The shape of one’s nose can carry a lot of weight — it can be everything from a source of poor self-esteem to a proud reminder of one’s ancestry. It may not seem relevant to your health today, but the shape of certain facial features has a basis in evolution and formed to provide one advantage or another. Now, scientists have identified the exact genes that drive the shape of one’s nose, adding to how we understand the development of human facial structures.

The study included a population of more than 6,000 people with varying ancestry all over Latin America, and allowed researchers to identify four genes that affect the width and pointiness of the nose, and one that affects chin protrusion. Both men and women were involved in the study, undergoing full genome analysis to reveal the genes responsible for their appearance. Researchers even assessed the features of a subgroup of participants using 3-D reconstruction to obtain exact measurements of facial structures.

“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,” said Dr. Kaustubh Adhikari, a University College London professor and first author of the study, in a press release. “What we’ve found are specific genes which influence the shape and size of individual features, which hasn’t been seen before.”

The findings have modern forensic applications — knowing how genes influence the way we look can help experts create facial reconstructions — but mostly they provide another piece in the evolutionary puzzle. Adhikari said that understanding the role of individual genes helps researchers create a complete timeline from the time of the Neanderthals to the present day. Scientists have theorized that nose shape is important for regulating humidity and temperature of the air that enters our body, with different shaped noses becoming advantageous for warmer or cooler climates.

“It has long been speculated that the shape of the nose reflects the environment in which humans evolved,” explained Professor Andrew Ruiz-Linares of the University of College London Biosciences, who led the study. “For example, the comparatively narrower nose of Europeans has been proposed to represent an adaptation to a cold, dry climate. Identifying genes affecting nose shape provides us with new tools to examine this question, as well as the evolution of the face in other species.”

Ruiz-Linares also noted that the findings could help explain what goes awry in genetic disorders that result in facial abnormalities.

Source: Adhikari K, et al. A Genome-wide Association Scan Implicates DHS2, RUNX2, GLI3, PAX1 and EDAR in Human Facial Variation. Nature Communications. 2016.