Photos from open sources
The authors of a new study believe that the acquisition pointed chin mankind can thank evolution.
A pointy chin
Compared with other relatives of people, for example, with Neanderthals, modern Homo sapiens have pronounced chins. Nathan Holton, an anthropologist at Iowa State University, like many other specialists, suggested that the chin modern man helps his jaw to chew movement.
However, in the course of the study, the anthropologist discovered that this theory does not stand up to criticism. It turns out chin development is not has nothing to do with the resistance of the jaw to bending stresses. Moreover, they are not even related.
According to Holton, a pronounced chin may be just a side effect of the evolutionary changes of our faces.
To determine if the chin is protected when the jaw is bent chewing time, Holton and colleagues studied x-rays people whose age ranged from 3 to 60 years. To to track the development of the jaw, as well as the distribution of bone tissue, associated with protection against various types of stresses, scientists also carefully studied x-rays of the skulls of Neanderthals.
Human chin shape
In the images of the skulls of modern people, a point is clearly visible, indicating chin, while neanderthal skulls do not show such a feature of the structure. Also chins modern people become more pronounced with age. However scientists have not found any consistent links between development chin and chewing loads of the jaw. In fact, the jaws of children under three years of age can withstand loads much better than jaws of an adult, and this despite the fact that children’s chins are not well developed.
If the chin does not provide jaw protection, what is the reason its development?
In general, the genus Homo (which includes humans, Neanderthals and our other ancestors) over time experienced an evolution in side of decreasing face. However the lower jaw that stopped increase in the distant past, today it’s becoming more expressed in comparison with other proportions of our reduced the evolution of individuals.
This begs the following question: why did our faces shrink? Holton admits that hormonal changes related to reducing violence and expanding collaboration between people. In other words, people stopped be in constant stress, therefore their hormonal background, which in turn affected external changes. People’s life not only calmer, but also easier and as a side effect decreased the total size of not only the bodies of our ancestors, but also their faces.
Time Evolution
