Recent evidence from several studies in paleoanthropology has upended these assumptions by suggesting the way we eat can actually alter jaw anatomy. the consequences for the way we speak have been profound. Damián Blasi and Steven Moran of the University of Zurich led the research. The form of the human jaw had changed in our species’s relatively recent evolutionary past.
Among hunter–gatherers of the Paleolithic period, adults’ upper and lower teeth aligned to form a flat line, the top ones resting directly on the bottom set. Scientists attribute that configuration primarily to tooth wear brought about by chewing hard foods, such as unmilled grains or seeds. With the advent of agriculture in the post-Neolithic period, however, the upper teeth protruded over and above the lower teeth, presumably due to the reduced challenge of consuming soft foods such as porridge and cheese.
These findings suggest not only that the cultural shift that gave rise to agriculture occasioned a shift in human anatomy. It also appears to have introduced new speech sounds known as labiodentals—the “f” and “v,” for instance.
adopting the signature foodstuffs of sedentary society ultimately allowed us to mouth words like “farro” and “verbalize” by raising the lower lip and bringing it into contact with the upper teeth. Their study results showed, compared with the protruding bites, the flat bite configurations required substantially more effort to produce a labiodental.
Linguists had already established that articulatory effort can affect the fate of a phoneme, so Blasi and Moran’s team speculated that labiodentals would have been less likely to emerge among any population with flat bites, such as Paleolithic humans, or even modern humans who eat harder foods. To test this hypothesis, they analyzed databases of the world’s consonants and showed contemporary hunter–gatherer languages contain only a fraction of the labiodental sounds that food-producer languages do. Of course, food preparation techniques are merely a stand-in for actual bite configurations. To make the link more explicit, the researchers separately analyzed hunter–gatherer societies in Greenland, southern Africa and Australia, where flat bites have been explicitly documented. In line with their hypothesis, results turned up relatively few languages with labiodentals among these populations. When one of these sounds appeared, it was usually borrowed from other languages.
As a final piece of support for their argument, Blasi and Moran’s team examined sound changes in Indo-European languages over time. They used a nontraditional technique called stochastic character mapping, which calculates the numerical probability a sound existed in a language at a particular point in time. Results showed labiodental sounds were extremely unlikely in almost all branches of Indo-European, until anytime from 6,000 to 4,000 years ago. After that period, which coincides with the introduction of soft foods, the probability of these sounds showed a notable increase.
— source scientificamerican.com | Mar 14, 2019