The ability of humans to talk may have been influenced by how early people were able to master the art of cooking and chewing their food, a new study says.
Evolutionary biologists Daniel Lieberman and Katherine Zink from Harvard University examined how early techniques in preparing and even consuming food helped our ancestors developed smaller jaws and teeth that were more finely tuned for speaking.
In their study featured in the journal Nature, the researchers pointed out that ancient hominins were able to spend less time and energy chewing their food after they picked up skills in slicing and chopping raw meat into smaller portions.
The Homo erectus, which is considered to be the closest ancestor of modern man, evolved to have relatively larger brains compared to other early humans such as the Australopithecus afarensis. This meant that they needed to expend more energy in order to grow.
However, an analysis of the Homo erectus' anatomy shows that this ancient man had smaller teeth, weaker muscles for chewing and even a smaller stomach, which made it less equipped to obtain enough energy from its diet.
The Homo erectus would have benefitted from being able to cook food as it would allow them to consume meat readily. However, the concept of cooking only became widespread some 500,000 years ago.
Lieberman and Zink found the key to this early man's survival in its ability to prepare its food before eating them. The researchers' findings show that slicing raw meat and pounding vegetables allow the Homo erectus to chew its food 26 percent less forcefully and 17 percent less often than it would have if it didn't prepare its food well.
Processing food, even through the use of crude materials such as a piece of carved stone, lessened the evolutionary pressure on the Homo erectus to have sharper teeth and stronger jaws than its predecessors.
By chewing smaller pieces of meat, the Homo erectus was able to develop a facial and dental structure that was more applicable for other functions, such as locomotion, thermoregulation and speech production. It may have led to the change in shape and size of this early man's brain.
Photo: Ryan Somma | Flickr