Dogs have been our companions for at least 17,000 years. During this time, they’ve evolved significantly, diverging from their wolf ancestors and resulting in a wide variety of breeds, many of which are specialized for specific tasks.
While it might seem that evolution has come to a halt, the truth is that it continues today.
Gene evolution. One way to observe this ongoing evolution is through genetics. In 2017, a team of biologists specializing in genetics and animal behavior at Linköping University in Sweden conducted an experiment that demonstrated that dogs’ social skills are linked to their ability to detect oxytocin, a hormone associated with bonding and trust.
In its study published in the journal Hormones and Behavior, researchers concluded that dogs’ ability to sense oxytocin has a strong genetic component that doesn’t manifest in the same way across all breeds.
Oxytocin. Oxytocin is a crucial element in the experiment. This hormone plays a significant role in how people connect with those around them, earning it the nicknames “love hormone” and “cuddle hormone.” Comprised of nine amino acids, oxytocin is secreted by the pituitary gland and functions as both a hormone and a neurotransmitter.
As a hormone, oxytocin acts on the mammary glands and uterus, influencing aspects of male reproduction as well. However, the hormone is primarily known as a neurotransmitter because it helps foster social and emotional bonds. Interestingly, this effect is observed not only in humans but also in many other mammalian species.
Aiming for human contact. The Swedish research team conducted an experiment focusing on oxytocin and how variations in sensitivity to this hormone influenced dogs’ behaviors when “seeking help” from their handlers. They also explored the role of canine genetics in this context.
The study involved 60 golden retrievers trained to open a jar to access a food reward. Researchers provided the dogs with a jar that had been deliberately sealed, making it impossible for them to retrieve the food. They timed how long each dog took to look at their handlers, indicating a request for assistance.
The dogs participated in the task twice. During one round, they received oxytocin via a nasal spray, while in the other round, they were given a neutral salt water spray as a control.
The evolution of dogs. The research team identified the genetic variants that caused dogs to react more strongly to the administration of an oxytocin spray than a neutral salt water solution.
Researchers also studied the genetics of approximately 20 wolves and discovered the same variant associated with increased sensitivity to oxytocin. This finding led the team to propose the hypothesis that the first domesticated wolves may have already carried this mutation.
A new wave of domestic dogs. The Linköping University experiment has recently gained media attention due to an article in The Atlantic. In it, experts at Duke University’s Canine Cognition Center in North Carolina hypothesize about a “third wave” in the domestication of dogs. According to them, the third wave is characterized by a shift in how humans relate to animals and coexist with them.
This shift represents a transition from a relationship focused on tasks typically associated with dogs (such as herding, hunting, and protection) to a more domestic and “urban” relationship, where dogs are primarily found indoors rather than outdoors. The change has occurred in just one generation.
In the article, experts also emphasize the significance of service dogs, noting that these dogs maintain a specific role beyond companionship. They reference the 2017 experiment to illustrate how genetic adaptations have allowed dogs to develop a closer bond with humans, facilitating their ability to care for and guide people effectively.
Image | Monika Simeonova
View 0 comments