Scientists have mapped the genetic roots of the Sindhi population across India and Pakistan, confirming their mixed ancestry from the Indus Valley periphery, Central Asian steppes and ancestral south Indian populations.
The researchers at Banaras Hindu University (BHU) have established that Sindhis trace 57-67 per cent of their genetic ancestry to the Indus Valley periphery, 25-30 per cent to the steppes, and 8-15 per cent to the ancestral south Indian populations.
Their study — the first large genomewide analysis of Sindhis — has also found evidence for a “founder effect” 49 generations ago, suggesting that the community has remained largely endogamous for nearly 1,500 years. The findings also suggest that marriages among close relatives have been more common among Pakistani Sindhis than among Indian Sindhis.
Earlier archaeological, historical and genetic studies had pointed to the Sindhis’ deep roots in the Indus Valley region and their mixed ancestry accumulated over the centuries, but comprehensive genomic data from the community has been limited.
“Our new genetic analysis suggests that the distinct genetic identity of the Sindhi population began to crystallise around 1,500 years ago,” Gyaneshwer Chaubey, a population geneticist at the BHU who led the study, told The Telegraph.
The study’s findings, set to appear in the journal Human Genetics on Monday, confirm strong genetic relationships between Sindhi populations in Pakistan and India, reflecting their shared ancestry despite geographic separation and revealing their root populations.
“Now, for the first time, we can put numbers to the Sindhis’ ancestral origins with the Indus Valley periphery contributing the largest share, followed by people from the steppes and the ancestral south Indian populations,” says Chanchal Devnani, a research scholar at BHU.
The Indus Valley periphery refers to farming populations who lived in the region between 6,000 and 4,000 years ago, while the steppe component reflects the pastoralists who migrated into south Asia around 2,000 BC, as estimated by other researchers in 2019.
The ancestral south Indian share traces back to the descendants of the first hunter-gatherers who settled in the subcontinent more than 40,000 years ago.
The BHU team analysed genomic data from 113 Sindhi people from seven states in India, combining it with archival genetic data from Sindhi people in Pakistan and genetic data from ancient populations, extracted by other scientists earlier from skeletal remains.
By analysing patterns of DNA inherited across generations, the researchers estimated that some of the major mixing between ancestral populations that make up present-day Sindhis occurred between 2,200 and 2,900 years ago.
The founder effect 49 generations — or around 1,500 years — ago meant that Sindhis from then onward remained largely endogamous, marrying within the community, and restricting fresh genetic inflow.
“But we also see a surprising difference in patterns of endogamy between Sindhis in Pakistan and in India,” Chaubey said.
The study found Pakistani Sindhis are genetically more homogeneous, reflecting a greater prevalence of marriages between close relatives, while Indian Sindhis, whose families have dispersed more widely across states and overseas since Partition appear to have more diverse marriage patterns.
The study’s coauthors included researchers Khushboo Gautam and Rajesh Rawal from Gujarat University.