The science explains why our nose is flat, the western tip is high

In the late 1800s, British anthropologist and anthropologist Arthur Thomson asserted that people of ancestral descent living in cold, arid climates often had thinner and longer noses, while People from warm, humid climates have shorter and thicker noses.

He proposed the theory that climate has a more profound effect on human nose shape than any other evolutionary factor, because the important task of the nose is to warm and moisten the inhaled air through the hole. nose. This helps explain why people in colder climates will have narrower nostrils and vice versa.

For years, scientists have been experimenting with Thomson's Law of the Nose on simulated skulls, but no one has ever done this study in living humans.

Researchers at the University of Pennsylvania (USA) are the first to do so. The results, published in March 2017 in the journal PLOS Genetic, confirm that Thomson was right. The researchers concluded that the size and shape of the nose evolved, at least in part, to adapt to local climatic conditions.

Arslan Zaidi, a postdoctoral graduate student in biology and lead author of the study, said: "We often ask questions like: Why do we look different? Why do men and women look Why are people living in different populations different? We have focused on the nose because many studies on the human body show that it can evolve to adapt to the climate. " .

The East Asian nose is low to adapt to the climate.

The researchers scrutinized the parameters of the nose. They examined the width of the nostrils, the distance between the two nostrils, the height of the nose, the length of the nasal bridge, the protrusion of the nose, the area outside the nose and the nostril using a three-dimensional technique. The researchers also focused on studying four different ancestral groups, including South Asia, East Asia, West Africa and Northern Europe.

Two questions the researchers ask: Is it true that some of the nose shape characteristics change with population rather than genetic variation? (Transmission variability is a random evolution process that leads to differences between populations over long periods, at random.) If so, can these changes be explained by climate?

Natural selection is likely to play an important role in human nose evolution.

Zaidi said: "In other words, we still predict that if isolates two populations over a long period of time, their noses randomly will look different by genetic fluctuations. We need the except for this to show that the difference between human populations depends on many other factors.In the seven measurements that describe the shape of the nose, we found two measurements related to the width of the nose. the difference between populations is not merely due to genetic fluctuations. This means that the difference in nose width between human populations is not just random. "

The researchers found a positive correlation between nostril width and temperature and humidity, suggesting that natural selection is likely to play an important role in human nose evolution. Natural selection is the process by which organisms adapt well to the environment that often survive and pass on the traits to the next generation, while organisms that are not adaptable often die.

People are always moving everywhere. Nowadays, it is not uncommon for a person in a cold climate to move to the equator. They may "challenge" the narrow nostrils of their ancestors.

Zaidi added: "Evolution takes a long time. If the shape of the nose evolved in the past to adapt to the local climate, it would take 10,000 years. I may still have wide noses, because I'm Pakistani, even if they live in colder climates, as long as they marry another South Asian. "

"Human differences are not identical with the concept of race. There are more similarities between people from different populations than differences, both in genetics and phenotype. such as skin pigmentation and nose width are more different because they are typical for the habit of being exposed to the environment and evolving faster than other human characteristics.This is an exception, not in the law. ", Zaidi added.

In addition to the climate, there are several other factors that influence the shape of the nose.

The researchers also noted that other factors may also be involved, such as gender differences. Men are usually taller than women, so their noses are also often bigger. Other features also play a part here because people may prefer a partner with a smaller or larger nose. However, according to scientists, the concept of beauty may be related to how well the nose adapts to the local climate.

As for the nose, Zaidi said that evolution is an extremely random process, making it difficult to predict what will happen to the human nose to cope with global warming.

Zaidi said: "Human evolution, at the moment, is very different from the past evolution. Our way of life is not like what our ancestors did, we move everywhere. in the world. That makes predicting the future evolutionary trajectory of the nose to adapt to climate change extremely complicated. "