Many Tamils trace their origins to the people of Mohenjodaro in the Indus Valley around 6000 years before the birth of Christ. There is, however, a need for further systematic study of the history of the early Tamils and proto Tamils.
"Dravidians, whose descendents still live in Southern India, established the first city communities, in the Indus valley, introduced irrigation schemes, developed pottery and evolved a well ordered system of government." (Reader's Digest Great World Atlas, 1970)
Clyde Ahmad Winters, who has written extensively on Dravidian origins commented:
"Archaeological and linguistic evidence indicates that the Dravidians were the founders of the Harappan culture which extended from the Indus Valley through northeastern Afghanistan, on into Turkestan. The Harappan civilization existed from 2600-1700 BC. The Harappan civilization was twice the size the Old Kingdom of Egypt. In addition to trade relations with Mesopotamia and Iran, the Harappan city states also had active trade relations with the Central Asian peoples."
He has also explored the question whether the Dravidians were of African origin. (Winters, Clyde Ahmad, "Are Dravidians of African Origin", P.Second ISAS,1980 - Hong Kong:Asian Research Service, 1981 - pages 789- 807) Other useful web pages on the Indus civilisation (suggested by Dr.Jude Sooriyajeevan of the National Research Council, Canada) include the Indus Dictionary.
At the same time, the Aryan/Dravidian divide in India and the 'Aryan Invasion Theory' itself has come under attack by some modern day historians. (see also Sarasvati-Sindhu civilisation; 'Hinduism: Native or Alien to India')
Professor Klaus Klostermaier in 'Questioning the Aryan Invasion Theory and Revising Ancient Indian History' commented:
"India had a tradition of learning and scholarship much older and vaster than the European countries that, from the sixteenth century onwards, became its political masters. Indian scholars are rewriting the history of India today. One of the major points of revision concerns the so called 'Aryan invasion theory', often referred to as 'colonial-missionary', implying that it was the brainchild of conquerors of foreign colonies who could not but imagine that all higher culture had to come from outside 'backward' India, and who likewise assumed that a religion could only spread through a politically supported missionary effort.
While not buying into the more sinister version of this revision, which accuses the inventors of the Aryan invasion theory of malice and cynicism, there is no doubt that early European attempts to explain the presence of Indians in India had much to with the commonly held Biblical belief that humankind originated from one pair of humans - Adam and Eve to be precise ..."
Hinduism Today concluded in Rewriting Indian History - Hindu Timeline:
"Although lacking supporting scientific evidence, this (Aryan Invasion) theory, and the alleged Aryan-Dravidian racial split, was accepted and promulgated as fact for three main reasons. It provided a convenient precedent for Christian British subjugation of India. It reconciled ancient Indian civilisation and religious scripture with the 4000 bce Biblical date of Creation. It created division and conflict between the peoples of India, making them vulnerable to conversion by Christian missionaries."
"Scholars today of both East and West believe the Rig Veda people who called themselves Aryan were indigenous to India, and there never was an Aryan invasion. The languages of India have been shown to share common ancestry in ancient Sanskrit and Tamil. Even these two apparently unrelated languages, according to current "super-family" research, have a common origin: an ancient language dubbed Nostratic."
REFERENCE TAKEN FROM : http://www.tamilnation.org/heritage/index.htm