對鼻子形狀不滿意? 這要怪氣候咯!

If you are not satisfied with the shape of your nose, blame it on climate, not your parents or grandparents.

對自己的鼻子形狀不滿意？不要怪父母或祖父母，怪氣候吧。

In a study published this week in the journal PLOS Genetics, researchers from the Pennsylvania State University found that human noses may have been shaped, at least in part, by a long process of adaptation to local climate conditions.

美國賓夕法尼亞州立大學的研究人員發現，人類鼻子的形狀至少部分是由當地氣候長期塑造而形成的。這項研究本週發表在美國《科學公共圖書館·遺傳學》雜誌上。

Generally, wider noses are more common in warm and humid climates, while narrower noses are more common in cold and dry climates, it said.

大體上，溫暖溼潤地區的人鼻子較寬，而寒冷乾燥地區的人鼻子較窄。

The findings were based on an examination of the size and shape of noses on people with West African, South Asian, East Asian, or Northern European ancestry.

研究人員分析了西非、南亞、東亞、和北歐血統的人鼻子的大小與形狀。

The researchers looked at the width of the nostrils, the distance between nostrils, the height of the nose, nose ridge length, nose protrusion, external area of the nose and the area of the nostrils by using 3D facial imaging.

藉助3D面部成像技術，研究人員觀察了鼻孔寬度、鼻孔間距離、鼻子高度與鼻樑長度、鼻子突出程度、鼻子外部區域、和鼻孔區域等。

It showed that the width of the nostrils is strongly correlated with temperature and absolute humidity, but not the result of a random process called genetic drift.

結果顯示，鼻孔寬度與被稱爲基因漂移的隨機過程無關，而與溫度和絕對溼度等氣候特徵強相關。

One purpose of the nose is to condition the air that we breathe, to ensure that it is warm and moist when it reaches the lungs, which helps to prevent infections.

鼻子的一個功能是調節吸入的空氣，讓空氣在進入肺部時變得溫暖、溼潤，幫助預防感染。

The current study found the narrower nostrils seem to alter the airflow so that the mucous-covered inside of the nose can humidify and warm the air more efficiently.

目前的研究發現，窄鼻孔可以改變氣流，因此分泌有粘液的鼻腔能夠更有效地溼潤和溫暖吸入的空氣。

"It was probably more essential to have this trait in cold and dry climates," it said.

研究報告寫道：“這可能對乾冷氣候中的人們更重要。”

"People with narrower nostrils probably fared better and had more offspring than people with wider nostrils, in colder climates. This lead to a gradual decrease in nose width in populations living far away from the equator."

“在較寒冷的氣候中，較窄鼻孔的人可能比較寬鼻孔的人過得更好一些，有更多的後代。這導致遠離赤道的人羣鼻子逐漸變窄。”

The nose has had a complex evolutionary history, however, and researchers suspected that additional factors, such as cultural preferences when picking a mate, have also played a role in shaping the nose.

鼻子演化歷史較爲複雜。研究人員猜測，可能也有其他因素對鼻子的形狀發揮作用，比如對鼻子大小的擇偶偏好。

Investigations into nose shape evolution and climate adaptation may have medical as well as anthropological implications.

對鼻子形狀演化歷史和氣候適應性的研究也有醫學和人類學意義。

Studies of human adaptation are essential to our understanding of disease and yield insights into why certain conditions, such as sickle cell anemia, lactose intolerance or skin cancer, are more common in certain populations.

人類進化的相關研究對我們理解疾病，以及深刻了解爲什麼特定病症（比如鐮狀細胞性貧血、乳糖不耐症、和皮膚癌）在某些人羣中更常見非常重要。

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

研究人員表示，當人們生活在與祖先不同的氣候中時，鼻子的形狀和鼻腔的大小是否能影響一個人患上呼吸疾病的風險，這也許值得研究。