Don't like your flat nose? Who can you 'blame'?

Woman poses for a photograph at the office of her surgeon in Tehran.
Woman poses for a photograph at the office of her surgeon in Tehran.PHOTO: REUTERS

Do you have a honker, a bulbous beak or a flat, flared sniffer?

The size and shape of the nose evolved, at least partly, in response to local climate conditions, according to a study by Pennsylvania State University researchers, published yesterdayin the journal PLOS Genetics.

Apart from its distinct look, the nose also has the crucial job of conditioning the air that people breathe in to ensure that it is warm and moist when it reaches the lungs, which helps to prevent infections, said PLOS.

Previous studies suggest that people whose ancestors lived in hot, humid places tend to have wider nostrils than those who originated in cold and dry environments. But it was not known if these differences arose in response to local climates or just due to chance.

In the latest study, researchers examined the size and shape of noses on people with West African, South Asian, East Asian, or Northern European ancestry, and found that differences in nose shape across these populations are greater than can be explained by chance alone.

Also, wider nostrils are correlated with ancestors who evolved in warmer temperatures and with greater absolute humidity, suggesting that climate was one factor driving nasal evolution.

The researchers suspect that additional factors, such as cultural preferences when picking a mate, have also played a role.

Investigations into nose shape evolution and climate adaptation may have medical and anthropological implications, the journal said.

Studies of human adaptation are essential to understanding disease and shed light on why some conditions are more common in certain populations.

The researchers said it may be worth looking at whether nose shape and size of the nasal cavity impact the risk of contracting a respiratory disease when living in a climate that is different from a person's ancestors.

A version of this article appeared in the print edition of The Straits Times on March 17, 2017, with the headline 'Don't like your flat nose? Who can you 'blame'?'. Print Edition | Subscribe