Animal Behavior

Observational method

Watching and recording the frequency, duration, and intensity of behaviors in various contexts. It involves no manipulation of animal or environment.

Experimental method

Setting up a controlled experiment where one variable is controlled to determine its effect. It is powerful for identifying causality.

Comparative method

Comparing behaviors among related species or mapping onto phylogenies to understand the evolution of behaviors. It helps us understand where/when behaviors evolved.

Phylogeny

The study of the evolutionary history of a group of organisms, showing their relationships through a branching diagram.

Evolution

The theory that all species change through time and share a common ancestor.

Gregor Mendel

Discovered genetics, the missing link to Darwin’s ideas. He thought of a “particulate” theory of inheritance (alleles)

Evolution (Modern Synthesis)

The change in allele frequencies in a population over time

Natural selection (Modern Synthesis)

The differential (non-random) survival of alleles.

Adaptation (Modern Synthesis)

An inherited trait that enhances the survival and reproduction of an allele in a given environment.

Behavior

An adaptive trait: heritable (or built on heritable capacities), variable, and shaped by selection to improve survival and reproductive success in specific environments.

Parent-offspring regression

a quantitative-genetics method where you plot offspring phenotype against parent phenotype and fit a regression line; the slope estimates heritability of the trait

Selection experiments

Deliberate, multi-generation artificial selection studies where you choose breeders based on a trait (e.g., boldness, maze time, song rate) and track how the trait changes across generations. They directly test whether the trait is heritable and how fast it can evolve.

Behavioral Genetics

The study of how genes/the environment affect different traits

Instinctive/innate behaviors

Performed the same way each time, are fully expressed the first time performed, and are present in individuals raised in isolation

Knockout organisms

Animals engineered to have a specific gene sequence turned off

Microarray Analysis

Compares gene expression of many genes at once to identify which are active among different phenotypes

Proximate questions

1. What is the mechanism that causes the behavior?

2. How does the behavior develop?

Ultimate questions

1. What is the function of the behavior?

2. How did the behavior evolve?

Communication

When a specialized signal from one individual influences the behavior of another

Cue

Anything that gives off information that may or may not influence another

Signal

A packet of energy or matter that travels to a receiver because it evolved to do so

Communication modes

Acoustic, Visual, Tactile, and Chemical

Channel partitioning

Different species produce acoustical signals at different frequency ranges

Signals as indicators

1. The signaler and receiver’s interests are aligned (ex: bright poisonous prey)

2. The signal cannot be faked (ex: body size changes pitch in toads)

3. The signal is costly (wolf spider leg lifts)

Social learning

Learning by observing others

Cognition

The ability to generate and store mental representations of the environment to motivate behavior or solve problems (eg. numerical competency or innovation)

Morgan’s canon

States that an animal's behavior should not be interpreted as the result of a higher psychological process if it can be explained by a lower-level psychological process