You probably think you inherited the shape of your nose from your parents. There is no doubt that people’s physical features are influenced by hereditary factors, but according to a new scientific study, climate is also factor that plays a role. The study, carried out by researchers from Ireland, Belgium and the US found that people’s nose shapes developed differently in different parts of the world. Researchers say their findings back up the theory that wider nostrils developed in populations living in warm, humid conditions, while populations living in high latitudes, such as northern Europe, developed narrower nostrils as an adaptation to the chilly, dry conditions. “People have thought for a long time the difference in nose shape among humans across the world may have arisen as a result of natural selection because of climate,” said Arslan Zaidi, co-author of the study from Pennsylvania State University. But while previous studies were based on measurements from human skulls, he says, the new study looked at nose shape itself. The results revealed that only two out of seven nose-related traits were found to differ more between the populations than would be expected from the impact of random, chance changes in genetic makeup over time. The authors say that suggests variations in those traits have been influenced by natural selection. The results showed that nostril width is linked to temperature and absolute humidity, with participants whose ancestors lived in warm-humid climates on average having wider nostrils than those whose ancestors lived in cool-dry climates.