Our Ever-Changing World – Advances in Canine Science

BY CAROLINE COILE

A DOG-OWNING GENE?

Chances are, you and I share one very important gene. A team of European scientists studied 35,035 human twin pairs to understand if human genetics influence the desire to own a dog. The researchers found concordance rates of dog ownership to be much larger in identical twins than in non-identical ones — supporting the view that genetics indeed plays a major role in the choice of owning a dog. Their results suggest that genetic variation explains more than half of the variation in dog ownership. The researchers speculate that, regardless of upbringing, some people have a higher innate propensity to care for a pet than others. So everyone reading this magazine probably has the same genetic make-up when it comes to that!

Co-author Carri Westgarth cautions that the findings could impact the idea that owning a dog has health benefits. “Supposed health benefits of owning a dog reported in some studies may be partly explained by different genetics of the people studied.”

Tove Fall, Ralf Kuja-Halkola, Keith Dobney, Carri Westgarth, Patrik K. E. Magnusson. Evidence of large genetic influences on dog ownership in the Swedish Twin Registry has implications for understanding domestication and health associations. Scientific Reports, 2019; 9 (1) DOI: 10.1038/s41598-019-44083-9

THE “PUPPY DOG EYES” MUSCLE

Researchers analyzing the facial behavior and anatomy of dogs and wolves found that the facial musculature of both species was similar except for the muscles above the eyes. Dogs have a small muscle, which allows them to raise their inner eye-brow, that in wolves is just a “scant, irregular cluster of fibers.” Researchers attribute this inner eyebrow raising to an evolutionary advantage that elicits nurturing from humans because the movement makes the eye appear larger, more infant-like and sadder—-in other words, “puppy dog eyes.” Previous research showed dogs moved their eyebrows significantly more when humans were looking at them compared to when they were not looking at them.

The authors compared four wolves from Michigan and Alaska and one each of Labrador Retriever, Chihuahua, German Shepherd Dog, Bloodhound, Siberian Husky and Mongrel. The only dog in the study that did not have the muscle was the Siberian Husky, which is among the more ancient dog breeds.

Co-author Adam Hartstone-Rose, at North Carolina State University, says, “These muscles are so thin that you can literally see through them — and yet the movement that they allow seems to have such a powerful effect that it appears to have been under substantial evolutionary pressure. It is really remarkable that these simple differences in facial expression may have helped define the relationship between early dogs and humans.”

J. Kaminski, et al. Evolution of facial muscle anatomy in dogs. Proceedings of the National Academy of Sciences, June 17, 2019; DOI: 10.1073/pnas.1820653116

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Posted by Alex on Jul 15 2019. Filed under Current Articles, Featured. You can follow any responses to this entry through the RSS 2.0. Both comments and pings are currently closed.