If I'm not mistaken the last Lazaridis paper found out that Proto Indo-Europeans are a mixture of bronze age Iranians and European hunter
gatherers, I think that proves that the homeland of the Proto Indo-European langauge should be in Iran as this will accounts for the
mutual Indo-European, Semitic, Kartvelian and North-East Caucasian lexical borrowings, whereas if the homeland of PIE was to be the
Ukraine we should have had mutual lexical borrowings between PIE and Basque (wich is related to the pre Indo-European languages spoken
during neolithic Europe)
As a matter of fact, there are similar words for numerals, tools and plants between PIE, Proto Kartvelian, Proto Semitic and Proto East-
Caucasian.
All this fits very well with the West Asian origin (probably even Iranian) of R1b-M269 that was found in the earliest Indo-European
cultural sites (Yamnaya...)
The most solidly argued theories about the cradle of the Indo-European (IE) proto-language are 1) the Pontic and 2) the Anatolian. The
first proposed the steppes north of the Black Sea, in what are today south-Ukraine and south-Russia; the second: some region in central or
eastern Anatolia. Both theories allow for contacts with the Caucasus and the indigenous Caucasian languages: north for the first, south
for the second.
As we will see, the Pontic theory is enfeebled by the total absence of any contact between IE and the North-West Caucasian languages
(NWC): Cherkess-Kabard-Abkhaz, which should have been their most immediate neighbours. NWC languages like Cherkess, that in historical
times have occupied the Black Sea coast between Crimea and the Caucasus range, diverge from IE in all respects: typologically, lexically,
phonologically.
The Anatolian theory, on the other hand, explains the profound affinities (typologically, lexically, phonologically) with proto-Semitic,
proto-Kartvelian (South-Caucasian: SC) and proto-Nakh-Daghestani (the North-East Caucasian languages: NEC).
...
The numerals
Kartvelian and IE languages borrowed in prehistorical times a series of numerals from proto-Semitic, especially the numerals 6 and 7. We
thus have shesh and sheva in Hebrew, sitta and sab’a in Arabic, shetta and shub’a in Aramaic, etc.
In the Indo-European family, there is a close parallel: sex and septem in Latin, sechs and sieben in German, sześć and siedem in Polish,
sheshí and septyni in Lithuanian.
And in Kartvelian, 6 is ekvsi in Georgian, usgwa in Svan; 7 is švidi in Georgian, išgwid in Svan.
What is interesting and revealing is that there happened a chassé-croisé of designations of numerals. Thus, in Georgian the Semitic 4
(arb’a in Hebrew) became 8 (rva), while the Georgian 4 (oti) is identical with the IE 8: octo, ahtau, etc…
Moreover, 8 in Indo-European was a dual, something which is visible in Sanskrit, Avestan and Gothic: ahtau. A dual means that 8 designated
“twice 4”, which sends us immediately to the Georgian oti = 4. Oti, if we reconstruct it as *okt– (-i is simply the termination of the
nominative in Georgian), explains why the IE octo, ahtau is a dual. The same mechanism would explain why the Semitic 4 (arb’a in Hebrew)
became 8 (rva) in Kartvelian (Georgian).
...
It is thus perfectly coherent that the Georgian oti = 4, while the IE 8 octo (ahtau etc.) is a dual, that is: 4 x 2 . In the same way, the
Semitic 4 (arb’a in Hebrew) became the Georgian 8 = rva. This also vindicates Gamkrelidze’s theory that the formal identity, in IE
languages, of the numeral 9 with the adjective “new” is not due to mere coincidence: novum-novem, neu-neun, new-nine etc. 9 was simply
opening a new series.
All this indicates that Indo-European must have been formed in the vicinity of Semitic and Kartvelian and possibly other Caucasian
languages. This excludes the possibility of a cradle north of the Black Sea, and totally excludes the Danube area, the Balkans, or any
part of Eastern Europe. Those regions are too far from the Caucasus and from the Semitic languages, and we have seen that in the Neolithic
in today’s Europe the languages might have had a typology similar with today’s Basque, or with the Finnic languages, which have an
agglutinative typology.
It is only the Anatolian hypothesis that explains the borrowings and the many lexical common terms between IE, Kartvelian and Semitic. The
borrowings from Semitic into IE and Kartvelian are too numerous to be listed here. Between IE and Kartvelian we have surprising
correspondences, such as the verbal root *sed– to sit, to stay, to remain (identical in IE and Kartvelian), ordinal numerals such as the
Georgian pirveli (first), which cannot come from a Slavic language, with which Georgian had no contact by the time of the first written
texts in the Vth century.
Numerous are also the lexical archaic correspondences between IE and the North-East Caucasian languages (Chechen, Avar etc.), while Indo-
European borrowings into Basque or Finnic are all recent and can be easily traced historically.
All this shows that proto-Indo-European was formed in Eastern Anatolia, in the vicinity of the Semites and Caucasians.