 The Aryan Invasion theory has been discarded in mainstream scholarship since the 1980s, and replaced by more sophisticated models, referred to as the Indo-Aryan migration theory.It posits the introduction of Indo-Aryan languages into South Asia through migrations of Indo-European-speaking people from their "Urheimat" (original homeland) in the Pontic Steppes via Central Asia into the Levant (Mitanni), south Asia, and Inner Asia (Wusun and Yuezhi).It is part of the Kurgan-hypothesis/Revised Steppe Theory, which further describes the spread of Indo-European languages into western Europe via migrations of Indo-European speaking people.