70,000 years ago (give or take a few tens of thousands of years), something happened to human beings. We started wearing clothing (to judge from the emergence of body lice) and started doing art and making much more sophisticated tools (to judge from the stuff we tossed to the floor of our cozy cave homes). And we started talking to each other. Many experts argue that this creative growth spurt was enabled by the emergence of complex language, which made abstract thought possible. But while the effect of language seems evident, evidence of the spoken word leaves no bones for bone diggers to dig up.
No one speaks this first language anymore, since over the last 2000 generations thousands of different languages have emerged from this hypothetical ancestral tongue. Evolutionary pressures have morphed into a mosaic of thousands of divergent languages, the situation of the present world, argues Nicholas Wade in Before the Dawn (highly recommended).
“Most linguists use changes in words or grammatical structures to try to track language evolution. The English word ‘brother,’ for example, translates as bhrater in Sanskrit, brathir in Old Irish, frater in Latin, and phrater in Greek. These differences can be used to reconstruct the ancient words that gave rise to these modern ones. But unlike genes, these cultural units cannot be traced back far enough to distinguish patterns of language change much earlier than about 6500 years ago.” So no proof.
Now Quentin Atkinson, an evolutionary psychologist at the University of Auckland, may have found the smoking gun in the different sounds we humans use to speak in different tongues.
As recently reported by Gautam Naik in the WSJ, Atkinson’s “research is based on phonemes, distinct units of sound such as vowels, consonants and tones, and an idea borrowed from population genetics known as ‘the founder effect.’ That principle holds that when a very small number of individuals break off from a larger population, there is a gradual loss of genetic variation and complexity in the breakaway group.”
“Dr. Atkinson figured that if a similar founder effect could be discerned in phonemes, it would support the idea that modern verbal communication originated on that continent and only then expanded elsewhere.
“In an analysis of 504 world languages, Dr. Atkinson found that, on average, dialects with the most phonemes are spoken in Africa, while those with the fewest phonemes are spoken in South America and on tropical islands in the Pacific.
“The study also found that the pattern of phoneme usage globally mirrors the pattern of human genetic diversity, which also declined as modern humans set up colonies elsewhere. Today, areas such as sub-Saharan Africa that have hosted human life for millennia still use far more phonemes in their languages than more recently colonized regions do.”
Atkinson believes that the first migrants out of Africa took their single language with them, which then multiplied linguistically as these African outcasts multiplied on their own.
Language “was the catalyst that spurred the human expansion that we all are a product of,” says Atkinson.