Migrations as a Black Box explanation

  How would you take a whole prehistoric household
and family group through this? (Google Earth)

My comment to European Origins: "The End of the Steppe Hypothesis? Indo-European Origins in the Caucasus - Genetics and Linguistics" (the video itself is not very well-researched, accurate or informative)

"Instead of glibly using migration as a black-box mechanism explaining genetic (and you assume linguistic) spread, what efforts are being expended to identify the reasons for and mechanisms of the boldly-drawn postulated fantasy-arrow "migrations" (with families, crops, livestock, household equipment etc) straight across major geographical features, (mountain ranges, rivers like the Volga and every one of its tributaries) and through incredibly [ecologically] diverse regions. What were the livestock en route fed for example? Would you go along te river valleys (thus having to croiss every tributary big or small) or along the watersheds (but then how would your livestock herd drink?). Would you barge through the dense forests, or go round them, and then how would you know where you are going?

If a community decides to pack up and move on to another area (why?) why would - according to your model - they all go in the same way - ending up clustered together in a new reegion which means competition for the resoourvces there? Why would not enterprising migrants head in diverse directions, well away from the lines you drew on the maps?

How did this "migration" work in real - human - terms? "