Wave model

The wave theory of language development was introduced by Johannes Schmidt (1843-1901) in linguistics. In his analysis of the phylogenetic relationships of Indo-European languages ​​he founded in 1872 the view of the gradual spatial spread of linguistic innovations, shortly called wave theory.

The wave theory was directed against the then emerging school of thought of the Ausnahmslosigkeit the sound laws with which the Neogrammarians up in the 1930s had a decisive influence in the Indo-European linguistics. In analogy to the wave theory in physics Johannes Schmidt saw developments of Indo-European languages ​​and other language families as a result of overlays. This interference and minor changes would occur in small groups and spread. In this case, the effect in the course of propagation would weaker, similar to the waves generated by a stone thrown into the water.

The wave theory supplemented by August Schleicher (1821-1868) developed pedigree theory according to evolve languages ​​analogous to the evolution of biological species from original languages ​​. With the help of the wave theory, the propagation of certain linguistic phenomena in language boundaries can be explained more easily than with evolutionary models, such as genetic drift.