Russell Gray and Quentin Atkinson, psychologists at the University of Auckland in New Zealand have retraced the family tree of so-called Indo-European languages – a linguistic classification that covers scores of tongues ranging from Faroese to Hindi by way of English, French, German, Gujarati, Nepalese and Russian.
They built their language tree on the same principles as the theory of genetic evolution.
According to this idea, words, likes genes, survive according to their fitness.
Imported words take root in a language in response to evolutionary pressures or if they answer a need, and words can also fall out of use, rather like "silent" DNA that appears to be a relic in the genome and serves no known purpose.
The languages that are spoken and written today are the result of historical layering, of addition and deletion, that can be carefully scraped away to trace their previous sources, Gray and Atkinson suggest in the British scientific journal Nature.
The similarity is phylogeny – the reconstruction of the evolutionary history of organisms.
Using a parallel method, the two academics turned back the clock on 87 languages, using sophisticated software to trace the path taken by 2499 "cognates" – fundamental words in each language that are presumed to derive from a common ancestor.
Their study produces an estimated age-range for the very first Indo-European language of between 7800 and 9800 years ago, among rural communities who lived in modern-day Anatolia and for whom there is already an impressive array of archaeological evidence.
Successful pioneers in agriculture, these people migrated westwards and eastwards and the languages evolved accordingly, becoming the tongues that today are so diverse that they would seem to share no common link.
"The pattern and timing of expansion…is consistent with the Anatolian farming theory," Gray and Atkinson suggest.
About 6000 years ago, the western branch of linguistic migration began to fork into smaller branches, according to their calculations.
The branches progressively became the Celtic language 2900 years ago and the Germanic languages of northern Europe including rudimentary English 1750 years ago.
As for the eastern branch, the biggest fork occurred about 4600 years ago.