We can not say that this areas are not civilized or to call them backwards. We may call them different. We can take for example the uses of animals in order to expand the commerce of their area. If we research about the use of camels, for example, we could see that it gained an special place within those who wanted to travel through many difficult areas like deserts. So in the case of camels they were not backwards, they used a different method to obtain success
History was a driving force behind such migration, since humans tended to move to new territory when they lacked food, shelter, or other resources--meaning that most of the conflicts throughout history have been driven by the same forces that drove migration out of Africa.
Do you mean what caused it? or what the after affects where?