How Humidity Influenced the Evolution of the Human Nose

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While our noses are handy for sniffing out the difference between, say, a blooming corpse flower and a cedar tree, they also play an often overlooked role: air conditioner.

As we inhale, our noses heat and condition the air, prepping it for the exchange of oxygen and carbon dioxide in the lungs. If the air is too dry, the nose helps humidify it. The process also keeps respiratory tissues from drying out, which can stave off the development of infections.

Previous research has suggested that because people need to regulate the temperature and humidity of the air entering their bodies, noses have evolved different shapes in warmer and cooler climates. Now, a new study is refining how climate helps explain how your nose got its shape.

The research, which was published in June in the American Journal of Physical Anthropology, may lead to a better understanding of the evolution of the human face and why facial features vary among different ethnicities.

"It's an important study that lays out the potential climatic variables we should be focusing on," said Nathan Holton, a biological anthropologist at the University of Iowa in Iowa City who wasn't involved in the research. [...] laboratoryequipment.com / Link 2