by Tom Thompson
In many ways the origins of spoken language remain the murkiest of all the important developments for our distant past. The ephemeral nature of speech means that we have nothing physical to excavate or examine, and no way to directly prove its existence.
It’s difficult to find biological components involved in speech. The hyoid bone – which allows the tongue and larynx to work together -- gives a clue, but it’s attached to soft tissue so that as the body decomposes. The hyoid can shift position, or even disappear. The FOXP2 gene provides some clues to speaking ability. But the reach in time of sequence DNA across thousands of years is limited.
The Broca’s area of the brain (in the frontal lobe) is important, as is the Werniche’s area (in the temporal lobe). They seem to be responsible for the identification and subsequent sorting of incoming words. But all of these brain parts are internal, so that identifying them on a fossil-skull endocast is difficult.
What even prompted the origins of speaking ability is similarly murky. Evolutionary biology and its focus on social learning and cumulative cultural adaptation have been instructive. Our ancestors, the Neanderthals and the Homo erectus, our immediate ancestors, were initially confined to small parts of the world. But when our species arose about 200,000 years ago, sometime after that, perhaps resulting from a sudden neurological change, we walked out of Africa and spread around the world, occupying nearly every habitat on Earth. And so we prospered in a way that no other animal has. Language really is the most potent trait that we have ever evolved.
A twist in our understanding of that trait is that we use our speaking ability, not just to cooperate, but also to draw rings around our cooperative groups and to establish identities, and perhaps to protect our knowledge and wisdom and skills from eavesdropping from outsiders. Two of the genius analysts in these areas are Mark Pagel of the University of Reading, the evolutionary biologist, and Professor Quentin Atkinson at the University of Auckland. Professor Atkinson is an expert at applying mathematical methods to linguistics. Together the two and their team have detected ancient signals that point to the origins of speech.
They’ve found a simple but striking pattern in some 500 languages spoken throughout the world. They’ve found that a language area uses fewer phonemes the farther that early humans had to travel from Africa to reach it. Some of the click-using languages of Africa have more than 100 phonemes, whereas Hawaiian, toward the far end of the human migration out of Africa, has only 13. English has about 45 phonemes. This pattern of decreasing diversity with distance, similar to the well-established decrease in genetic diversity with distance from Africa, implies that the origins of modern human language are the region of southwestern Africa.
The research is featured by the National Academy of Sciences in Ultraconserved words point to deep language ancestry across Eurasia. Professors Pagel and Atkinson looked not at words, but at phonemes – the consonants, vowels, and tones that are the simplest elements of language. They’ve come up with a list of two dozen or so “ultra-conserved words” that have survived the centuries. It includes some predictable entries: “mother,” “not,” “what,” “to hear,” “man,” etc. The existence of the long-lived words suggests that there was a “proto-Eurasiatic” language that was a common ancestor to about 700 contemporary languages that are the native tongues of more than half the world’s people. Wow!
Tom Thompson writes frequently on foreign language topics. He lives in Washington, D.C.