Your teeth may contain Neanderthal heritage, study reveals

Although many people worry about the photogenic placement of their teeth, chances are that most don’t think about individual tooth shape. Well, you should – because it can be partially determined by your Neanderthal ancestry.

An international team of researchers, co-led by Kaustubh Adhikari from University College London (UCL), has found differences in teeth between ethnicities, including an apparent feature determined by a gene inherited from Neanderthals. Their research, published on December 12 in Current Biologymay one day help diagnose and treat genetic dental diseases.

The researchers, including experts from Fudan University in China, used 3D scans of dental plaster casts to analyze measurements of the teeth of 882 volunteers of European, Native American and African descent. They then compared these sizes to the volunteers’ genetic data and identified 18 regions of the genome involved in the size and shape of different teeth. Of note, 17 of these domains were identified for the first time as related to tooth size.

“Teeth can tell us a lot about human evolution, as well-preserved ancient teeth are particularly important to archaeologists, shedding light on stages such as when we switched to cooked food and human teeth began to decrease in size. But little is known about the genetic basis of variation in modern human populations in tooth size and shape, in part because of the challenges of measuring teeth,” said Adhikari at UCL statement. “We have identified multiple genes that influence the development of our teeth, some of which are responsible for differences between ethnic groups.”

Interestingly, scientists suggest that one of the identified genes originated from Neanderthals, with whom ancient humans interbred during our relatively brief prehistoric coexistence. The genetic variant, found only in volunteers of European descent, was associated with thinner incisors (measured from front to back). The researchers also note that individuals with this variant generally have smaller teeth. The team also found that the EDAR gene, previously linked to incisor shape in East Asians, also affects the width of all teeth.

However, “our findings did not shed light on whether the genes that identify tooth shape were selected for in evolution because of particular advantages for dental health, so it is possible that the genes were selected for their influence in other areas.” , with differences in the shape of the teeth arising as a side effect,” explained Andrés Ruiz-Linares of UCL and the University of Aix-Marseille, who led the study. Simply put, researchers aren’t sure why genes evolved to affect tooth shape in this way.

“Some of the genes that contribute to normal changes in tooth size among healthy people may also contribute to pathogenic changes, such as failed tooth growth or other dental health conditions,” said Qin Li of Fudan University, who co-led study. Pathogenic variations are genetic differences that increase an individual’s chances of developing a particular disease or genetic disorder. In other words, the genes that determine tooth measurements can also determine health problems.

Therefore, “we hope that our findings may be medically useful if people with specific dental problems can undergo genetic testing to aid in diagnosis, or if certain dental abnormalities can one day be treated with gene therapy. therapies,” Li added.

It remains to be seen how this research may lead to practical medical applications. Meanwhile, Neanderthal teeth join a host of other features we may have inherited from our long-lost relatives, including pain tolerance and nose shapes.