An article published in the journal “Science Advances” reports a genetic study on Native Americans of South America concerning the identification of a number of their genetic regions that influenced their facial features. Some of them were inherited from the Denisovans, another human species now extinct. A team of researchers used genetic data from 6,192 Latin American volunteers involved in a large study by the CANDELA (Consortium for the Analysis of the Diversity and Evolution of Latin America) consortium to identify genes inherited from the Denisovans. This will help investigate the ancestry of Native Americans in Asia, where the only traces of this species have been found.
The CANDELA consortium is multidisciplinary, so it goes far beyond genetic studies. It includes researchers who study the diversity of the inhabitants of South America at the biological level but also their social context. The volunteers who are participating in this large study live in Mexico, Colombia, Peru, Chile and Brazil. Examination of the volunteers includes careful measurement of their facial features, as can be seen in the upper part of the image (Courtesy Bonfante et al.), where they’re shown together with associated genes, shown in the lower part.
The wealth of information gathered on the volunteers allowed 32 facial traits to be associated with a range of genes, increasing the number of genes for which there is a well-supported knowledge of their expression. A very interesting discovery is that some of the genes found in Latin American volunteers are also present in the Denisova genetic database. The DNA of these now extinct hominins is available thanks to the fact that the few bones attributed to them were discovered in Siberia, where they got preserved very well, to the point of allowing genome fragments of the individuals buried in the cave where they were discovered for the first time to be sequenced.
Dr Pierre Faux of the Aix-Marseille University, France, commented that it’s the first time that a gene inherited from ancient humans has been associated with facial features of modern humans. This was possible because this research is about Native Americans and not Europeans, who typically have Neanderthal genes.
Genes inherited from the Denisovans are typical of various Asian populations following interbreedings between modern humans and this now extinct human species. This feature could help reconstruct the history of migrations that brought some ancient populations to the Americas.
Professor Andres Ruiz-Linares explained that research like this can provide biomedical information on the evolutionary processes that led to different adaptations also regarding certain facial features. Basically, it’s useful for better understanding the history of Asian and Native American populations but also for medical studies to better understand certain genetic problems. These are all ramifications of a history of humanity that continues to reveal its complexity.