UA Little Rock Research Sheds New Light on How Domestication Shaped the Canine Voice Box

Dogs may be humanity's oldest companions, but their evolution from wild wolves is still full of mysteries. New research from the University of Arkansas at Little Rock is helping solve one of them by showing how domestication may have altered far more than behavior.

Jacob Hansen, a graduate student in biology, and Dr. Raffaela Lesch, assistant professor of biology, have published a groundbreaking study demonstrating that domestication reshaped the canine larynx, the organ responsible for sound production. It's the first anatomical test of a major scientific concept called the neural crest domestication syndrome (NCDS) hypothesis.

"This is the first study to test whether selection for tameness affects the voice box," Hansen said. "We found measurable differences between the larynges of dogs and wolves, which supports the idea that domestication doesn't just change behavior but also changes anatomy."

The team's research, which was published in the Royal Society Open Science journal in July, offers rare anatomical insight into how domestication impacts the development of the voice box via neural crest cells, which are embryonic cells that influence everything from skull shape to vocal folds. While the NCDS hypothesis has previously been used to explain behavioral and physical changes in domesticated animals, no one had applied it to the larynx before.

To conduct the study, Hansen and Lesch used CT scans to analyze and compare the larynges of domestic dogs and wolves. They identified 108 specific anatomical landmarks and worked with international collaborators to gather laryngeal specimens from across Europe. Their co-authors include Nicole D. S. Grunstra, W. Tecumseh Fitch, Andrew C. Kitchener, and Michaela Gumpenberger.

"We saw significant differences in the size and shape of the larynx and vocal folds between dogs and wolves," Hansen said. "Dogs, particularly mesocephalic breeds with medium-length snouts, had smaller larynges and shorter vocal folds."

Those differences suggest that the evolution of dogs' friendly and expressive behavior may have come with vocal trade-offs. Lesch, who mentored Hansen throughout the project, said the findings help validate a core prediction of the NCDS hypothesis: that selection for tameness reduces neural crest cell migration, which in turn influences multiple body systems.

"The larynx is largely derived from neural crest cells," Lesch said. "The fact that we see structural changes in this organ supports the idea that domestication has widespread anatomical effects. This occurs not just on the visible features like ears or snouts, but on deeper systems that affect communication."

Their work also hints at larger implications. Some researchers believe humans underwent a process of "self-domestication," evolving to become more sociable and cooperative over time. If so, studies like this could provide a biological roadmap to investigate how human anatomy may have changed as a result, according to Lesch.

Co-authors hail from research institutions in the U.S. and Europe, including Austria's University of Vienna and the University of Veterinary Medicine Vienna, as well as the National Museums Scotland, reflecting the international collaboration behind the study.

To view these students click here: https://ualr.meritpages.com/achievements/UA-Little-Rock-Research-Sheds-New-Light-on-How-Domestication-Shaped-the-Canine-Voice-Box/194800