1) What are the mechanistic causes of the behavior?

2) How does the behavior develop?

3) How did the behavior evolve?

4) What is the function of the behavior?

ABC's of Animal Behavior:

Animal Behavior =

• Provides the best
  evidence of causal relationships.
• Eliminates confounds via the rule of one variable.
• We can't or shouldn't manipulate some things.
• High Internal validity
• Low External Validity
  

1) What are the mechanistic causes of the behavior?

2) How does the behavior develop?

Ex: Why do owls fly quietly?

-Because their flight feathers are soft.

3) How did the behavior evolve?
4) What is the function of the behavior?

Ex: Why do owls fly quietly?

-To avoid alerting their prey and interfering with their own hearing.

1. Variation: Individuals vary

2. Heritability: Variation is “heritable”

3. Differential Reproduction: Some individuals produce relatively more offspring (Difference in Fitness)

___________ and ___________

determine the rate of evolution.

P = G + E + (G x E)

Where G is the Genetic component

E is the environmental component

and it includes the interation between the two.

1.) Selection

2.) Evolve

Raise animals with suspected genetic differences in the same environment (a common garden).

Determines if behavior has a genetic component.

Screen populations for outstanding variation, or "mutants".

Mutants can be studied using genetic tools to discover the molecular basis of the mutation.

Experimenter selects the individuals that give rise to the next generation.

Can directly assess the potential for evolutionary change in behaviors.

Compare individuals related by difference degrees.

Compare if they were raised together or apart.

Assess correlations among traits.

• act on receptors in the nucleus.
• affect DNA transcription (and consequently protien production).

• act on membrane-bound receptors
• activate a cascade of actions.
• cause production of enzymes that control or alter cell functions.

Development of behavioral mechanisms (such as neural circuits, structures, etc.).

Usually occurs early in life.

Usually long-term.

Expression of behaviors.

Usually occur in adulthood.

Involve subtle changes in already established neural circuits.

1. Receive Input
(sensory neurons)

2. Transmit & Process
(interneurons)

3. Generate Output
(motor neurons)

1.) Resting potential

2-3.) Depolarization

(away from -70mV in a + direction)

4.) Repolarization

(back towards -70mV)

5.) Hyperpolarization

(more negative than -70mV)

When Action Potentials occur

AKA separate "pulses".

"Fuse - release - diffuse - bind"

1.) AP reaches terminal, causes influx of Ca2+ ions.

2.) Causes vesicle fusion & transmitter release.

3.) Transmitter binds to receptors on ion channels in the postsynaptic cell, causing them to open.

EPSP - “excitatory postsynaptic potential"

IPSP - “inhibitory postsynaptic potential”

Give rise to APs if the AP threshold is met.

Exciting system "A" often inhibits system "B"

Important motif in neural processing.

When first triggered, systems fight to be first.

If system "A" wins out, it inhibits B until it experiences adaptation and B experiences a post-inhibitory rebound and inhibits A.

Turns oscillators off and on.

Can send either excitatory or inhibitory inputs.

Transduce environmental stimuli.

Involves ion channels, depolarization, and neurotransmitter release.

Neurotransmitter release elicits APs in sensory neurons.

Processes and computes information.

Integrates sensory inputs with each other and with motor output.

A US (air puff in eye) leads to a UR (a blink).

Repeated CS-US pairings lead to a CS-CR relationship.

Ex: Repeated Bike Horn(CS)-Air Puff(US) pairings lead to a Bike Horn(CS)-Blink(CR) association.

Generalization/Discrimination in

Classical Conditioning

1. A horn-blink association is conditioned.

2. Then we pair “horn + light flash” with eye puff.

3. Conditioning will not develop for the light flash.

4. We say that the existing horn-blink association blocks conditioning to the light.

He did experiments with puzzle boxes and cats.

Learning is incrimental not insightful!

Driven by the idea of the Law of Effect.

A situation becomes associated with a response that produces a reinforcing outcome.

– The modification of behavior by experience

• Change should be ‘long-lasting’
• Not caused by a wear or fatigue, etc

Learning/conditioning via Synaptic Plasticity

(The Hebbian Model)

The enzyme Adenyl cyclase requires Ca2+ from
previous action potentials and serotonin from
another neuron to make cAMP, which creates
more vesicles of neurotransmitter

Long-term plasticity involves changes in
gene expression: modifying the cAMP
pathway and growing more synapses

Assuming that fitness increases with rate of
gain, and that patches deplete, we predict:

1. Animals will spend more time exploiting
patches in poor habitats (travel time long), and
2. Less time exploiting patches in rich habitats
(travel time short)

1. A fitness surrogate or currency (e.g rate of foodgain, number of mates acquired, number of offspring produced)

2. Variation among behavioral phenotypes fors election to act on (e.g., differences in what time of day that males court females)

3. Constraints: assumptions that connect 1 & 2
(e.g., the curves relating behaviors to their fitness costs and benefits)

Goal - to maximize rate of food energy intake.

R = E/(h+s)

Where R = rate of food energy intake

E = energy gain from consumption

h = handling time

s = search time

When Enew/hnew

is less than or equal to

Eaverage/(haverage + saverage)

• Always attack the best type…

– because they can’t miss any opportunities
by taking the best thing

• Attack worse things only if better things

are hard to find…
– because opportunities to get best item
could be “lost” while handling worse items

The costs and benefits of a particular behavioral
“strategy” depend on the frequency of other strategies in the population.

The rarer phenotype has the advantage.

Currency = evolutionary fitness

Used to predict evolution of behaviors with frequency dependent costs and benefits.

Use a payoff matrix.

Determines which behavioral strategies are evolutionarily stable

A pair of strategies of X & Y represent a Nash Equilibrium if:

– X is the best reply to Y, and
– Y is the best reply to X

– X is an ESS if no alternative strategy can invade a population of (almost) all X’s

– This is always true if X vs. X is a Nash Equilibrium; in an ESS X is the best reply to itself!

In the popular Hawk-dove game, they change their strategy based on if they are owner or intruder.

• If owner, play Hawk
• If intruder, play Dove

Convention and Assessment

1. Convention: Use some sort of arbitrary,
conventional rule to settle the contest.

2. Assessment: Predict the likely winner in advance
by assessing your rival’s Resource Holding
Potential (RHP)

Females in Reproduction

(Or few-large gamete producers)

Usually:

• have few and large gametes
• selective of mates
• invest a lot in their offspring
• number of mates has little effect on fitness
• less aggressive

Males in Reproduction

(Or many-small gamete producers)

Usually:

• not selective of mates
• little investment in offspring
• fitness increases with # of mates
• more aggressive

Intra-sexual Selection includes:

4 Things

• Fighting
• Mate-guarding
• Sperm competition
• Alternative male tactics

Differences between the sexes of one species.

Only males possess “horns” (which are
really just enlarged mandibles) for fighting to obtain females.

Genetic or a behavioral polymorphism…

Involves sneakers, female-like males, and satellite males that intercept females on their way to dominant males.

Trait indicates some aspect of a male’s genetic or
physiological quality.

Male has passed a "test" by having the trait.

Trait and preference co-evolve in a positive feedback loop that “runs away”.

Over time, preference and trait become genetically linked. Females either prefer or do not prefer a trait. Females that prefer a trait will only mate with males with the trait. Females with no preference mate indescriminately.

Pair formation between one male and one female;
can be long or short.

• Enforced my females
• OR so the male can guard the female
• OR so the male can assist the female in caring for the offspring. In situations where offspring survival would be reduced without male care.

Males actively search for receptive females
– do not defend females or resources

Females usually scattered.

Males aggregate in so-called leks where they display (sing, dance, gyrate) to attract females.

– do not provide parental care
– do not defend females or resources
– do not actively search for mates

•Males often have low confidence in paternity
•Males often have the first opportunity to desert
•Females often have a more intimate association with young and may be better able to provide care

•We expect females to be predisposed to parental care because they are more invested in each offspring

Function of Communication for the

Signaler

Function of Communication for the

Receiver

What makes a good Signal?

4 Things

−aggressive calls tend to be low frequency and “noisy” (makes animal sound bigger / more threatening)

−submissive/fearful/alarm calls tend to be high-frequency and tonal

1.High levels of background noise select for specific frequencies that are not “masked”

2.Echoes from hard objects in cluttered environments select for “simpler” signals

Receiver Psychology with Signals

3 Important Requirements

Factors that affect evolution of Signal Design:

6 Things

Costs of Grouping:

5 Things

• Food Compitition
• Disease
• Reproductive Interference
• Dominance Relationships
• Conspicuousness

Benefits of Grouping:

Evading Predators

Five ways that groups reduce predation risks

1. Shared vigilance
2. Confusion effect
3. Group defense

4. Dilution effect(statistical chance on being killed lowers in larger groups)
5. Selfish herd effect

Benefits of Grouping:

Cooperation

4 ways that groups cooperate

An individual’s total contribution of genes to the next generation.

Helper is helping those closely linked genetically.

Relatives share copies of the same genes.

rB > C

Where

r = Coefficient of Relatedness

B = # recipients that benefit

C = # direct offspring not produced

1.Cooperation by individuals other than parents in caring for offspring.

2.Overlapping generations in the colony.

3.Reproductive division of labor –mostly or wholly sterile worker castes.

Cooperation without altruism.

Happens when there is little incentive to cheat.

In Theory Non-kin Cooperation can be maintained by

_______ and _______.

Leks:

Hotspot Hypothesis

Leks:

Hotshot Hypothesis

Leks:

Female Preference Hypothesis

Males aggregate because females prefer larger groups of males (the shopping mall effect).

Leks:

Predator Avoidance Hypothesis