Have you ever wondered why your Cocker Spaniel loves to sniff so much, or why your Border Collie literally runs circles around you?
Well, scientists and a team from the National Human Genome Research Institute in Maryland think they’ve cracked the genetic code.
By analyzing the DNA of more than 200 dog breeds, they were able to classify them into ten groups based on their genetic lineage.
Each group also showed specific behaviors, and experts were able to link them to specific genes the dogs shared.
By analyzing the DNA of more than 200 dog breeds, the researchers were able to classify them into ten groups based on their genetic lineage. Pictured: a visual representation of the ten subspecies groups
The team first analyzed the DNA of 4,000 dogs, coming from more than 200 dog breeds. This allowed them to group them by genetic lineage, resulting in ten groups. Next, they found dog-specific behaviors in each of the 10 groups, before conducting a genome-wide association study to identify the genetic variants responsible for them.
The domestication of dogs is known to have occurred at least 15,000 years ago, when gray wolves and dogs diverged from the extinct wolf species.
Wolves will live on the outskirts of hunting-and-gathering camps and feed on human-made waste, according to Dr. Krishna Viirama of Stony Brook University, who was not involved in this study.
‘Those wolves who were tame and less aggressive would have had more success with this,’ he told MailOnline, ‘and while humans did not initially gain any sort of benefit from the process, over time they would have developed a kind of symbiosis. [mutually beneficial] The relationship with these animals eventually evolved into the dogs we see today.
Over the years, humans began selectively breeding dogs to be able to perform specific jobs, which eventually led to today’s breeds.
‘The largest and most successful genetic experiment ever undertaken by humans is the creation of 350 dog breeds,’ said lead researcher Dr Elaine Ostrander.
“We needed dogs to herd, we needed them to guard, we needed them to help us hunt, and our survival depended closely on that.”
Over the years, humans have selectively bred dogs to be able to perform specific jobs, such as pulling a sled, which eventually led to today’s breeds (stock photo)
In their study, published today in Cell, the researchers wanted to identify the unique genes that humans were inadvertently honing in that gave dogs their desirable behaviors.
However, some behaviors may be related in part to physical traits, such as long legs or a nose, that have also been selected for through selective breeding.
“So identifying the genetics of canine behavior can be complex,” said first author Emilie Dutroux.
The team analyzed the DNA of 4,000 purebred, mixed and semi-feral dogs, as well as wild dogs, coming from more than 200 dog breeds.
Next, they classified all the breeds into ten groups, each of which shared a major genetic ancestry.
It became clear that each of these groups contained breeds historically used for a specific task, such as herding livestock, hunting by scent, or hunting by sight.
This indicates that the breeds within the group shared a common set of genes that resulted in behaviors that made them well suited to their role.
Ten groups of dogs with unique behaviors
- Spaniel proportions indexReducing aggression directed at strangers and reducing aggression directed at dogs. Historical Functions: Many were used as “gun dogs”, assisting hunters by pointing at game, shooting game into the air, etc. Breed Examples: Cocker Spaniel, English Springer Spaniel, Irish Setter, German Shorthaired Pointer, Vizsla
- Herder lineage: a very strong positive association with antisocial fear, which is similar to anxiety-like responses. Historical functions: Protecting or moving livestock, a subset of which does so by grazing. Breed Examples: Border Collie, Shetland Sheepdog, Pembroke Welsh Corgi, Australian Cattle Dog
- Pedigree sled dogModerate predatory instinct and low trainability. Historically used to carry loads (people and things). Breed Examples: Alaskan Malamute, Siberian Husky
- dog pedigreePositive relationships with dog-directed fear, aggression, rivalry, antisocial fear, and predatory drive. Historically, group dog breeds were used to control vermin or by hunters to flush prey out of hiding places. Breed Examples: Jack Russell, Wire Fox Terrier, Cairn Terrier, Irish Terrier, Wheaten Terrier, Airedale Terrier
- The scent of a pedigree dogStrong negative association with trainability. Positive associations with antisocial fear and rivalry between dogs (familiar canine aggression). These breeds are generally used by hunters to track game, primarily by scent tracking. Breed Examples: Bloodhound, English Foxhound, Petit Basset Griffon Vendeen
- Retriever Pedigree: low predator engine. HISTORICAL FUNCTIONS: Gun dogs and water dogs are specifically used to retrieve game. Breed Examples: Labrador Retriever, Golden Retriever, Chesapeake Bay Retriever
- Asian Spitz PedigreePositive association with owner-directed aggression and a negative association with trainability. This lineage is determined more by geographic origin than by the work’s historical role. The Asian Spitz breed includes a wide variety of working breeds including hunting dogs and guardians. Examples of the breed: Chow Chow, Akita, Tibetan Mastiff, and Shiba Inu
- Sighthound pedigree: decreased energy and excitability. These breeds were historically used for hunting because of their speed (and use of “sight” rather than scent). Breed Examples: Irish Wolfhound, Whippet, Greyhound, Borzoi
- African and Middle Eastern ancestryBreed example: Rhodesian Ridgeback
The researchers then surveyed 46,000 owners of purebred dogs within each group to determine the behavioral tendencies of their dogs.
Dogs, which are used to hunt and kill prey, for example, have been frequently reported as having a high prey drive.
After identifying the typical behaviors of dogs within each group, the researchers wanted to see if they could identify any specific genes associated with them.
Since they demonstrate this unique and easily identifiable trait of instinctively bringing animals closer, they decided to do so with herding dogs.
They performed a genome-wide association study on the DNA samples, which identified any genes associated with grazing behaviour.
It was found that herding dogs showed a genetic variant linked to “axial orientation,” which helps their neurons communicate with their brain.
It was found that herding dogs showed a genetic variant linked to “axial orientation,” which helps their neurons communicate with their brain. One of the axonal directing genes identified in herding dogs, EPHA5, has also been associated with ADHD and anxiety-like behaviors in other mammals. Thus it can be linked to the high energy levels and hyperfocus of sheep herding breeds such as Border Collies (stock image)
One of the axonal directing genes identified in herding dogs, EPHA5, has also been associated with ADHD and anxiety-like behaviors in other mammals.
It can thus be linked to the high energy levels and excessive focus of sheepherding breeds such as Border Collies.
“The same pathways involved in human neurodiversity are implicated in behavioral differences between dog breeds, suggesting that the same set of genetic tools could be used in both humans and dogs,” said Dr. Dutroux.
Herding dogs also had genes more important for the development of brain regions involved in interpreting social information and learning fear responses.
“After 30 years of trying to understand the genetics behind herding dogs, we are finally beginning to unravel the mystery,” added Dr. Ostrander.
How man changed his best friend: experts reveal what dogs used to look at
Shocking photos have revealed what the dogs used to look like, amid warnings that breeds like the Pug and French Bulldog are being cruelly bred for fashion’s sake.
From German Shepherds to Basset Hounds, many breeds have changed dramatically after years of selective breeding.
Boxers were bred to have shorter faces with a larger mouth, while their backs and necks were elongated and their legs shrunken to the point where it was difficult for them to maneuver over obstacles a few inches off the ground.
Meanwhile, pugs were bred to have compact noses and large eyes, which put them at high risk for a range of health conditions, including breathing, eye and skin disorders, according to a new study.
Justin Shotton, President of the British Veterinary Association (BVA), explained, “Extreme characteristics that many owners find so attractive, such as squashed faces, large eyes and curled tails, seriously jeopardize the health and well-being of their pugs, often resulting in lifelong suffering.” . .
“While these extreme unhealthy characteristics remain, we will continue to strongly recommend to prospective owners against purchasing brachycephalic breeds such as the Pug.”
Read more here
Pugs were bred to have compressed noses and large eyes, while Boxers have shorter faces with larger mouths, and Bull Terriers have deformed skulls and thicker bellies.
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