The Sizes of Horns in Males of a Particular Beetle

question 62

Multiple Choice

The sizes of horns in males of a particular beetle have an interesting distribution: the highest frequencies are around 15 millimeters and 30 millimeters,with few individuals in between.Based on this observation,which evolutionary process is most likely to be operating on these horns?

• A) Stabilizing selection
• B) Directional selection
• C) Genetic drift
• D) Disruptive selection
• E) Mutation

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Definitions:

Discriminative Stimulus

A cue that signals the availability of reinforcement or punishment following a specific behavior, influencing its occurrence.

Secondary Reinforcers

Stimuli which become rewarding through their association with primary reinforcers, such as praise, tokens, or money.

Primary Reinforcers

Innate reinforcing stimuli that satisfy basic biological needs, such as food, water, and warmth.

Primary Reinforcer

A stimulus that is inherently rewarding and fulfills a basic biological need or desire.