Lesson5: evolution&adaption

1. Phylogenetic adaptation

2. Ontogenetic adaptation

Behavioral variation results from the interaction between phylogenetic and ontogenetic adaptations.

1. Evolutionary changes in the genotype

2. Genetically programmed behavioral patterns

3. Adaptive in stable environments

1. Adaptation through learning during an individual’s lifetime

2. Includes individual and social learning

3. Adaptive in changing environments

1. Highly specialized

2. Rudimentary brains, little or no cortex

3. Poor learning abilities

4. Typical of invertebrates, fish, amphibians, reptiles

5. Exception: octopuses

1. Generalists

2. Complex brains

3. Developed individual and social learning

4. Typical of mammals, parrots, corvids

1. To develop a behavioral taxonomy of species

2. Focus on innate behaviors

3. Limited attention to learning and individual variation

1. Sign (key) stimulus

2. Supernormal stimulus

3. Fixed Action Pattern (FAP)

4. Displaced activity

5. Ritualization

• The innate vs. learned dichotomy is artificial

• Genotype expression depends on the environment

• Behavioral traits are highly environment-sensitive

• Reflexes and FAPs have strong innate components

1. The most basic behavior

2. Muscular response to a local stimulus

3. Motivation is irrelevant

4. Often part of more complex behaviors

1. The most complex innate motor actions

2. Triggered by a sign stimulus

3. Requires an appropriate motivational state

A sign stimulus (also called signal stimulus, key stimulus, or releaser) is an external stimulus that can trigger a Fixed Action Pattern (FAP) in a subject with an appropriate motivational state and in a favorable environment.

• Favorable environmental conditions

• Appropriate motivational state of the subject

• Presence of the specific external stimulus

The Umwelt of the species and its perceptual abilities.

Are sign stimuli the same across species?A:

No. A stimulus functions as a sign stimulus only relative to the sensory world (Umwelt) of a given species.

1. Visual

2. Acoustic

3. Chemical

4. Tactile

5. Any sensory modality

The behavior is not triggered (e.g., realistic stickleback model without red belly).

The behavior is triggered (e.g., unrealistic model with a red belly).

Even learned responses can be triggered by very simple models acting as sign stimuli.

Yes. All individuals of a species show the same FAP (with possible sex or age differences).

No. They are innate, but experience can modulate or refine their execution.

1. Presence of a specific sign stimulus

2. Appropriate motivational state

Yes. Many courtship behaviors consist of organized, repetitive FAP sequences.

Their morphology and duration show little or no individual variation.

Yes. Once initiated, the entire pattern is completed, although intensity may vary.

No. Feedback is relatively unimportant once the FAP has started.

Yes, in exceptional cases (e.g., nest-building movements without materials).

1. An irrelevant FAP occurring in situations of conflict or frustration

2. Example: courtship behavior during aggressive conflict

Yes. Electrical stimulation of specific brain areas (e.g., hypothalamus) can elicit FAPs.

Because behavior is less rigid than previously assumed and shows statistical variability.

1. Evolutionary transformation of behaviors into communicative signals

2. Often derived from displaced behaviors

Adaptive behavioral change resulting from experience, not genetically encoded.

1. Memory

2. Ability to associate experiences with survival

3. Exploratory tendency (curiosity)

No. All show simple learning, many show associative learning, few show complex learning.

Decreased response to a repeated, neutral stimulus.

Increased response to a stimulus following exposure to intense or aversive stimuli.

Unconscious memory facilitating recognition of previously experienced stimuli.

Learning and refinement of motor skills through practice.

1. Learning based on evaluations and inferences

2. Requires explicit memory

3. Includes insight learning

Immediate problem solving without trial and error, requiring prior knowledge.

Learning by observing and reproducing behaviors performed by others.

Social facilitation (contagion), which activates existing behaviors without learning.

Rapid, stable learning occurring during a sensitive (critical) period.

Following the first moving object after birth, forming a mother–offspring bond.

Precocial species.

Learning that influences mate choice at sexual maturity based on early exposure.

Bond formation by the mother immediately after birth.

Learning species-specific songs during a critical period.

Increased interaction with an object after observing a conspecific’s behavior.

Copying actions of others; cognitively complex; present in apes and cetaceans.

Active teaching adapted to the learner’s abilities; common in humans, rare in animals.

Information transmitted through social learning.

• Spontaneity

• Innovation

• Diffusion

• Standardization

• Stability

• Generational transmission

• Tradition

• Irrelevance