About 15 to 20 thousand years ago, when human society changed from a hunter-gatherer society to an agricultural society, not only did its culture and social behavior change, but also some new sounds came out of the human language, which made it easier for humans to pronounce different words.

Ever since our ancient ancestors started consuming soft, fire-cooked food, the use of sounds like "f, f" and "waw, wa, w or v" increased in our ancient language or speech, due to the soft food itself and the ability to pronounce 'f' and 'v'.

When ancient humans turned to soft prepared foods after the spread of agriculture in the world, they used to put less pressure on their teeth, due to which their teeth were less prone to breakage. This dietary change altered the development of their jaws, leading to a new habit of chewing less food than adults, and the shape and size of our back teeth began to change. Within a few thousand years, these slight overbites made it easier for people in farming cultures to produce sounds like "f" (Urdu: ف) and "v" (Urdu: واو), opening up a world of new words, and new words began to join our ancient sounds.

These newfound consonants, called labiodentals, helped promote the diversification of languages ​​in Europe and Asia by at least 4,000 years ago. According to Balthasar Bickel, a linguist and senior author at the University of Zurich in Switzerland, they led to changes such as the change of the Proto-Indo-European word patēr (potter) to the Old English “faeder” about 1,500 years ago. Professor Bickel’s paper suggests that “this cultural change can change our linguistic biology in a way that affects our language,” says Noreen Von Cramon-Taubadel, an evolutionary morphologist at the University at Buffalo, part of the State University of New York system, who was not part of the study.

To arrive at this conclusion, the scientists first used computer modeling to show that by biting more teeth together while speaking, it takes 29 percent less effort to produce labiodentals than by biting one tooth edge at a time. Then, they surveyed the world's languages ​​and found that the languages ​​of ancient hunter-gatherers had only about a quarter as many labiodentals as the languages ​​of agricultural societies. Finally, they looked at the relationships between different ancient languages, and this computer model showed that labiodentals may have spread and been used rapidly in a language at a time when the use of soft foods through agriculture increased with the widespread adoption of agriculture and new methods of food processing, such as grinding grains into flour, about 8,000 years ago. Since then, such sounds (i.e., the f and v sounds) may have gone from rare to common.

As more mature humans developed overbites with the help of their teeth, they began to mistakenly use the "f" and "v" sounds more in their speech, says Bekel. They say that in ancient India and ancient Rome, in colloquial speech, labiodentals may have been a sign of social status, indicating a moderate diet and wealth. These pronunciations also spread to other language groups. And these pronunciations appear today in 76% of Indo-European languages, and all Indo-Aryan languages ​​have sounds like f and v.

But in opposition to this theory, these things are said

Some linguists, however, say that not the nutritional aspect or just human biology but cultural evolution caused these phonetic changes, and humans began to produce sounds like f and v.

Even today, not all languages ​​of human populations in different regions use the "f" and "v" sounds, although they also use agricultural products and soft foods.

This theory seems to be a valuable one, but it has not been universally accepted by all scientists, anthropologists and linguists.