To the untrained ear, languages like English, Dutch, Spanish, Russian, Greek and Hindi might all sound very different from one another but in fact they show remarkable similarities. Where the English use mother, for example, we find moeder in Dutch, madre in Spanish, mat’ in Russian, mitéra in Greek and Māṁ in Hindi. On the basis of many systematic similarities like this, scholars have concluded that these languages, and hundreds of others from across Europe and the Near East, are in fact all related, having “sprung from some common source, which, perhaps, no longer exists”. Dubbed the Indo-European language family, this group of linguistic relatives stretches from Icelandic in the west to Singhalese, spoken in Sri Lanka, in the east. However, despite over 200 years of careful scholarship, the origins of the family remain controversial. In a commentary in Science on the expansion of the world’s languages, Jared Diamond and Peter Bellwood call the origin of Indo-European “the most well-studied and yet still most recalcitrant problem in historical linguistics”.
Two competing theories
There are two main competing hypotheses for the homeland of the Indo-European languages. The conventional view, first put forward by Marija Gimbutas, links Proto-Indo-European (the hypothesized ancestral Indo-European tongue) with archaeological evidence for the expansion of a semi-nomadic, pastoralist people, known as the Kurgans, from their homeland in the Pontic steppes out across Europe and the Near East during the fifth and sixth millennia BP.
The second theory, proposed by archaeologist Lord Professor Colin Renfrew, holds that the language family spread with the expansion of agriculture from Anatolia between 8000 and 9500 years ago. A spread of languages with agriculture has also been argued in the Pacific, Southeast Asia, and sub-Saharan Africa.
Each theory implies a different location and time depth for the Indo-European language family – on the Pontic steppes 5000-6000 years ago or in Anatolia 8000-9500 years ago. We set out to test between these hypotheses by modelling the evolution of the language family through space and time and asking whether one scenario was significantly more likely than the other.