Scientifically Speaking | DNA studies reveal how Indian languages evolved
For Indians, these findings offer a new perspective on our linguistic and cultural connections to the wider world.
When a Delhi resident chats in Hindi, they're participating in a linguistic legacy that stretches back about 6,500 years to the grasslands of present-day Russia. This connection is now backed by convincing genetic evidence, thanks to two landmark studies published in Nature this month that trace the origins of languages spoken by nearly half the world's population.
By analysing DNA from 435 ancient individuals, a team led by Harvard geneticist David Reich has solved one of humanity's enduring mysteries. They identified a specific group of people, dubbed the Caucasus Lower Volga (CLV) people, who lived in what is now Russia around 4500 BCE. These people inhabited the region between the Volga River and the northern Caucasus Mountains. Genetic evidence suggests they played a key role in the ancestry of early Indo-European-speaking populations. This linguistic family includes not only Hindi, Bengali, and Marathi, but also English, Spanish, and Persian.
"It's the first time we have a genetic picture unifying all Indo-European languages," said Iosif Lazaridis, a researcher at Harvard University and co-lead author of one of the studies. This discovery is particularly significant for India, where Indo-European languages are spoken by hundreds of millions of people across the northern and central regions of the subcontinent.
The story that emerges from genetic evidence reads like an ancient epic. The Caucasus Lower Volga people gave rise to another group known as the Yamnaya, who became the great spreaders of Indo-European languages.
The story of how researchers traced this connection lies partly in the burial practices of these ancient peoples. The CLV people and their descendants built large burial mounds called kurgans, which still dot the landscape of the Eurasian steppe. These monumental structures, which archaeologists have studied for generations, preserved ancient DNA that made this research possible.
"It's like a tracer dye," Reich explained, discussing how geneticists tracked these ancient migrations. "You can actually see Yamnaya ancestry everywhere these languages went." This genetic signature allowed researchers to track the spread of Indo-European languages with unprecedented precision through genetic analysis of skeletal remains, revealing detailed patterns of ancient human movement and mixing.
The Yamnaya were technological pioneers of their time. They were among the first to herd on horseback and among the earliest users of wheeled wagons. "I don't think we can even imagine what it was like for other people to see a wagon coming," says David Anthony, an emeritus professor at Hartwick College and co-lead author of the research. “It was moving across the landscape, creaking and groaning, pulling a ton of equipment. People had never seen anything like it before.”
This technological edge helped a small founding population undergo an extraordinary expansion between 3642-3374 BCE, growing from just a few thousand individuals to become one of the most influential populations in human history.
For India, this research has particular significance. A comprehensive genetic study by University of California Berkeley geneticist Priya Moorjani, published as a preprint in 2024, shows that most Indians derive their ancestry from three distinct sources: ancient Iranian farmers, Eurasian steppe pastoralists (connecting to the Yamnaya-related migrations), and South Asian hunter-gatherers.
The genetic evidence reveals that steppe-related ancestry, associated with later Yamnaya-descended groups such as the Andronovo and Sintashta cultures, entered South Asia around 2000 BCE. This ancestry is linked to the formation of early Indo-Iranian languages, which later evolved into Sanskrit and other Indic languages.
This complex genetic legacy helps explain why India hosts such remarkable linguistic diversity, with Indo-European languages like Hindi existing alongside completely unrelated language families like Dravidian and Austroasiatic.
When Sir William Jones first noted the similarities between Sanskrit, Latin, and Greek in 1786 while working in Kolkata, he could only speculate about their common origin. Today, through ancient DNA analysis combined with archaeological and linguistic evidence, we can trace the genetic signatures of the people who spoke the ancestor of these languages, following their movements across continents and millennia.
The technological innovations of the Yamnaya, particularly their mastery of horse riding and wagon technology, allowed them to transform the vast Eurasian grasslands into a network of connected communities. This mobile economy could sustain large populations over vast distances, facilitating the spread of both genes and languages in ways previously unimaginable.
For Indians, these findings offer a new perspective on our linguistic and cultural connections to the wider world. They demonstrate how technological innovations can drive massive cultural and linguistic changes, and how human populations have always been mobile and interconnected. The words we speak today carry echoes of ancient migrations, technological revolutions, and the deep interconnections of human history. This legacy is preserved in our genes and our languages.
Anirban Mahapatra is a scientist and author, most recently of the popular science book, When the Drugs Don’t Work: The Hidden Pandemic That Could End Medicine. The views expressed are personal.