Final answer:
Dogs with round eyes that blink generally show traits of social neotony, which are selected to foster closeness with humans. However, protruding eyes can also indicate hyperthyroidism, a medical condition.
Step-by-step explanation:
Dogs that have round eyes that blink are generally demonstrating social neotony, a set of traits that makes them appear more juvenile and endearing to humans. This feature, along with a smaller snout, a more globular skull, and fewer and smaller teeth, is part of the domestication process where dogs have evolved to show physical traits that foster a closer and more submissive relationship with humans. Additionally, specific breeds like Bloodhounds are selectively bred for enhanced senses, like a better sense of smell. However, it's important to note that protruding eyes can also be a sign of medical conditions such as hyperthyroidism, as seen in humans with Graves' disease, rather than a trait selected for social reasons.