TODAY SOME 6,000 languages are spoken across the globe, but just as science has broadly accepted genetic evidence that modern humans share a common origin in Africa, is it possible that languages too share a common single source, a mother of all mother tongues? Yes, says Quentin Atkinson, a University of Auckland biologist, in an elegantly persuasive study of 504 languages in the journal Science.
Using mathematical techniques that have been employed to track genetic diversity, Atkinson has found an important statistical correlation between the variety of sounds, or “phonemes”, used in individual languages and their distance from a likely common source in southern Africa some 50,000 years ago. Dialects with the most phonemes – distinct sound building blocks like “c”, “a”, and “tch” – are spoken in Africa while those with the fewest are spoken in South America and on tropical islands in the Pacific.
Thus, at one end of a broad scale, come the click-using languages of Africa like those of the Bushmen of the Kalahari with more than 100 phonemes, while Hawaiian, towards the far end of the human migration route out of Africa, has only 13. English has about 45 phonemes, Mandarin, 32. It is a pattern that appears to mirror the genetic variations that have been used to support the “out of Africa” thesis which posits man emerging first on the continent about 200,000 years ago before the beginning of worldwide migration, perhaps 50-70,000 years ago.
Recent studies have shown that phoneme diversity in language increases with population size, but diminishes in the small groups that break away to migrate. Cumulative migrations, Atkinson argues, will produce the patterns he found, what biologists call a “serial founder effect”, a repeated reduction in diversity with distance from the source. “One of the big questions is whether there was a single origin of language,” or if it emerged in parallel in different locations, says Atkinson. “This suggests there was one major origin in Africa.”
His technique allows him to look at modern languages to study the relics of the components of languages 50,000 to 70,000 years ago in a way that traditional language trees of words and structures cannot – the oldest language tree so far reconstructed, that of the Indo-European family, which includes English, goes back 9,000 years at most. It is an approach that is not universally accepted among linguists, but the enthusiastic response of peers will certainly prompt follow-up studies.