Under a project called ‘Archaeology of the Ramayana Sites’ excavations were carried out between 1975 and 1986 at five sites, viz. Ayodhya, Sringavera… - B. B. Lal

Lal (1997, 9) considers the Sarasvati to have been alive in Kalibangan in the third millennium B.C.E. and dried up at the turn of the millennium: "The Sarasvati dried up around 2000 BC. This clearly establishes that the Rigveda, which speaks of the Sarasvati as a mighty flowing river, has to be assigned to a period prior to 2000 BC. By how many centuries it cannot be said for certain" (Lal, forthcoming).

The obvious result [of the diversion of the Sarasvatī’s waters into the Yamuna system] was the migration of the [Harappan] people towards the north-east where some water was still available in the uppermost reaches of the Sarasvatī and Ghaggar and further east in the upper plains of the Gangā-Yamunā Doāb.’

Here it may perhaps be stated straightaway that so far no unimpeachable evidence has been adduced to prove or even to disprove either of the above-mentioned theories. (about Indo-Aryan invasions or migrations) In such a situation there is little wonder that guesses run wild and pride and prejudice safely prey on them.