The recent revisions made by the National Council for Education Research and Training (NCERT) to the history textbooks for Class 12 students, particularly concerning the origins and decline of the Harappan Valley civilization, reflect a significant shift in perspective based on recent archaeological and genetic studies.

One of the key changes introduced by NCERT is the assertion that recent studies of ancient DNA obtained from archaeological sources at Rakhigarhi, an Indus Valley site in Haryana, have ruled out Aryan immigration. This challenges previous theories regarding the arrival of the Aryans into the Indian subcontinent and calls for further research into the relationship between the Harappan civilization and the Vedic people.

Additionally, NCERT has emphasized the "unbroken continuity" of the Harappan civilization over 5000 years, suggesting a revision of previous assumptions about breaks or disruptions in its development. This shift in perspective is supported by recent archaeological evidence that highlights the longevity and resilience of Harappan settlements.

Furthermore, NCERT has introduced the idea that the Harappans may have practiced some form of democratic governance, based on interpretations of archaeological findings. This adds a new dimension to our understanding of ancient Harappan society and its political structures.

Overall, these revisions reflect NCERT's commitment to incorporating the latest research findings and scholarship into history textbooks, providing students with a more nuanced and up-to-date understanding of India's rich cultural and historical heritage.