Almost half of the world’s population speaks an Indo-European language, including German. But when and where did the language family emerge and how did it diversify and spread? An analysis of 161 modern and non-modern languages now shows that the language family probably originated around 8,120 years ago south of the Caucasus, later branching out into northern steppe regions and from there spread across Eurasia. The results reconcile previous hypotheses and also agree with DNA evidence for the spread of the tribes involved.
Most of the languages spoken in Europe today belong to the Indo-European language family. It includes the Germanic, Romance, Slavic, Baltic and Celtic languages, as well as Greek, Albanian, Armenian and the Indo-Iranian language group. The designation Indo-European, partly also Indo-European, originally referred to the assumed geographical distribution of the languages. Today, however, Indo-European languages are spoken far beyond Europe in many parts of the world – not least due to colonialism – and it has been revealed that the origins of the language family also lie outside of Europe.
Farmers or steppe peoples?
However, when and where exactly the language family emerged has been a matter of debate up to now. A common hypothesis, the so-called steppe hypothesis, assumed that the origins of the language family lie around 6,500 years ago in the Pontic-Caspian steppe. According to this, nomadic steppe peoples on horseback spread the languages around 5,000 years ago. Another hypothesis, the so-called Agrarian hypothesis, places the origin of the Indo-European languages 8,500 to 9,500 years ago south of the Caucasus in the Fertile Crescent in Anatolia. According to this, the languages of this family spread across Europe with agriculture.
A team led by Paul Heggarty from the Max Planck Institute for Evolutionary Anthropology in Leipzig has now got to the bottom of the origins of our languages. To do this, the researchers analyzed more than 100 modern and 52 non-modern languages for related word origins in the core vocabulary. In this way, they used linguistic methods to create a family tree of the languages. In addition, they also included genetic clues that, based on ancient DNA, provide information about how certain historical people groups spread.
Linguistic affinity under scrutiny
“Our results do not fully agree with either the steppe or the agricultural hypothesis,” reports the team. “Our analyzes revealed that the roots of the Indo-European languages go back around 8,120 years – too early for the steppe hypothesis.” At the same time, however, evidence from ancient DNA suggested that the early speakers of many branches of the language family have their origins in the steppe. In the Anatolian and Greek regions as well as in large parts of Asia, however, there were no indications of such a steppe origin.
The relationships between the languages also raised questions. “Previous analyzes assumed that modern languages developed directly from earlier written languages, rather than from parallel, spoken variations,” the researchers explain. This would have resulted in a distorted picture of the language relationship. The new analysis, on the other hand, abandoned this assumption and resulted in a new family tree that is more consistent with evidence from ancient DNA.
Combination of the hypotheses
Thus, in line with the agrarian hypothesis, the Indo-European languages actually arose south of the Caucasus, around 8,120 years ago. Some branches of the language family, including the Indo-Iranian language group and Greek and Albanian, branched directly from there. About 7,000 years ago, speakers of the then Indo-European language arrived in the Pontic-Caspian steppe north of the Caucasus. “The steppe thus forms the secondary homeland for some branches of Indo-European that came to Europe with later expansions,” explain Heggarty and his team. The Germanic, Baltic and Celtic languages, among others, probably go back to the steppe peoples.
“Thus, the combination of language phylogenetics and ancient DNA suggests that the solution to the enigma of the Indo-European languages lies in a mixture of the agrarian and the steppe hypothesis,” the team summarizes.
Source: Paul Heggarty (Max Planck Institute for Evolutionary Anthropology, Leipzig) et al., Science, doi: 10.1126/science.abg0818