Herders spread Indo-European languages

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Highly mobile pastoralists likely contributed to the spread of the language group that evolved into English, say researchers.

Nomadic pastoralists from the Great Steppe helped spread the large group of languages that includes English, an analysis of ancient DNA confirms.

The findings, reported today in , gives weight to one of two competing hypotheses about where this language group came from.

"These results provide support for a steppe origin of at least some of the Indo-European languages of Europe," write the researchers in their paper.

Although English, Spanish, Russian, Urdu and Persian may sound very different, linguistic analysis suggests they all came from a common source, says lead author archaeo-geneticist Dr Wolfgang Haak of the University of Adelaide.

One idea is that this language group, now spoken throughout Europe, South Asia and the Middle East, spread with Neolithic farmers who migrated west from places like Turkey into Europe around 8000 years ago.

Another idea is that these languages must have emerged later because they include words for transport, such as wheel, a phenomenon that didn't emerge until later. Likely sources were the highly mobile cultures in the Great Steppe north of the Black Sea. These nomadic people were cattle herders who could have easily have brought language with them.

"They domesticated the horse in the Steppes around 5000 years ago and were probably using oxen-drawn carts to get around," says Haak.

But, he says, the subject has been controversial.

"The debate has been stuck for a while and has almost becomes a religious thing where you have believers of one side or the other," says Haak.

Archaeological evidence supports the 'Great Steppe' hypothesis, but until now, there has been a lack of evidence that herders migrated in large enough numbers to influence language, he says.

Ancient European DNA

Haak and colleagues analysed nuclear DNA from 69 ancient Europeans ranging from 3000 to 8000 years old, and combined this with existing data from another 25 ancient samples.

They found that there were three distinct genetic signals. The first was from 7000 to 10,000-year-old Stone-Age hunter-gatherers.

The second was from farmers that migrated from the Near East about 7500 years ago.

The third provided evidence of a migration of nomadic pastoralists west from the Great Steppe 4500 years ago.

Haak and colleagues found that the ancient central Europeans in their analysis shared 75 per cent of their DNA with these nomadic herders, suggesting these people had a large contribution to the development of language.

"It was not just a handful of people coming west. It was much much bigger than we anticipated," says Haak.

"If you have a genetic contribution that is that strong it's very very likely that language followed the same way and that what we currently speak in Europe is the aftermath of the most recent migration."

While modern speakers of Indo-European languages carry DNA markers from all three of these sources, the eastern pastoralist signal is most prominent in those from countries like Norway, Lithuania and Estonia. In countries like Greece, Spain and France, the signal is diluted out.

Haak says in future research he would like to test whether Steppe ancestry is evident in ancient Iranian or Indian populations.

He says one challenge will be finding well-preserved ancient DNA in subtropical environments.