The document discusses the emergence and evolution of the Aryan debate theory over time. There were two main theories: 1) Aryans originated in Central Asia and invaded India, and 2) Aryans originated in India and later migrated west. The first theory proposed by Max Mueller of an original Aryan homeland in Central Asia was later adapted differently by missionaries, Hindu nationalists, and others to suit their social and political agendas. Archaeological evidence from the Indus civilization challenged this theory, and it is now understood that widespread contacts existed between northwestern India, Iran, and Central Asia in ancient times without a massive migration or invasion.