Problem 2 - Biology: The Dynamic Science

Question

A stimulus that always causes an animal to behave in a highly stereotyped way is called: a. fixed action pattern. b. an instinct. c. habituation. d. a sign stimulus. e. a reinforcement.

Step-by-Step Solution

Answer

The correct answer is d. A sign stimulus.

Step 1: Understanding the Options

First, look at the different options and understand the meaning of each one. - A fixed action pattern is an instinctive behavioral sequence that is unchangeable and usually carried to completion. - Instinct is an innate or inbuilt behavior that is specific to a species. - Habituation is a form of learning in which an organism decreases or ceases its responses to a stimulus after repeated presentations. - A sign stimulus is an external sensory stimulus that triggers a fixed action pattern. - Reinforcement is a term used in operant conditioning to refer to anything that increases the likelihood that a response will occur.

Step 2: Choosing the Correct Answer

The question is asking for a stimulus that always causes an animal to behave in a highly stereotyped, predictable, and reliable way. This perfectly describes a sign stimulus, which triggers an instinctive behavior known as the fixed action pattern.

Key Concepts

Fixed Action Pattern

A fixed action pattern is a fascinating aspect of animal behavior. It is a sequence of actions that an animal instinctively knows how to perform. These actions are hardwired into the animal's brain and occur in response to a specific stimulus. Once they start, they are usually carried out to completion, regardless of any changes in the environment. This behavior ensures that the animal performs actions critical for survival and reproduction without the need to learn them. Fixed action patterns are considered stereotypic because they are repetitive and predictable. For example, a bird building a nest follows a fixed action pattern; it performs the same steps instinctively every time without deviation.

Instinct

Instinct refers to inherited behaviors that are characteristic of a species. These are inborn and not learned behaviors that guide animals from birth. Instincts are crucial for survival, as they help animals respond to fundamental needs such as finding food, shelter, and mating. Unlike behaviors acquired through learning, instinctual actions occur naturally and spontaneously. For example, a sea turtle hatchling instinctively moves toward the sea after emerging from its egg. This instinctual response does not require prior experience or learning; it is part of the animal's genetic makeup.

Sign Stimulus

A sign stimulus is a key concept in understanding fixed action patterns. It's an external trigger that prompts a fixed action pattern in animals. Sign stimuli are often specific in nature, meaning only certain stimuli can trigger a particular behavioral response. These stimuli ensure that behavior occurs in an appropriate context, enhancing an animal's chances of survival. For instance, the red belly of a male stickleback fish is a sign stimulus that triggers aggressive behavior in other male sticklebacks. The sight of the color red in their environment leads them to attack to defend their territory.

Learning Types

Learning involves the process by which animals acquire new behaviors or modify existing ones. It contrasts with instinctual behaviors, as learning results from experience rather than inheritance. There are several types of learning, each serving different adaptive purposes:

• Habituation: This type of learning involves decreasing responsiveness to a repeated stimulus. For example, birds may stop responding to a loud noise if it occurs frequently and doesn't pose a threat.
• Classical Conditioning: Here, animals learn to associate a neutral stimulus with an important one, leading to a change in behavior.
• Operant Conditioning: This is learning through consequences, where behaviors increase or decrease in response to rewards or punishments.
• Observational Learning: Also known as social learning, it occurs when animals watch and imitate the actions of others.

Learning types provide flexibility to animals, allowing them to adapt to new environments and situations.