Scientists sniff out genes which help to shape your nose
Four genes help determine whether you are blessed with the neatest of noses or a schnozzle that would shame Cyrano de Bergerac, research has shown.
Scientists analysed the DNA of more than 6,000 people to discover why some of us possess narrow, pointy noses while others have hooters that are broad and hefty.
They identified four genes that affect the width and pointiness of the nose, known as DCHS2, RUNX2, GLI3, and PAX1.
A fifth gene, EDAR, was found to influence the jut of the chin.
The genes are among those that regulate the growth of bone and cartilage, and the shape of the face.
GLI3, which drives cartilage growth, had the strongest effect on the breadth of the nostrils. DCHS2 was linked to pointiness, while the bone-growth gene RUNX2 modified nose bridge width.
Senior researcher Dr Kaustubh Adhikari, from University College London, said: "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.
"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."
All the study participants came from South American countries with mixed ethnic populations. Half the population had European, 45% Native American and 5% African ancestry.
Photos of the volunteers were first examined to establish 14 different attributes, including nose bridge width, nose protrusion and the shape of the nose tip. Facial features were also measured using 3D computer simulations.
Genetic data was compared with each characteristic trait to see if there was an association.
The findings are reported in the journal Nature Communications.
Study leader Professor Andres Ruiz-Linares, also from University College London, said: "It has long been speculated that the shape of the nose reflects the environment in which humans evolved.
"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.
"It may also help us understand what goes wrong in genetic disorders involving facial abnormalities."
:: Cyrano de Bergerac, a 19th century play written by Edmond Rostand, depicts the life of a dashing French duellist and poet whose shockingly large nose stands between him and the woman he loves.