Origin and Diffusion
Languages diffuse from their place of origin through migration
Dialects within languages also emerge through migration and isolation
A language originates at a particular place and traditionally diffuses to other locations through the migration of it's speakers. The location of English-language speakers serves as a case study fro understanding the process by which languages have been distributed around the world.
Origin and Diffusion of Indo-European: "War" Hypothesis
The early origin and early diffusion of language families predate recorded history. Linguists and anthropologists disagree on when and where Indo-European originated and the process and routes by which it diffused.
How languages evolve - Alex Gendler
Animated map shows how Indo-European languages may have evolved