Behavioral Biology: Proximate and Ultimate Causes of Behavior

Free Response

Describe Pavlov’s dog experiments as an example of classical conditioning.


Dogs salivated in response to food. This was the unconditioned stimulus and response. Dogs exposed to food had a bell rung repeatedly at the same time, eventually learning to associate the bell with food. Over time, the dogs would salivate when the bell was rung, even in the absence of food. Thus, the bell became the conditioned stimulus, and the salivation in response to the bell became the conditioned response.

Describe the advantage of using an aural or pheromone signal to attract a mate as opposed to a visual signal. How might the population density contribute to the evolution of aural or visual mating rituals?


Animals that use aural or pheromone signals to communicate with potential mates are able to signal over longer distances. Sound waves and chemicals can diffuse out into an environment while visual cues require a direct line of sight between the sender and receiver. Animals that use aural cues to acquire mates probably exhibit a lower population density than animals that use visual cues.