Your Dog Is Evolving, Too

Dogs could be undergoing a third wave of domestication driven by humans' desire for pets that are friendly, calm and well-suited to a sedentary lifestyle.

Just decades ago, canines were seen as working animals, tasked with hunting pests, herding livestock and guarding their homes. 

But today, companionship is a much higher priority for pet owners. 

Scientists have found that this shift has increased levels of a hormone responsible for social bonding in dogs, and especially in service dogs.