The Collision that Formed India

What genetics reveals about Indian origins

01 October 2018


In the oldest text of Hinduism, the Rig Veda, the warrior god Indra rides against his “impure enemies,” or dasa, in a horse-drawn chariot, destroys their fortresses, or pur, and secures land and water for his people, the arya, or AryaComposed between 4,000 and 3,000 years ago in Old Sanskrit, the Rig Veda was passed down orally for some two thousand years before being written down, much like the Iliad and Odyssey in Greece, which were composed several hundred years later in another early Indo-European language. The Rig Veda is an extraordinary window into the past, as it provides a glimpse of what Indo-European culture might have been like in a period far closer in time to when these languages radiated from a common source. But what did the stories of the Rig Veda have to do with real events? Who were the dasa, who were the arya, and where were the fortresses located? Did anything like this really happen? There was tremendous excitement about the possibility of using archaeology to gain insight into these questions in the 1920s and 1930s. In those years, excavations uncovered the remains of an ancient civilisation, walled cities at Harappa, Mohenjo-daro, and elsewhere in the Punjab and Sind that dated from 4,500 to 3,800 years ago. These cities and smaller towns and villages dotted the valley of the river Indus in present-day Pakistan and parts of India, and some of them sheltered tens of thousands of people. Were they perhaps the fortresses, or pur, of the Rig Veda?

Indus Valley Civilisation cities were surrounded by perimeter walls and laid out on grids. They had ample storage for grain supplied by farming of land in the surrounding river plains. The cities sheltered craftspeople skilled in working clay, gold, copper, shell and wood. The people of the Indus Valley Civilization engaged in prolific trade and commerce, as reflected in the stone weights and measures they left behind, and their trading partners, who lived as far away as Afghanistan, Arabia, Mesopotamia and even Africa. They made decorative seals with images of humans or animals. There were often signs or symbols on the seals whose meaning remains largely undeciphered.

Since the original excavations, many things about the Indus Valley Civilisation have remained enigmatic, not only its script. The greatest mystery is its decline. Around 3,800 years ago, the settlements of the Indus dwindled, with population centres shifting east toward the Ganges plain. Around this time, the Rig Veda was composed in Old Sanskrit, a language that is ancestral to the great majority of languages spoken in northern India today and that had diverged in the millennium before the Rig Veda was composed from the languages spoken in Iran. Indo-Iranian languages are in turn cousins of almost all of the languages spoken in Europe and with them make up the great Indo-European language family. The religion of the Rig Veda, with its pantheon of deities governing nature and regulating society, had unmistakable similarities to the mythology of other parts of Indo-European Eurasia, including Iran, Greece and Scandinavia, providing further evidence of cultural links across vast expanses of Eurasia.

Some have speculated that the collapse of the Indus Valley Civilisation was caused by the arrival in the region of migrants from the north and west, who spoke Indo-European languages—the so-called Indo-Aryans. In the Rig Veda, the invaders had horses and chariots. We know from archaeology that the Indus Valley Civilization was a pre-horse society. There is no clear evidence of horses at their sites, nor are there remains of spoke-wheeled vehicles, although there are clay figurines of wheeled carts pulled by cattle. Horses and spoke-wheeled chariots were the weapons of mass destruction of Bronze Age Eurasia. Did the Indo-Aryans use their military technology to put an end to the old Indus Valley Civilisation?

Keywords: ancestry Harappa genetics Indus valley civilisation DNA Indian origins Indo-European culture Rig Veda Africa Eurasia European