A Biologist Studied a Population of Squirrels for 15 Years

question 48

Multiple Choice

A biologist studied a population of squirrels for 15 years. During that time, the population was never fewer than 30 squirrels and never more than 45. Her data showed that over half of the squirrels born did not survive to reproduce, because of both competition for food and predation. In a single generation, 90% of the squirrels that were born lived to reproduce, and the population increased to 80. Which inference(s) about this population might be true?

• A) The amount of available food may have increased.
• B) The parental generation of squirrels developed better eyesight due to improved diet; the subsequent squirrel generation inherited better eyesight.
• C) The number of predators that prey upon squirrels may have decreased.
• D) Both A and C could be true.

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Definitions:

Conditioned Stimulus (CS)

In classical conditioning, a previously neutral stimulus that, after becoming associated with an unconditioned stimulus, evokes a conditioned response.

Stimulus Discrimination

The ability to distinguish between different stimuli, even if they are similar, based on learned responses.

Stimulus Generalization

The tendency for the conditioned response to be elicited by stimuli that are similar to the conditioned stimulus.

Spontaneous Recovery

The return of a conditioned response that had previously disappeared, following a break from being exposed to the associated stimulus.