Biologists using tools developed for drawing evolutionary family trees say that they have solved a longstanding problem in archaeology: The origin of the Indo-European family of languages.
The family includes English and most other European languages, as well as Persian, Hindi and many others. Despite the importance of the languages, specialists have long disagreed about their origin.Linguists believe that the first speakers of the mother tongue, known as proto-Indo-European, were chariot-driving pastoralists who burst out of their homeland on the steppes above the Black Sea about 4,000 years ago and conquered Europe and Asia. A rival theory holds that, to the contrary, the first Indo-European speakers were peaceable farmers in Anatolia, now Turkey, about 9,000 years ago, who disseminated their language by the hoe, not the sword.
The new entrant to the debate is an evolutionary biologist, Quentin Atkinson of the University of Auckland in New Zealand. He and colleagues have taken the existing vocabulary and geographical range of 103 Indo-European languages and computationally walked them back in time and place to their statistically most likely origin.
The result, they announced in Thursday’s issue of the journal Science, is that “we found decisive support for an Anatolian origin over a steppe origin.”
The researchers started with a menu of vocabulary items that are known to be resistant to linguistic change, like pronouns, parts of the body and family relations, and compared them with the inferred ancestral word in proto-Indo-European. Words that have a clear line of descent from the same ancestral word are known as cognates. Thus “mother,” “mutter” (German), “mat’ ” (Russian), “madar” (Persian), and “mater” (Latin) are all cognates derived from the proto-Indo-European word “mehter.”
Atkinson and his colleagues then scored each set of words on the vocabulary menu for the 103 languages. In languages where the word was a cognate, the researchers assigned it a score of one; in those where the cognate had been replaced with an unrelated word, it was scored zero.
The calculation pointed to Anatolia in southern Turkey as the most plausible origin — a region that had also been proposed as the origin of Indo-European by the archaeologist Colin Renfrew in 1987.