New research led by a University College London has found out genes which determine the shape of a person’s facial profile.
The team found about 32 gene regions that influence facial features like nose, lip, jaw, etc. Nine of these were entirely new discoveries.
The team found that one gene appears to have been inherited from the Denisovans, an extinct group of ancient humans who lived tens of thousands of years ago.
They also found a gene, TBX15, which contributes to lip shape was also linked with genetic data found in Denisovan people. The Denisovans lived in Central Asia, and few suggest they interbred with modern humans and have some of their DNA in Pacific Islanders and Indigenous people of the Americas.
Dr Kaustubh Adhikari, the Co-corresponding author, said that the face shape genes they found could have been a product of evolution as ancient humans evolved to adapt to their environments. This version of the gene determining the lip shape could possibly be present in Denisovans and help them be better suited to the cold climates of Central Asia. This could have been passed on to modern humans when the groups interbred.
Dr Pierre Faux, the Co-first author, added that this was the first time that a version of the gene was inherited from ancient humans was associated with a facial feature in modern humans. It was only possible because the team moved their study beyond Eurocentric research; modern-day Europeans do not carry any DNA from the Denisovans, but Native Americans do.
The team added that the study was one of its kind in studying the genes affecting the face in a non-European population.
They could analyze complex genetic data from thousands of people at once over the last two decades, since the mapping of the human genome enabled the use of genome-wide association studies to find correlations between traits and genes, and the first one to focus on the profile only.
One of the newly discovered genes found in this study is VPS13B, which influenced nose pointiness; the researchers also found that this gene affects nose structure in mice, showing a broadly shared genetic basis among distantly related mammal species. The study compared genetic information from participants taking in consideration the characteristics of their face shape, quantified with 59 measurements (distances, angles and ratios between set points) from photos of the participants’ faces in profile.
Researches like these help us get a basic insight on how humans evolved.
These findings are helpful in understanding the developmental processes that determine facial features.
The results also contribute to the understanding of the evolution of facial appearance in human and other species.
Journal Reference:
A GWAS in Latin Americans identifies novel face shape loci, implicating VPS13B and a Denisovan introgressed region in facial variation. Science Advances, 2021; 7 (6): eabc6160 DOI: 10.1126/sciadv.abc6160
