一个人鼻子的形状和大小大体上由遗传决定，但基因并不是唯一缘由。最新研究指出，气候条件同样在人类鼻子外形的演变过程中发挥着要紧用途。
If you are not satisfied with the shape of your nose, blame it on climate, not your parents or grandparents.
对我们的鼻子形状不认可？不要怪爸爸妈妈或祖爸爸妈妈，怪气候吧。
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.
美国宾夕法尼亚州立大学的研究职员发现，人类鼻子的形状至少部分是由当地气候长期塑造而形成的。这项研究本周发表在美国《科学公共图书馆遗传学》杂志上。
Generally, wider noses are more common in warm and humid climates, while narrower noses are more common in cold and dry climates, it said.
大体上，温暖湿润区域的人鼻子较宽，而寒冷干燥区域的人鼻子较窄。
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.
研究职员剖析了西非、南亚、东亚、和北欧血统的人鼻子的大小与形状。
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.
借用3D面部成像技术，研究职员察看了鼻孔宽度、鼻孔间距离、鼻子高度与鼻梁长度、鼻子突出程度、鼻子外部地区、和鼻孔地区等。
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.
结果显示，鼻孔宽度与被叫做基因漂移的随机过程无关，而与温度和绝对湿度等气候特点强有关。
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.
鼻子的一个功能是调节吸入的空气，让空气在进入肺部时变得温暖、湿润，帮助预防感染。
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.
现在的研究发现，窄鼻孔可以改变气流，因此分泌有粘液的鼻腔可以更有效地湿润和温暖吸入的空气。
"It was probably more essential to have this trait in cold and dry climates," it said.
研究报告写道：“这可能对干冷气候中的大家更要紧。”
"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."
“在较寒冷的气候中，较窄鼻孔的人可能比较宽鼻孔的人过得更好一些，有更多的后代。这致使离得远远的赤道的人群鼻子渐渐变窄。”
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.
鼻子演化历史较为复杂。研究职员猜测，可能也有其他原因对鼻子的形状发挥用途，譬如对鼻子大小的择偶偏好。
Investigations into nose shape evolution and climate adaptation may have medical as well as anthropological implications.
对鼻子形状演化历史和气候适应性的研究也有医学和人类学意义。
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.
人类进化的有关研究对大家理解疾病，与深刻知道为何特定病症（譬如镰状细胞性贫血、乳糖不耐症、和皮肤癌）在某些人群中更容易见到尤为重要。
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.
研究职员表示，当大家生活在与祖先不一样的气候中时，鼻子的形状和鼻腔的大小是不是能影响一个人患上呼吸疾病的风险，这或许值得研究。
