In the futuristic movie “Gattaca,” those in the ruling class are genetically engineered to be a physically perfect version of their parents. They are as thin and tall as models, with perfect cheekbones, square jaws and thick, glossy hair. Think of stars Uma Thurman and Jude Law. When the movie came out in 1997, this idea of “designer babies” was still far-fetched. DNA analysis was still in its early stages and the world was still years away from sequencing the first human genome, much less a particular gene’s function.
But in the more than 20 years that have passed, our understanding of our own DNA and how it works has exploded, and scientists have discovered a great number of genes that control our physical appearance. We now know that most blue eyes come from changes in a gene known as HERC2 that occurred during the Stone Age, that the classic Irish combination of red hair and a fair face comes from MC1R and that thick Asian hair appears to originate from EDAR. There are at least eight genes that appear to be associated with skin color, more than 20 impacting height and a number affecting weight.
This week, scientists writing in Nature Communications reported that they had found five new genes that impact that one feature on our faces that practically everyone thinks can be improved: noses.
The analysis involves scans of facial features of 6,000 volunteers in Latin America. According to DNA analysis, the group was estimated to be 50 percent European, 45 percent Native American and 5 percent African. Researchers measured nose-bridge breadth (the width in the middle of your nose), nose-wing breadth (the width at the bottom of your nose where it widens) and columella inclination (the incline of that section between the two nostrils), and found that they were associated with genes known as DCHS2, RUNX2, GLI3, PAX1 and EDAR.
The study also found that these genes appear to influence other facial characteristics such as your forehead profile, the thickness of your lips and how much your brow ride protrudes.
Understanding our facial traits is important for a lot of things beyond our own vanity and our hopes for our kids.
Kaustubh Adhikari and co-authors said this work has important implications for understanding human evolution, for instance.
“Physical anthropologists [have] long used this variation to examine human population diversification, including the possibility that these features have been influenced by adaptation to the environment. It has also been proposed that the diversity of human faces could have evolved partly to facilitate individual recognition, a key aspect of social interaction,” they wrote.