Archaeology and common Y DNA in modern Indo European speakers which age estimates show migrations starting in certain areas 7,000-5,000ybp. Show that Indo European languages most likely started, or took off and spread from these areas.
Traditionally in the Kurgan theoryproto Indo European languages began around Bug Dniester culture in Ukraine about 7,000ybp and in Yamna culture in Russia and Dnieper Donets Ukraine starting about 5,600ybp. Since there are 6,000 year old Kurgans in both southeast Poland and Caucus that kind of extends were very early Indo Europeans were to the Caucus and north mid east and deeper in Europe.
So far we know that R1a1a1 M417 is for sure a proto Indo European marker and is from the Dnieper Donets and Yamna Ukraine Russia area. It spread with Balto Slavic languages out of Yamna culture forming into Corded ware around 5,000ybp and R1a1a1b1 Z283. Indo Iranian migrating out of Yamna culture forming into Sinshat and Abashevo and Y DNa R1a1a1b2 Z93.
Also Y DNA from supposedly proto Balto Slavic culture Corded ware two from 4,800ybp in Poland were G and I or J and two from 4,600ybp in central Germany were at least R1a1a M17. Seven Y DNA samples from 4,000 year old Tarim mummies in west China who were suspected to be connected with early Indo Iranian speakers all were at least R1a1a M17. Four 3,800-3,400 year old Y DNA samples from supposedly early Indo Iranian Andronovo culture in central Siberia three had at least R1a1a M17 and one had C probably from Mongoloid Siberians.
So Y DNA from cultures the Kurgan theory say were early Indo Iranian or early Balto Slavic speakers all back up the idea that R1a1a1 M417 is a early early Indo European Y DNA haplogroup from the Ukraine-Russia Bug Dniester-Yamna cultures. There is also a western European branch most likely from Germanic Italo Celts R1a1a1a L664. The proto Germanic Italo Celts were dominated by R1b1a2a L23 then R1b1a2a1 L51 but they probably picked up some R1a1a1 M417 since they were so close to other Indo Europeans in Russia Ukraine area 5,000-6,000ybp. So it seems they then formed their own branch. So the common ancestor of all those Indo European R1a branches is R1a1a1 M417.
Here is a migration map of Indo European R1a1a1 M417 made by Eupedia.
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