Is this why dogs became man’s best friend? Scientists discover gene mutations that reduce stress and make puppies more comfortable interacting with people
- Scientists tested the social attachment of 624 pet dogs to humans
- “Ancient” races spent less time looking at people than “general” races
- The team then analyzed their genomes to check if genetic mutations played a role
- They found 2 mutations in the gene involved in the production of stress hormone
- The results suggest that these mutations played a role in their domestication
Dogs were first domesticated around 29,000 years ago and have since become one of the most popular types of pets around the world.
But why exactly the animals became “man’s best friend” was previously unclear.
Now scientists at Azabu University in Japan think they have the answer after discovering two key gene mutations in dogs.
These mutations may have played a role in their domestication by reducing stress and making the puppies more comfortable around humans, the team says.
Dogs were first domesticated around 29,000 years ago and have since become one of the most popular types of pets around the world
Dogs were bred to have facial expressions like HUMAN
Researchers at Duquesne University in Pittsburgh recently found that dogs have facial muscles similar to humans, allowing them to form facial expressions similar to our own.
Their results suggest that these traits have been selectively bred by humans for the past 33,000 years, since our ancestors first bred wolves.
“Throughout the domestication process, humans may have selectively bred dogs based on facial expressions similar to their own, and over time canine muscles may have evolved to become ‘faster,’ further enhancing communication between dogs and humans.” said Professor Anne Burrows, senior author of the study.
Previous studies have shown that changes in various genes may have played a role in dog domestication.
So far, however, scientists have not been able to determine exactly which genetic mutations could be involved.
“During domestication, dogs underwent strong selection for temperament, behavior and cognitive abilities,” the team wrote in their study, published in Scientific Reports.
“However, the genetic basis of these abilities is not well understood.”
A group of 624 domestic dogs was split into two groups — the Ancient group, made up of breeds genetically closer to wolves, such as Akita and Siberian Husky, and the General group, which included all other breeds — before completing two tasks .
In the first task, the dogs had to decide under which bowl food was hidden based on cues from the experiments such as pointing, staring, and tapping.
This tested the dog’s understanding of human gestures and communication.
The results showed that there was no significant difference in performance between the Ancient and General breeds.
In the second task, the dog was given a problem-solving test of trying to open a container to get food.
Their analysis revealed that two mutations in MC2R were associated with both the correct interpretation of gestures in the first task and the experimenters glancing more frequently in the second task (stock image).
During this task, the researchers noted the frequency and length of time the dog spent looking at the experimenters, reflecting their social bond with humans.
The results showed that dogs in the Ancient group looked at the experimenters less often than dogs in the General group, suggesting they were less attached to humans.
To see if genetic mutations might help explain the findings, the researchers then looked at differences in the genes linked to the dogs’ cognitive abilities.
These included the genes for the “love hormone” oxytocin (OT) and genes for the melanocortin-2 receptor (MC2R), which is involved in the production of the stress hormone cortisol.
Their analysis revealed that two mutations in MC2R were associated with both the correct interpretation of gestures in the first task and the experimenters glancing more frequently in the second task.
“The MC2R gene was most effective for dogs’ abilities in two-way selection tests and problem-solving tasks, suggesting that this gene can be mutated early in the dog domestication process,” the researchers concluded.
OXYTOCIN: THE ‘LOVE’ OR ‘CUDDLE’ HORMONE RESPONSIBLE FOR TRUST
Known as the “love hormone,” oxytocin inspires trust and generosity.
The chemical is released naturally from the brain into the blood of humans and other mammals during social and sexual behavior.
It is produced by women during labor to help them bond with their baby and stimulates the production of breast milk.
The chemical is also released during lovemaking, earning it the nickname “cuddle hormone.”
Other loving touches, from hugging a teddy bear to petting your dog, also trigger the release of the hormone.