a new idea. 400 years ago the very first speculations about a possible IE root language fingered the Scythians, Pontic-Steppe descendants in historical times of the original PIE speakers – with a similar horse-barbarian lifestyle. It was actually a remarkably good guess, considering. The first version of the “modern” steppe-origin hypothesis – warlike bronze-age PIE speakers domesticate the horse and overrun Europe at sword- and spear-point – goes back to 1926.
But since then various flavors of nationalist and nutty racial theorist have tried to relocate the PIE urheimat all over the map – usually in the nut’s home country. The Nazis wanted to believe it was somewhere in their Greater Germany, of course. There’s still a crew of fringe scientists trying to pin it to northern India, but the paleogenetic evidence craps all over that theory (as Cochran explains rather gleefully – he does enjoy calling bullshit on bullshit).
Then there have been the non-nutty proposals. There was a scientist named Colin Renfrew who for many years (quite respectably) pushed the theory that IE speakers walked into Europe from Anatolia along with farming technology, instead of riding in off the steppes brandishing weapons like some tribe in a Robert E. Howard novel.
Alas, Renfrew was wrong. It now looks like there was such a migration, but those people spoke a non-IE language (most likely something archaically Semitic) and got overrun by the PIE speakers riding in a few thousand years later. Cochran calls these people “EEF” (Eastern European Farmers) and they’re most of the non-IE half of modern European ancestry. Basque is the only living language that survives from EEF times; Otzi the Iceman was EEF, and you can still find people with genes a lot like his in the remotest hills of Sardinia.
Even David Anthony, good as he is about much else, seems rather embarrassed and denialist about the fire-and-sword stuff. Late in his book he spins a lot of hopeful guff about IE speakers expanding up the Danube peacefully by recruiting the locals into their culture.
Um, nope. The genetic evidence is merciless (though, to be fair, Anthony can’t have known this). There’s a particular pattern of Y-chromosome and mitochondrial DNA variation that you only get in descendant population C when it’s a mix produced because aggressor population A killed most or all of population B’s men and took their women. Modern Europeans (C) have that pattern, the maternal line stuff (B) is EEF, and the paternal-line stuff (A) is straight outta steppe-land; the Yamnaya invaders were not gentle.
How un-gentle were they? Well…this paragraph is me filling in from some sources that aren’t Anthony or Cochran, now. While Europeans still have EEF genes, almost nothing of EEF culture survived in later Europe beyond the plants they domesticated, the names of some rivers, and (possibly) a murky substratum in some European mythologies.
The PIE speakers themselves seem to have formed, genetically, when an earlier population called the Ancient Northern Eurasians did a fire-and-sword number (on foot, that time) on a group of early farmers from the Fertile Crescent. Cochrane sometimes calls the ANEs “Hyperboreans” or “Cimmerians”, which is pretty funny if you’ve read your Howard.
