Why dogs are friendly - it's written in their genes

Dogs evolved tens of thousands of years ago from wolves.

Using molecular tools, geneticists led by Princeton University biologist Bridgett vonHoldt determined that dogs have the same genetic markers that are found in people with Williams-Beuren syndrome, a disorder characterized by developmental delays and "hypersocial" behavior. People with this condition tend to be highly outgoing, gregarious, empathetic, interested in prolonged eye contact, prone to anxiety and may have mild to moderate learn ing disabilities and intellectual impairment.

Their paper notes that little is still known about the genetics underpinning the behavioural traits associated with canine domestication compared to, say, the genetics responsible for differences in physical traits like fur colour and size.

The researchers studied the behaviour of 18 domesticated dogs and 10 wolves kept in captivity.

An interdisciplinary team of researchers, including those from Princeton University, sequenced a region of chromosome 6 in dogs and found multiple sections of canine DNA that were associated with differences in social behavior. We associate quantitative data on behavioral phenotypes symptomatic ofWBS in humans with structural changes in the WBS locus in dogs.

VonHoldt stresses that this study doesn't seek to explain the process through which dogs were domesticated, a hotly debated and controversial topic. The wolves were more likely to persist in the task and solve it, even if a person was nearby. A puzzle box lid was provided with a sausage as treat under it. The dogs were more likely to gaze at the person and not persist in the task.

Until now, scientists didn't really understand what happened genetically through the years that allowed dogs to thrive in human environments, said Monique Udell, an animal scientist at Oregon State and lead co-author of the study.

For the second test, a person sat down in a marked circle.

For the 'active phase, ' the person called the animal by name and encouraged contact, but did not leave the circle. Dogs differ from their closest cousins - wolves, in their friendliness towards humans and the gene that makes this possible has now been uncovered. In the passive phase, they sat quietly and ignored the animal by looking down on the floor.

One of the main reasons we like dogs so much is that they like us too. There are a lot of genes in the genome that probably contribute to dogs' demeanors - and she and her team have only investigated a fraction of them, she says. The only certain truth is that dogs are indeed descended from ancient wolves.

Anna Kukekova, an assistant professor in the Department of Animal Sciences at the University of IL at Urbana-Champaign who is familiar with the research but had no role in it, said that the paper points to these genes as being evolutionarily conserved, or essentially unchanged throughout evolution.

  • Sheila Mcguire