Ancient DNA from India’s Rakhigarhi archaeological site is telling volumes about the destiny of the mysterious Indus Valley Civilization.
Around 3000 BC, Neolithic hunters in northern Scotland began settling into new sedentary lifestyles and erected vast stone circles and burial chambers, while in Egypt at this time the first pyramids were built. Meanwhile, the Harappans of South Asia, better known as the Indus Valley Civilization , erected massive brick housing complexes connected with extensive canal systems , yet hardly anything was known of the actual people, until now.
At its peak the civilization covered northwestern India and parts of eastern Pakistan and besides ancient Egypt and Mesopotamia it was one of the world’s first urban agricultural societies with five cities holding a population of between 1 million and 5 million. The series of collapses of ancient Egyptian dynasties is relatively well known, but the causes of the fall of the Harappan civilization around 1700 BC are much less understood, and that’s why this new genome research of an ancient Harappan is making the headlines.
Hot Climates Scorch Scientists Efforts
The team of researchers, led by geneticist David Reich from Harvard University and archaeologist Vasant Shinde at Deccan College in Pune, India, published their new study on Cell, based on studies at the Indus site known as Rakhigarhi, about 93 miles (150 kilometers) northwest of modern-day Delhi. “More than 60 skeletal pieces, including numerous petrous bones” were tested before the scientists successfully found and extracted a sample of ancient DNA, according to the scientists report.
Rakhigarhi archaeological site, India. (Homeric Origins / YouTube)
An article in Science Mag explains that the region’s hot climate quickly degrades genetic material and while hundreds of skeletons have been unearthed in the Indus Valley this is the first one to hold valuable DNA, which the report says was sequenced more than 100 times to piece together what was called a “relatively complete genome”. Reich said, “There’s no doubt this is the most intensive effort we’ve ever made to get ancient DNA from a single sample.” While the findings say little about ‘why’ the society collapsed a new story is revealed about its continuing genetic legacy in modern Indians.
5,000-Year-Old Harappan Migrants
The DNA was sampled from an individual that was most likely female, who was found buried among dozens of ceramic bowls and vases dated to between 2800 and 2300 BC. Her genome closely matched DNA samples from 11 other individuals who had been found in Iran and Turkmenistan, with whom the Harrapans traded. Because the 11 individuals had ”little in common genetically with others buried in their regions,” Reich and researchers concluded that they were most likely Harappan migrants .
- The Helpful Harappan Explains How Ancient Indus Valley Technology Could Solve Many of Today’s Problems
- Archaeologists may have located ancient port dating back 4,500 years in Goa
- Ancient City of Mohenjo Daro Has Survived 5 Millennia but May Disappear in 2 Decades
The Bronze Age spread of Yamnaya Steppe pastoralist ancestry into two subcontinents—Europe and South Asia. (Science / Fair Use )
The researchers next compared these genetic signatures against DNA from ancient Eurasians as well as modern populations and the researchers made an ‘Indus family tree’ which reveals in its bowers that “genetic stock from the ancient Harrapan civilization can be found in most of today’s Indian population ”, according to the report in Cell.
Ancient Origins of Harappans Rewritten
What’s more, the paper also says that modern people from north India have “the genetic marks” of Harappans having interbreed with animal herders living on the Eurasian steppe , “moving southward around 2000 BC”. And explaining the once-perplexing genetic link between Europeans and South Asians those steppe herders must have carried European DNA, from previous interbreeding events, and over the next three millennia the groups in north and south India intermixed, leading to the current population’s “complex ancestral mix”.
Evidence suggests Rakhigarhi was a major Harappan city center. (Homeric Origins / YouTube)
A side observation which excites scientists provides new answers for why ancient Iranian DNA is found in modern South Asians, and how agriculture got to the Indian subcontinent. Contrary to the current belief that the world’s first farmers emerged from what is today Iran, about 10,000 years ago, and integrated with South Asian hunter-gatherers, the new study suggests the Iranian-related DNA “predates the rise of agriculture in Iran by some 2000 years”.
This means ancient Iranian DNA came from “interbreeding with 12,000-year-old hunter-gatherers, not more recent farmers”, Reich explains in the paper. All this, from one tiny sample of DNA.
Top image: Representation of discovery of the skeleton at the Rakhigarhi archaeological site. Source: Elena / Adobe Stock.
By Ashley Cowie