As we reported recently, a new study has come to a fascinating conclusion about the shape of the human nose, showing that it’s not just about aesthetics. But why exactly has our nose evolved to fit the climate? The answer is as fascinating as it is strange.

This is actually not a terribly new idea. In 2011, scientists in Germany published research showing that cold and dry climates like in Greenland and Siberia feature people with higher and narrower nasal cavities.

They compared 100 skulls from 10 human groups in five different climates, and found that the nasal cavities of cold, dry climate populations were quite different from those in hot and humid environments.

Why is this the case? By narrowing, the nasal passage, the contact between the air and mucosal tissue increases, which warms and humidifies the air. These nasal passages are often longer as well, providing more space to bring the incoming air up to body temperature.

Microscopic hairs called cilia line the nasal passages to keep out dust and pathogens that might irritate the lungs, and the cilia needs the air to be moist.

“Few studies have looked at how normal facial features develop and those that have only looked at European populations, which show less diversity than the group we studied. What we’ve found are specific genes which influence the shape and size of individual features, which hasn’t been seen before,” the first author of the report, Dr Kaustubh Adhikari, UCL Cell & Developmental Biology, said in the statement. “Finding out the role each gene plays helps us to piece together the evolutionary path from Neanderthal to modern humans. It brings us closer to understanding how genes influence the way we look, which is important for forensics applications.”