I'm reading fabulous Cavalli-Sforza's book "Genes,
Peoples and Languages". Very pleasant and clearing book. IE tribes are
described as nomadic shepherds, protect by small groups of warriors.
This clears a pattern of nomadic shepherds becoming satellites of great urban
nuclei, progessively forming mercenarian gangs, and further originaring
militar gouvernments and dinasties, like Germans in Western Romania, Mongols in
China or Turks in Arabian-Muslim Near East.
Thus, from initial PIE nucleus in Ukrainian
steppes, we can see:
1- groups being "Hurritized" and further
"Sumerianized" (Hittites and Mitanians)
2- groups being "Minoanized" (Greeks - Ionians and
Acheans)
3- an expansion of Asian nomads, originating the
Indo-Iranian stock, reaching Europe - Scythes - and spreading the Satemic
shift.
4- groups being mixed with Gimbutas'
"proto-european" farmers (Balto-Slavic, Germans, Celts, Italiotes, most of the
European IE)
5- Indo-Aryans being "Dravidianized"
(Mohenjo-Daro's cities) (Indians)
6- Italiotes being "etrusquized" (Romans-Latins)
7 - Tokharians in China (also nomads?)
Joao SL