Africa birthplace of human language

Languages from central and southern Africa have the most sounds of any in the world, which suggests that the area is the original birthplace of human language.

Researchers looked at 504 human languages and found a wide range in the number of distinct sound units (called phonemes) in them. African languages have the most distinct sounds. Some languages that evolved at the end of human's long trek to colonize the planet, in South American and islands in the Pacific, have the fewest.

Linguistic analysis shows that languages tend to start with large numbers of sounds and become simpler over time as populations 'bottle-neck" (become very small and then grow again.) The more people who speak a language, the more sounds it as. The researcher, Quentin Atkinson at the University of Auckland in New Zealand, suggests that as small groups slowly moved out of Africa, the number of sounds in their languages diminished. As this happened over and over again across many milenia, the total number of sounds in the languages that developed decreased.

The research also fits with patterns of human genetic variation - the further from Africa, the less genetic diversity. Atkinson's paper is published in this week's edition of the journal Science.