BCE, persistent drought caused the population of the Indus Valley to scatter from large urban centres to villages. Indo-Aryan tribes moved into the Punjab

The passage highlights a critical moment in ancient history, specifically around 2000 BCE, when a persistent drought contributed to significant demographic changes in the Indus Valley region. As the environmental conditions deteriorated, the large urban centers, which were previously bustling with life and commerce, became less sustainable for supporting large populations. This led to a mass movement of people from these urban areas to smaller, more manageable village settings where subsistence farming might have been more feasible.

The mention of Indo-Aryan tribes migrating into Punjab adds another layer of complexity to this transition. The movement of these tribes is often associated with the spread of new languages, cultures, and technological practices, which could have also influenced the socio-political landscape of the region. This migration marks a period of significant cultural fusion and transformation that would shape the history of South Asia.

Overall, the dual phenomena of environmental challenges and migration underline the intricate relationship between human societies and their environments, as well as the impact of such changes on the cultural dynamics of the region.