Associate Professor Takeshi Nishimura of the Primate Research Institute of Kyoto University and others predict that "nose height," which is one of the differences between the original and the monkey, has been adapted to the temperature and humidity adjustment functions. I was conducting research.However, as a result of the investigation, it became clear that the ability of human nose to regulate temperature and humidity is considerably inferior to that of chimpanzees.It means that the original man, who has evolved differently from the early human being, the monkey man, deteriorated the nasal function in the process.
"Australopithecine" was separated from apes such as chimpanzees, and then "original" appeared in Africa.Several species of monkeys at that time will be extinct due to severe climate change, but only the original lineage will survive, leading to us humans with flat faces and protruding noses.
The nose has the role of adjusting the temperature and humidity of the inhaled outside air.This prevents cold air from entering the lungs, damaging organs and causing functional deterioration.Since the original man had a different "protruding nose" than the monkey man, he hypothesized that he was able to survive in severe climate change because of some functional advantage in the shape of his nose.
Therefore, the research group created a digital model of the nasal cavity of a human as an original model and a chimpanzee as a monkey model, and simulated it at the Japan Advanced Institute of Science and Technology.As a result, it was found that the human nasal cavity is inferior in temperature and humidity control function to the chimpanzee, and the protruding nose is almost useless.
It is also predicted that the reason why the original man survived despite the inferior nasal function of the monkey man was that he could adjust with the long pharynx that developed at the same time as the flat face.The long pharynx leads to the original person acquiring a spoken language.It is believed that the evolution of the nasal cavity and pharynx complementing each other allowed the original man to survive the climatically volatile Pleistocene and enter Eurasia, where the climate is even more severe.
Based on this result, it is expected that the process of evolution and adaptation of nasal morphology in monkeys that have advanced into various environments will be clarified, and that further new views will be given to the evolution of human morphology.
