Areal feature
In linguistics, areal qualities are elements dual-lane up by languages or dialects in the geographic area, especially when such assigns are non descended from the proto-language, or, common ancestor language. That is, an areal feature is contrasted to lingual-genealogically determined similarity within the same language family. Features may diffuse from one dominant Linguistic communication to neighbouring languages see "sprachbund".
Genetic relationships are represented in the family tree model of language change, together with areal relationships are represented in the wave model.