Noses come in all different sizes and shapes, and new research has determined the genetic reasons behind the amazing variety, according to discovery.com.
Researchers analyzed almost 6,000 individuals from the nations of Colombia, Peru, Brazil, Chile and Mexico, who had been a part of the CANDELA study, a study that looked at the diversity of the Latin American population. This population has a mix of Caucasian, African and Native American ancestries and from that mix comes a wide range of prominent facial features.
The team not only looked at the study subjects, but completed 3D reconstructions of 3,000 of them in an effort to get exact measurements of the their facial features. Of course, the next step was to identify genes that were known to impact bone and cartilage growth, but also seemed to be a predictor of the shape of the nose.
The findings revealed that two genes, labeled GLI3 and PAX1, appeared to have a significant effect of the width of the nostrils, while a third gene, DCH2, factored in whether or not the nose has a pointed or rounded shape. Finally, a gene called RUNX2 was found to be associated with the breadth of the bridge of the nose.
Interestingly, three of the genes apparently have undergone changes during the relatively recent past of modern humans when compared with the genetics of older humans, including Neanderthals and Denisovans. The researchers say this seems to suggest that more recent humans have been subjected to natural selection more so that earlier humans.
It also appears that the nose has evolved into different shapes for environmental reasons as well, said the authors of the study, which was published in the journal Nature Communications.
“For example, the comparatively narrower nose of Europeans has been proposed to represent an adaptation to a cold, dry climate,” offered Andrés Ruiz-Linares, a biologist at University College London, and who is the lead author on the study. “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.”
The researchers added the new findings were important to the understanding of the evolutionary path to modern humans, and helped us closer understand how genetics may influence our appearances.