The researchers tested the DNA of dogs and wolves to determine if mutations in a gene for friendly behavior in dogs are also linked to extreme friendliness in humans.
Dogs are very friendly to humans, much more so than wolves raised by humans. Because dogs are so important to us, many researchers have sought to understand how domestication has fundamentally changed dog behavior. Most researchers think this is some sort of fundamental genetic change. In humans, people with Williams-Beuren syndrome are often very confident and friendly, suggesting that the same genes that are affected in this syndrome may have evolved in dogs as well.
VonHoldt and his colleagues decided to test whether the same genes that are linked to Williams-Beuren syndrome in humans are also linked to friendliness in dogs. The study, as describe in Science, examined the behavior of 18 dogs, including purebreds and mixed breeds, as well as 10 wolves raised by humans. They sequenced the DNA at the level of the GTF21 and GTF21RD1 genes, which are involved in Williams-Beuren syndrome in humans.
The researchers found that the dogs were significantly friendlier than the wolves raised by humans. They also found that dogs had more mutations disrupting gene activity in GTF21 and GTF21RD1 than wolves. These genes code for a protein that regulates other genes. A similar disruption of GTF21 function in mice leads to the same social behavior in dogs.
This study has interesting implications for understanding personality and behavior as well as domestication. Dogs were one of the first animals to be domesticated, and this gene probably played a role. One researcher described it as “survival of the nicest.” Humans, being much more social than other primates, have likely experienced similar changes in their own genes.
Written by CI Villamil
E Penninsi. What Makes Dogs So Friendly? (Science). http://www.sciencemag.org/news/2017/07/what-makes-dogs-so-friendly-study-finds-genetic-link-super-outgoing-people