How Neanderthal Genes Affect European Tooth Size

UK: Neanderthal genes among people with European ancestry play a part in the size of their teeth, according to a new study. Scientists say inbreeding with the human-like species thousands of years ago continues to influence the genetic differences among human beings.

Study Methodology and Findings

According to the study by researchers at University College London, about 880 volunteers from Colombia with mixed ancestry — European, Indigenous, and African — provided dental plaster casts for the researchers to analyze. They compared the measurements of the teeth with the volunteers’ genetic background, identifying 18 genome regions that control the size and shape of different groups of teeth.

“One of these genes can be traced back to Neanderthals, which leads to thinner incisors — the eight front teeth,” the study noted. The gene was only found among people with European descent, as highlighted in the study published in the journal Current Biology.

The study’s lead author, Dr. Kaustubh Adhikari, explained, “The ‘thickness’ of the incisors we are talking about is the overall dimension of the incisor from front to back, not the thickness of the enamel layer. The variation in overall thickness that we observe, given that these are all healthy people with no dental malformations, is modest.”

Impact on Dental Health

Dr. Adhikari noted that having thinner teeth doesn’t necessarily mean they are more prone to cracking or sensitivity. “In other words, the slightly thinner teeth that some of these people have, due to the gene we identified, are not a bad thing,” he said. “So nothing to worry about — it’s all part of normal human variation.”

Co-lead author Professor Andres Ruiz-Linares pointed out that the study’s findings are inconclusive about whether evolutionary advantages played a part in the size and shape of teeth. “Our findings did not shed light on whether the genes that identify tooth shape were selected in evolution due to particular advantages to dental health,” Ruiz-Linares said. “So it’s possible that the genes may have been selected due to the influences they have in other areas, with tooth shape differences resulting as a side effect.”

Broader Implications

This study underscores the complex genetic history of modern humans, highlighting how ancient interactions with Neanderthals continue to affect physical traits like tooth size and shape. The study also contributes to the broader understanding of human evolution and genetic diversity.

“This research adds to the evidence that our relationship with Neanderthals wasn’t just a one-off event,” said Ruiz-Linares. “It suggests that interbreeding may have played a more significant role in shaping the genetic makeup of modern Europeans than previously thought.”

The study, while shedding light on the genetic roots of dental traits, leaves open questions about the evolutionary pressures that may have influenced these traits over time. The researchers emphasize the need for further studies to fully understand the implications of these genetic links.

“This is just one piece of the puzzle,” Adhikari concluded. “Understanding the full range of Neanderthal influences on human genetics is still a work in progress.”