Most answers assume that R1b and IE are the same. The assumption probably stems from the unthinkable, horrifying alternative that R1b folks could have adopted the IE language from the inferior, R1a Slavic people. R1b and IE⁸ are of course not the same. It predates IE by millennia. It is found in Tarim basin (the ancient mummies did not speak Tocharian. Tocharians were R1a), Africa, and in Europe itself as early as 14000 years ago. The fact that the highest concentration of R1b is to be found in Aquitaine, Navarra and the northern Spanish coast speaks volumes. It is absolutely illogical to speak of dna replacement by violence or otherwise when the more “Indo-European” regions in fact have lower concentrations of R1b but higher levels of R1a. The data speaks for itself. The concentration of R1b coincides with the expansion of the Bell Beaker culture. These R1b people spoke Vasconic, Etruscan and other ancient languages. These R1b folks would have come, not from the Steppe, but from the Caucasus and Anatolia, via the Balkans and the sea, as neolithic farmers. They displaced earlier hunter-gathers. The innovations of the Bell Beaker enabled them to expand to all of Western Europe. But their expansion pitted them against the R1a IE folks pushing westwards as evidenced by the Corded Ware and other IE groups