A cultural tradition refers to persistent configurations o f basic technologies and cultural systems as well as structure within the context of tempo… - Jim G. Shaffer

Pollen cores from Rajasthan seem to indicate that by the mid-third milennium BC, climatic conditions of the Indus Valley area became increasingly arid. Data from the Deccan region also suggests a similar circumstance there by the end of the second millennium BC. Additionally, and more directly devastating for the Indus Valley region, in the early second millennium BC, there was the capture of the Ghaggar-Hakra (or Saraswati) river system (then a focal point of human occupation) by adjacent rivers, with subsequent diversion of these waters eastwards. At the same time, there was increasing tectonic activity in Sindh and elsewhere. Combined, these geological changes meant major changes in the hydrology patterns of the region. These natural geologic processes had significant consequences for the food producing cultural groups throughout the greater Indus Valley area. Archaeological surveys have documented a cultural response to these environmental changes creating a “crisis” circumstance...

We have already noted that the scholarly paradigm of the eighteenth and nineteenth centuries in conflating language, culture, race, and population movements has continued, with historical linguistic scholars still assiduously attempting to reconstruct a Proto-Indo-European language and attempting to link that language to a specific “homeland,” in order to define population migration away from that seminal geographic base

At present, the archaeological record indicates no cultural discontinuities separating PGW from the indigenous protohistoric culture. That is, PGW culture represents an indigenous cultural development and does not reflect any cultural intrusion from the West, that is, an Indo-Aryan invasion. Therefore, there is no archaeological evidence corroborating the fact of an Indo-Aryan invasion.