There are five human sense: sight, hearing, touch, taste and smell. According to statistics, people in their daily lives more than 90% of the information obtained from the visual, followed by hearing, touch and taste, smell is often only on an insignificant position. Scientific research shows that the human sense of smell is indeed degraded. The nose is used for breathing and smelling organ. We must ask: human olfactory degraded, but the human nose is more prominent than apes but why do? Let's make a comparison of human and ape nose: Located in the center of Lianpan our human nose is the most prominent features of organs. Apes nose is very small, and deep in the center of the Basin. Why do people do have a big nose?
Human olfactory degradation in evolution
In the sense of the body's five, on the importance, the sense of smell is usually on the last one, but the sense of smell is one of the oldest human feeling. Many animals rely on sense of smell for survival, such as looking for food, chasing the opposite sex, and so avoid the danger. This original feeling is also useful to humans. For example, the smell of food can improve a person's if you smell burning smell, people will pay attention to if you smell a gas leak and the smell of food deterioration, people from misfortune. For humankind, smell is a primitive feeling, through continuous evolution, humans became sedentary life of the higher animals, a substantial increase in the quality of life, food security and more, without going through the sense of smell to determine if a plant is toxic, thus happen "olfactory degeneration." German scientists by comparing human primates, and some visual after concluded: With the evolutionary process, humans have a more keen but at the same time, the need for human perception of smell things around by getting smaller and smaller, the control of the human sense of smell because of mutations in genes lose half of action. This makes the human sense of smell functions shrinking.
According to another person's nose is degraded vomeronasal organ atrophy. In addition to the animal nose, there were a olfactory organ: the vomeronasal (septum bottom hose-like recess, have to accept the so-called special pheromone receptors). Due to advanced evolution in other areas, people do not need to feel the vomeronasal organ can cause escape, attack, make sure that pheromones offspring and other reactions, so the human vomeronasal organ during embryonic development to 26 weeks, they start atrophy.
Why is the human nose so "outstanding"?
In primates, only humans have a prominent nose. And close relatives of humans - great apes have no such nose: Gibbon flat nose, the eagle was orangutans small, flat nose, gorilla bridge collapse, nostrils large and have shiny, raised pleat chimpanzee nostril small and narrow. They are not as sudden as if on Yimapingchuan raised a small hill human nose.
There is a view Experts: increase in human nose is the result of human adaptation to speak. Nose outside the human nose grow, increase the length of the nasal passages, which is to extend the channel, which is good for people to pronounce speak. Nose amputated due to torture people, or lost due to illness of the nose, their voices are significantly impaired, this aspect proved the nose from a function. Nasal bone human nose than the apes is increased to enhance the nasal resonance, which greatly improved the ability of human beings to speak pronunciation.
Why do men have a larger nose?
A recent study researchers University of Iowa showed that taking into account the size of the body, on average, than men nose to nose women is 10%. Why is this? Researchers from the men and women of different muscle composition gives the answer. With age, men muscle outline more prominent, in order to ensure growth and maintain muscle contour, the greater the amount of oxygen in men. In fact, to ensure a greater nose inhale more air, which enters the bloodstream to provide more oxygen to muscle growth. For women, do not need more oxygen, so they are not so prominent nose, the nose, the right size is sufficient.
Why do people with high-latitude large nose?
Research found that low-latitude regions, human nose relatively flat wide, high latitudes, the nose high and long. Why is this? In Eurasia, people living in the tropics due to strong light, the temperature is too high, their noses wide, is to timely exchange of heat. The cold at high latitudes, the temperate, cold weather, the human nose need to look at the cold air preheating, otherwise enter the lungs will be uncomfortable, a little right amount of curvature can be preheated. In order to resist the cold, high latitudes tend to have a higher than low latitudes human nose, and more curved nose, nasal pores longer.
Various other related nose ......
1. The vomeronasal organ degeneration
Different from other mammals, the human vomeronasal organ is highly degraded. In fetuses and newborns, it is obvious that the structure of the vomeronasal organ. Newborn seems to have offspring and other mammals, like mother nipple through the dissemination of pheromones looking breasts. But as the baby grows, the vomeronasal organ gradually degraded. 564 scientists doing anatomy adults showed that 70% of people do not have a vomeronasal organ structure, the remaining 30% of the vomeronasal organ is highly degraded. Human vomeronasal organ composed by two small, two position in the deep portion of the nasal cavity, some people vomeronasal opening the naked eye to see, but most people use a magnifying glass to see.
2. The human nose can identify 2000 kinds of odor
People's sense of smell was not as most animals, but still has a certain sensitivity, can even discern 0.00004 milligrams per liter of air containing only artificial musk smell. According to expert determination, ordinary people can identify at least 2000 kinds of odor, and trained people can recognize up to 10,000 kinds of odor. Although the human smell receptors only about 1,000 species, but they can generate a lot of combinations, forming a large number of odor mode, this is the person able to identify the physiological basis of memory and different odors.
3. like to pull the nose of people smarter?
Pull the nose in public, often considered unsightly thing, but a Canadian study found that, in fact, pull the nose of the human body is beneficial. Research indicates that people who would like to pull the nose smarter than people did not dare to pull the nose. Research indicates that because the inner nose contains a variety of receptors, so when people use finger massage nasal mucosa, can stimulate the brain to produce the effect. Thus, over time, those who like to pull the nose of the people than others because of fear of not dare to pull the nose pointing people smarter.
4. Protection nose
The nose is not just a simple air out of the pipe. If the air in a really straight nose and straight out without any change, then sand, snow and rain throughout the year would have put the lungs into a trash can. The reason this does not happen, it is because the nose like an air conditioner, like a humidifier, like an air filter, like the four seasons of different temperatures and humidity, not very clean air for heating, humidifying and filtering into warm , the degree of humidity and almost sterile, so the body will not change too much by outside influence, to ensure health. Surprisingly, these functions only in the nasal airways this short period, but only in the short moment conducted.
(Author: Yang Yang)
Licensing and commercial cooperation, please contact zhidaoribao@baidu.com, Baidu know the daily chase responsibility and rights reserved.
Article Source: Baidu know daily (http://zhidao.baidu.com/daily)
Original link: http: //zhidao.baidu.com/daily/view id = 828?