Witzel quotes the surveys made by the Pakistani archaeologist Muhammad Rafiq Mughal which showed there were settlements on the Pakistani side of the … - Tony Joseph

The most exhaustive, multi-year geological study on the the possible reasons for the decline of the Harappan Civilization was published in a 2012 paper titled 'Fluvial Landscapes of the Harappan Civilization' which identified a clear cause: a prolonged drought that ultimately made monsoonal rivers go dry or become seasonal, affecting habitability along their courses. To quote: 'Hydroclimatic stress increased the vulnerability of agricultural production supporting Harappan urbanism, leading to settlement downsizing, diversification of crops and a drastic increase in settlements in the moister monsoon regions of the upper Punjab, Haryana and Uttar Pradesh.'

The residents of Mehrgarh who raised the first mud-brick homes of two or three rooms may not have realized it then, but they were laying the foundation for the first efflorescence of civilization in South Asia, called the Harappan Civilization, or the Indus Valley Civilization. It took about 4500 years or over 150 generations, for those humble mud-brick abodes to turn into the urban structures of a Harappa or a Mohenjo-daro or a Dholavira and there must have been many twists and turns along the way. But once agriculture took root, and modern humans started creating a surplus that they could save and invest, the wheels of history started spinning fast - which would, of course, lead to the invention of the wheel itself!

No human community is of exceptional status relative to others. None are children of God, or chosen people, unless all are. And none of us live upon the centre of the earth more than we live on its periphery, since we live on the surface of a globe. Nations as we understand them today are no older than a few centuries, and we are all interconnected - genetically, culturally and historically - far more than we imagine. And even 'time immemorial', it turns out, can increasingly be pinned down, dated, analysed and grasped. And when we do that, we get a far better understanding of our society and culture, and what went into their making.