A recent study led by researchers from University College London has identified genetic variants affecting tooth development, some of which were inherited from Neanderthals.
Dr. Kaustubh Adhikari, a researcher at University College London, stated, "Teeth can tell us a lot about human evolution, as well-preserved ancient teeth are particularly important for archaeologists, shedding light on milestones such as when we transitioned to cooked foods and when human tooth size began to decrease." He added, "However, little is known about the genetic basis of variation within modern human populations regarding tooth size and shape, partly due to challenges in measuring teeth."
The study involved data from 882 volunteers in Colombia with mixed European, Native American, and African ancestry. The dataset included measurements of dental crowns derived from 3D scans of dental plaster models.
Researchers compared these measurements with genetic information from participants in a genome-wide association study, employing a multi-omic analysis approach that integrates various data sources. One notable association pertained to a gene believed to be inherited from Neanderthals due to interbreeding with ancient Homo sapiens. This genetic variant, contributing to the biological pathway of tooth development, was found exclusively in individuals of European descent, with carriers exhibiting thinner incisors.
Overall, individuals of European ancestry had smaller teeth. The scientists also discovered associations with tooth dimensions in a gene known to affect incisor shape in East Asian individuals. The new study revealed that the gene, named EDAR, also determined the width of all teeth.
Dr. Qing Li, a researcher at Fudan University, remarked, "Some of the genes contributing to normal variation in tooth dimensions among healthy individuals may also contribute to pathological variation, such as tooth growth deficiencies or other dental health conditions." He expressed hope that their findings could have medical implications, suggesting that individuals with specific dental issues might benefit from genetic testing for diagnosis or potential genetic therapies for dental anomalies in the future.
Professor Andrés Ruiz-Linares, a researcher at University College London, Fudan University, and Aix-Marseille University, noted, "Our findings did not clarify whether the genes identifying tooth shape were selected during evolution due to particular advantages for dental health, suggesting that these genes may have been selected for influences in other areas, with tooth shape differences resulting as a secondary effect."