Why do scholars describe Indo-Aryan movement into South Asia as a series of migrations rather than a single invasion?

Modern scholarship has largely moved away from the "Aryan invasion" theory, which is now considered discredited. Instead, historians and linguists describe the entry of Indo-Aryan speakers into the Indian subcontinent as a series of gradual migrations.12

This shift in perspective is supported by several factors:

• Lack of Archaeological Evidence: There is no definitive archaeological evidence of a violent conquest or invasion. The decline of the Indus civilization is not attributed to such an event, and there is a high degree of physical continuity between Harappan and post-Harappan societies.31
• Cultural Synthesis: Rather than a sudden replacement of populations, evidence suggests a long-term process of cultural interaction and integration between the newcomers and the indigenous inhabitants. This interaction eventually led to a new cultural synthesis, forming the basis of the Vedic period.32
• Linguistic and Historical Complexity: The migration was not a single, monolithic event but a continuing spread of people over several centuries, beginning around the 2nd millennium BCE. This complex process involved nomadic pastoralists moving into the region, eventually leading to the linguistic landscape seen in South Asia today.312