The shape of your nose isn't just for aesthetic purposes. It also has important functions for health and can give you an idea about your ancestry particularly where your ancestors lived.
Besides being associated with the sense of smell, the nose also serves another important function that can help prevent illness and damages to the lungs and airways. It warms and humidifies the air that a person breathes.
Because of this particular function, scientists have long thought that the shape of the nose may have partly evolved in response to climate conditions.
Regional Climates And Nose Shapes
In a new study, which was published in journal PLOS Genetics on Thursday, researchers were able to confirm this theory as they found evidence that links the shape of the nose that we have now with the climates of the regions where our ancestors lived.
For their study, the researchers involved participants whose parents and ancestors were born in regions namely West Africa, East Asia, South Asia, and Northern Europe that corresponded to their genetic ancestry. At least 40 participants were recruited for each of these regions.
The researchers found that the participants whose ancestors came from regions with warm and humid climates tended to have wider nostrils. Those whose ancestors were from cold and dry climates, on the other hand, were likely to have narrower nose with the strongest correlation observed in those whose ancestors were from Northern Europe — suggesting that cold and dry climates may have played a part in shaping narrower nostrils.
The findings back up the idea of U.S. Army physician Charles Edward Woodruff who served in the American Civil War and the Spanish-American War, which he wrote in his book The Effects of Tropical Light on White Men.
"In the tropics where the air is hot and therefore rarefied, more of it is necessary and it is essential that there should be no impediment to the air currents so the nostrils are open and wide and the nose very flat. Such a nose is unsuited for cold countries as it permits masses of cold air to flood the air passages and irritate the lining membrane," Woodruff wrote.
Study researcher Arslan Zaidi, from the Pennsylvania State University, explained that physical traits that are directly in contact with the environment are more likely to undergo natural selection and evolve faster,
"People are more similar than they are different. What this research does is offer people a view of why we're different," Zaidi said. "There's an evolutionary history to it that, I think, kind of demystifies the concept of race."
Researchers said that studying how traits that evolved as an environmental adaptation that may no longer be relevant may help with a better understanding of disease risks for certain individuals.
"The investigation of nose shape evolution with respect to climate adaptation, while interesting anthropologically, is also relevant medically. As humans are becoming more of a global community, the study of local adaptation is becoming more important to understanding health risks involved in living in 'foreign' climates," researchers wrote in their study.