Language - a clue to the human diaspora?

I've long been interested in linguistics: the study of human language. I'm strictly an amateur in the field, but I've tried to keep abreast of recent developments. One of them is very intriguing, as the Daily Mail reports.

Every language in the world - from English to Mandarin - evolved from a prehistoric 'mother tongue' first spoken in Africa tens of thousands of years ago, a new study reveals.

After analysing more than 500 languages, Dr Quentin Atkinson found compelling evidence that they can be traced back to a long-forgotten dialect spoken by our Stone Age ancestors.

The findings don't just pinpoint the origin of language to Africa - they also show that speech evolved at least 100,000 years ago, far earlier than previously thought.

. . .

There is now compelling evidence that the first modern humans evolved in Africa around 200,000 to 150,000 years ago.

Around 70,000 years ago, these early humans began to migrate from the continent, eventually spreading around the rest of the world.

Although most scientists agree with this 'Out of Africa' theory, they are less sure when our ancestors began to talk.

Some have argued that language evolved independently in different parts of the world, while others say it evolved just once, and that all languages are descended from a single ancestral mother tongue.

Dr Atkinson, of Auckland University, has now come up with fascinating evidence for a single African origin of language.

In a paper published today in Science, he counted the number of distinct sounds, or phonemes, used in 504 languages from around the world and charted them on a map.

The number of sounds varies hugely from language to language. English, for instance has around 46 sounds, some languages in South America have fewer than 15, while the San bushmen of South Africa use a staggering 200.

Dr Atkinson found that the number of distinct sounds in a language tends to increase the closer it is to sub-Saharan Africa.

Phonemes in languages, following human migration paths from Africa (click the map for a larger view)

He argues that these differences reflect the patterns of migration of our ancestors when they left Africa 70,000 years ago.

Languages change as they are handed down from generation to generation.

In a large population, languages are likely to be relatively stable - simply because there are more people to remember what previous generations did, he says.

But in a smaller population - such as a splinter group that sets off to find a new home elsewhere - there are more chances that languages will change quickly and that sounds will be lost from generation to generation.

Professor Mark Pagel, an evolutionary biologist at Reading University, said the same effect could be seen in DNA.

Modern-day Africans have a much greater genetic diversity than white Europeans who are descended from a relatively small splinter group that left 70,000 years ago.

'The further you get away from Africa, the fewer sounds you get,' he said.

'People have suspected for a long time that language arose with the origin of our species in Africa and this is consistent with that view.'

There's more at the link.

We should note that Dr. Atkinson's research focuses specifically on spoken language. Actual communication probably predated spoken language by hundreds of thousands of years. Signs and symbols can be widespread without the need for spoken language - just look at how the more intelligent animals (e.g. apes) have evolved such communications systems.

If further research confirms Dr. Atkinson's theories, this will be a substantial advance in our understanding of human evolution, migration and social development.

Peter