If ancestral climates shaped your nose, could they have shaped other parts of you, including your brain? That’s only logical.
Ask anyone what the nose does, and the reply will most likely be related to smell. We appreciate our noses because they help us experience flowers and fresh-baked cookies.
In fact, our honkers have another, more important function: They warm and humidify the air we breathe, helping prevent illness and damage in our airways and lungs. Because of this, scientists have long suspected that nose shape evolved partly in response to local climate conditions. In cold, dry climates, natural selection may have favored noses that were better at heating and moisturizing air.
A team led by scientists at Pennsylvania State University has found more evidence of the relationship between the noses we have now and the climates where our ancestors lived.
In a study published in PLOS Genetics on Thursday, the researchers found that nostril width differed significantly between populations from different regions around the world. Moreover, the higher the temperature and absolute humidity of the region, the wider the nostril, the researchers found, suggesting that climate very well may have played a part in shaping our sniffers.
Physical traits that are in direct contact with the environment often undergo natural selection and evolve faster, said Arslan Zaidi, a postdoctoral scholar in genetics at Penn State and an author of the paper. “This is one of the reasons why we looked at nose shape.”
…Between the groups in this study, only nostril width and skin pigmentation showed greater differences than would be expected because of chance accumulations of genetic mutations.
Over all, people whose parents and ancestors came from warm, humid climates tended to have wider nostrils, whereas those from cold, dry climates tended to have narrower ones. Correlations between nostril width and climate were strongest for Northern Europeans, the researchers found, suggesting that cold, dry climates in particular may have favored people with narrower nostrils…
Studying how certain traits evolved as environmental adaptations that may no longer be relevant could also help us understand disease risk today, Dr. Zaidi said.
“We know there are variable risks of respiratory diseases across different populations in the U.S.,” he said. “Can we find an explanation for that in morphology?”
