Artificial Selection: Through selective breeding, humans influenced dog's physical characteristics. For example, some dog breeds were selected for their small size, while others for their large size. Traits like coat color, fur length, head shape, and body structure were also subjects to human preferences.
Behavioral Changes: Domestication changed dogs' behavior. Wild canines are inherently fearful of humans, while dogs evolved to be social companions, forming close bonds with humans and recognizing human cues and commands.
Coevolution: Dogs' evolution was also influenced by coevolution with humans. They accompanied humans during migration and settlement, adapting to various environments and forming symbiotic relationships with them.
Functional Traits: Certain dog breeds developed specific traits due to their intended roles. For instance, hunting dogs might have acute sense of smell, herding breeds tend to have strong herding instincts, and companion dogs are typically affectionate and sociable.
Behavioral Genetics: Advances in genetics have shed light on the genetic foundation of dog breeds. Studying the genomes of different breeds can help identify the genes responsible for specific traits, and selective breeding can amplify those traits.