It has been recently reported by researchers that the reason humans have formed a chin is because our skulls are shrinking.
The theory before this report was the chin was made by evolution to assist humans in the chewing process.
In a study by a group of researchers from the University of Iowa lead by Nathan Holton, the observations in the development of the bones in the face were looked at.
There were 37 test subjects that spanned the years of growth of their faces from 3 to early adulthood.
The concentration of the study was to observe just how the bones developed over time due to the different stress load each subject placed on them.
In total there were over 292 different measurements in this study to deduct their findings. What was observed in the study was that in time as each subject aged, their chin would grow and become more prominent.
What was unusually is that the greatest level of stress placed on the jaw and chin area was done on the subjects when they were young.
This goes counter to the theory that the development of the chin was primarily for the purposes of supporting the chewing process.
The new theory now being introduced is that the chin on humans is not really growing but the other parts of the skull are shrinking.
Just like the nasal passages in humans are getting smaller, because there is no need for them to be larger since humans are now rarely hunter-gathers since they have become domesticated.
The need for large qualities of air instantly is not essential to life.
The prominent chin is just a left over from what was needed in the past. Will it ever disappear like in the Neanderthals, only time will tell.
via Science - Google News http://ift.tt/1zjOOOe
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