Human diet led to speech sounds such as 'f' and 'v'

A new study suggests that developments in human speech, like the ability to make the "f" and "v" sounds, were preceded by diet-induced dental changes.

Back in the twentieth century linguist Charles Hockett first spotted that speech sounds called labiodentals, such as "f" and "v", were more common in the languages where people ate softer foods. Now a team from the University of Zurich has demonstrated how and why this happened.

They found that in ancient humans the upper and lower incisors of ancient adults were aligned, making it hard to produce the sounds, which are formed by touching the lower lip to the upper teeth. However, as jaw formations developed over the centuries a point was reached where an overbite structure was present, making it easier to produce the "f" and "v" sounds.

This change was shown to correlate with the development of agriculture in the Neolithic period. In this era softer, farmed foods, allowed the jawbone to change as it no longer had to do as much work.

Language databases confirmed the global change with the labiodental sounds not found in the languages of many hunter-gatherer societies of the present day.

This research contradicts the prevailing view that all human speech sounds were present when homo sapiens first evolved around 300,000 years ago.

"The set of speech sounds we use has not necessarily remained stable since the emergence of our species, but rather the immense diversity of speech sounds that we find today is the product of a complex interplay of factors involving biological change and cultural evolution," said University of Zurich team member Steven Moran.