The chin was formed due to cooking
The human body took different path of evolution than other mammals. The bigger brain in the species definitely resulted in some advance practices and different body structure of the homo sapiens. The other similar animals like chimpanzees and Gorillas to humans do not posses the chin. This has became part of the study among anthropologists.
The research is saying that the humans developed chins because of they mastered the art of cooking. The soft cooked food made less effort and time in chewing, consequently our jaws and teeth reduced in the size. The scientists have studied the structure of facial bones of other mammals and concluded that chin is only unique to humans but the reason behind it was a subject of long debate. Some alternate reasons have been told by the researchers as the chin functioned as a tool to attract a partner. So when you wonder about the popularity of the stars like Kirk Douglas, give some credits to their chins. The chin signified the sexual strength of a human being.
But the logic doesn’t fit well into evolutionary biology. In humans, both male and females have chins. As per the nature’s rule, only either one of the sexes have such organs to attract partner. There are many examples of this among the animal kingdom. The alteration of the genetic structure by some external factor is the only plausible cause here as the process has nothing to with the natural selection.
The development of cooking by humans may have resulted in less cooking time and consequently human being developed chins as teeth and jaws became smaller in size, according to the study published in Journal of Human Evolution.