While most people focus on the overall appearance of their teeth, few consider the influence of genetics, particularly Neanderthal ancestry, on individual tooth shape. A recent study reveals a fascinating link between our ancient relatives and the subtle variations in our teeth. This groundbreaking research may pave the way for future advancements in diagnosing and treating dental conditions.
The study, published in Current Biology, involved an international team of researchers from University College London (UCL) and Fudan University in China. Using 3D scans of dental casts from 882 volunteers of European, Native American, and African descent, they analyzed tooth measurements and compared them with the participants’ genetic data. This meticulous analysis identified 18 genome regions linked to tooth size and shape, with 17 of these regions being newly discovered.
“Teeth offer valuable insights into human evolution. Archaeologists rely heavily on well-preserved ancient teeth to understand key evolutionary milestones, such as the transition to cooked food and the subsequent shrinking of human tooth size,” explained Kaustubh Adhikari of UCL. “However, the genetic basis of tooth size and shape variation in modern humans has remained largely unexplored due to the complexities of dental measurement. Our research has now identified numerous genes influencing tooth development, some of which account for the differences observed across various ethnic groups.”
Intriguingly, one of these genes appears to have originated from Neanderthals, with whom early humans interbred. This particular genetic variant, found exclusively in individuals of European ancestry, is associated with thinner incisors (measured from front to back) and generally smaller teeth overall. The study also confirmed the influence of the EDAR gene, previously linked to incisor shape in East Asians, on the width of all teeth.
However, the researchers acknowledge that the evolutionary advantage of these gene variations remains unclear. While we’ve identified the genes influencing tooth shape, we don’t yet know if they were selected for specific dental health benefits,” said Andrés Ruiz-Linares of UCL and Aix-Marseille University. “It’s possible these genes were selected for other reasons, and the tooth shape differences are simply a side effect.”
The implications of this research extend beyond evolutionary biology. “The genes responsible for normal variations in tooth dimensions can also contribute to pathogenic variations, such as tooth agenesis or other dental health issues,” explained Qing Li of Fudan University. This suggests that the genes determining tooth measurements might also play a role in dental disorders.
Looking ahead, the researchers hope their findings will lead to practical medical applications. “Genetic testing based on these findings could aid in diagnosing dental problems, and gene therapies might one day be developed to address certain dental anomalies,” added Li. While the full clinical potential of this research is yet to be realized, it highlights the enduring legacy of Neanderthal ancestry in shaping our modern human traits, down to the subtle curves of our teeth. It joins other inherited Neanderthal traits like pain tolerance and nose shape.
