Timeline of the Harappan Civilization is Pushed Back 2,500 Years as Researchers Find New Reason for Its Fall
A recent discovery suggests that the Indus Valley Civilization is at least 8,000 years old, not 5,500 as previously believed. Moreover, the researchers show that its power dwindled because of weaker monsoons.
According to The Times of India , the Indus Valley Civilization (also known as the Harappan Civilization) existed at least 8,000 years ago, making it one of the oldest known civilizations in the world – along with the Egyptian (7000BC to 3000BC) and Mesopotamian (6500BC to 3100BC) civilizations. The results of the study by scientists from IIT-Kharagpur and the Archaeological Survey of India (ASI) were published in the journal Nature on May 25.
So-called "Priest King" statue, Mohenjo-Daro, late Mature Harappan period, National Museum, Karachi, Pakistan. ( Mamoon Mengal/CC BY SA 1.0 )
The discovery may mean that history books will have to be rewritten because earlier it was believed that the Indus Valley civilization was only 5,500 years old. The leader of the project, Anindya Sarkar, also believes that their research provides evidence that the civilization did not fall due to climate change but was influenced by it. The team discovered the oldest pottery from the civilization, which was made during the period called Early Mature Harappan (c. 6,000 years ago) and the pre-Harappan Hakra phase - as far back as 8,000 years.
The researchers set out to explore Lothal, Dholavira, and Kalibangan in India. They also dug in a mostly unexplored site, Bhirrana. They wanted to prove that the Indus Valley civilization spread to other Indian sites like Bhirrana and Rakhigarrhi in Haryana, apart from the known locations of Harappa and Mohenjo Daro in Pakistan. However, they discovered something much more impressive.
Panoramic view of the excavation of mature Harappan stage at Bhirrana view from North-east. ( Archeological Survey of India )
The team unearthed large quantities of animal remains; including horn cores and the teeth and bones of cow, goat, antelope, and deer. These remains were put through Carbon 14 testing. Arati Deshpande Mukherjee of Deccan College, who helped analyze the finds along with researchers at the Physical Research Laboratory in Ahmedabad, explained:
"We analysed the oxygen isotope composition in the bone and tooth phosphates of these remains to unravel the climate pattern. The oxygen isotope in mammal bones and teeth preserve the signature of ancient meteoric water and in turn the intensity of monsoon rainfall. Our study shows that the pre-Harappan humans started inhabiting this area along the Ghaggar-Hakra rivers in a climate that was favourable for human settlement and agriculture. The monsoon was much stronger between 9000 years and 7000 years from now and probably fed these rivers making them mightier with vast floodplains.''
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The team believes that the civilization spread over a vast expanse of India, but the only evidence for this came from British excavations. The most recent research by the Indian team also suggests that climate change was probably not the sole cause for the collapse of the civilization. The people of the Harappan Civilization did not seem to give up despite the weakening monsoon. They did not disappear, but they changed their farming practices by switching from water-intensive crops to drought-resistant crops. This was the beginning of a new era in the civilization’s existence.
Diorama reconstruction of everyday life in Indus Valley Civilization, New Delhi. ( Biswarup Ganguly/CC BY 3.0 )
The researchers believe that this change in their subsistence strategy - shifting crop patterns from the large-grained cereals like wheat and barley during the early part of the intensified monsoon to drought-resistant species of small millets and rice in the later part of declining monsoon - played a large role in the civilization’s fall as well. Moreover, the researchers discovered that from 7,000 years ago onwards, the monsoons became progressively weaker.
Map of Northwest India and Pakistan showing the locations of main Harappan settlements including phosphate sampling site of Bhirrana, Haryana, IWIN precipitation sampling station at Hisar and two paleo-lakes Riwasa and Kotla Dahar studied earlier. Black arrow indicates the direction of monsoon moisture transport from Bay of Bengal. ( Sarkar et al )
Some of the first accounts of the Indus Valley Civilization were recorded in the 1800s by the British. In 1826, the British army deserter James Lewis noticed the presence of ruins in a small town in Punjab called Harappa. It was because of this discovery that the civilization was called ‘Harappan.’