Release date: 2016-11-18
Why do some people have sharp and narrow noses, while others have wide noses or large nostrils? The scientists scanned the genomes of about 6,000 different individuals to find the answer to this question.
In a study of facial features in humans, some of the decisive genes that regulate the shape of the human nose surfaced.
Why do some people have sharp and narrow noses, and some people have wide noses or large nostrils? The scientists scanned the genome of about 6,000 people and found four pairs of genes involved in regulating the shape of the nose and a pair of genes that affect the degree of chin protrusion.
Researchers believe that these findings will help us understand our own evolutionary history. Andrés Ruiz-Linares, professor of human genetics at the University College London, who led the study, said: "Now our main job is to try to identify these genes and use them to understand our evolutionary problems - to what extent are the evolution of these traits Adaptable, to what extent can they reflect the history of the population."
In addition, the researchers believe that this study can also help us better understand developmental defects, and even provide courtiers with more accurate facial reconstruction of suspects.
But some people are skeptical about this. The genetic variants associated with each trait have been found to account for only about 1% of the observed variation in the population, indicating that more genes are at work. Manfred Kayser, director of the Institute of Genetics and Research at Erasmus University in the Netherlands, said: “Before applying the relevant genes to predict facial features based on DNA, we first need to confirm these results in larger studies, and the results should be Repeat in the sample of relevance."
In a paper published in the journal Nature Communications, the researchers used DNA samples and photographs from 5,958 participants from Latin American countries. The author explains that this community (Latin American population) offers a great opportunity to explore the diversity of facial features as Latin Americans live with Native American, European and African descent. Ruiz-Linares. “Europeans usually have narrow, protruding noses, while Native Americans have flatter, wider noses.â€
First, they took a close look at the participants' photos and divided their faces into three grades according to 14 different characteristic attributes, including the width of the bridge of the nose, the degree of nose protrusion, and the shape of the tip of the nose. Next, they used a 3D computer model to more accurately analyze the seven facial features of about half of the participants. In both methods, scientists carefully examine the genetic information of the participants to understand the relationship between the traits to be studied and the genes.
The study found that a mutation in a gene named EDAR affects the degree of chin swelling. Interestingly, this gene affects a variety of facial features, and scientists have previously found that it can also affect the size of the earlobe, the thickness of the beard, and whether a person's hair is straight.
At the same time, there are many genes that regulate the shape of the nose. Overall, the GLI3 and PAX1 genes control the size of the nostrils, while the RUNX2 gene controls the width of the nasal bridge. The DCHS2 gene regulates the degree of protrusion of the nose, which determines whether the tip of the nose is facing upwards and the tip of the nose – or it determines whether your nose is charming and straight. Ruiz-Linares believes these findings are meaningful, he said: "As we all know, these genes are involved in the synthesis of bone and cartilage, as well as the development of the craniofacial."
One theory holds that the diversity of human nose shapes is attributable to the pressure of natural selection. Ruiz-Linares explains: “Classic theory believes that the shape of the nose must be adapted to the temperature and humidity of the air that the individual breathes, so it can be pushed out. In colder weather, the narrower nose has a more selective advantage. This narrowness The nose is typical of Europeans because it warms in the air as it breathes and increases the humidity of the inhaled gas.
Not only that, but scientists have also discovered that the three genes associated with the shape of the nose show the difference between modern people and our close relatives, the Neanderthals and the Denisova. This suggests that these genes may be involved in regulating the different appearance characteristics between us and our ancient close relatives.
Ruiz-Linares concludes: "The genetic basis of these traits can help us understand the evolutionary process from a macro perspective.
Source: Global Science Scientific American WeChat Public Number
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