It's been an established theory that the Vedas and the caste system was a result due to an invasion by an Indo-European group of people. The Aryan Invasion with German Max Muller as one of its original proponents has been more or less accepted in the field of Indian History.
However recent geological and archealogical findings (including the remains of the Saraswati River) have put into question the whole Aryan Invasion theory. There is a growing chain of thought that the Aryan Invasion never occurred agressively promoted by the Hindu Right wing groups.
After doing my bit of reading including the book "In Search of The Cradle of Civilization" by Feuerstein, Kak and Frawley, my thoughts tend to agree that the whole Aryan Invasion Theory never occured. Though this right wing theory is debunked by emminent indologist's like Romila Thapar, it should be addressed with an open mind without being influenced by the various ideologies.
On that note, here's wishing everyone a Very Happy New Year !
May it bring peace to all