Transcript Why do we do the things we do?

Chapter 39.3 – 39.6 ~ Animal Behavior
Why do we do the things we do?
• Ethology - study of animal behavior
• Behavior – everything an animal does
and how it does it
-response to environmental stimulus
2 Types:
Innate – inherited or developmentally fixed
Learned – develop during animal’s lifetime
Why study behavior?
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Part of phenotype
Acted upon by natural selection
- effects reproductive success, genetic
fitness, survival rate
Supernormal stimulus
What questions do we ask?
Causes:
•proximate~ physiological & genetic mechanisms of
behavior IMMEDIATE “How & What” of behavior
 What triggers singing?
•ultimate~ evolutionary significance of behavior – survivial,
reproduction, adaption LONG TERM “Why” of behavior
 Why does he sing?
What, How, and Why of courtship behavior?
Pioneers of Ethology
1973 Nobel Prize: Konrad Lorenz, Niko Tinbergen, Karl von Frisch
Studied instinctual
behaviors “Imprinting”
Originated “proximate” &
“ultimate” causations.
Studied “supernormal
stimulus”
Studied sensory
perception in honey bees
“waggle dance”
Innate vs. Learned – a closer look
Innate behaviors
• Automatic/Built – in
• Despite different
environments, all
individuals exhibit the
behavior
• Triggered by stimulus
Learned behaviors
• Modified by experience
• Variable
• Triggered by a stimulus
Innate Behaviors
• Fixed Action Patterns (FAP):
sequence of acts; unchangeable; carried
to completion
(Dog circling bed, eyebrow flash humans
and other primates, egg retrieval in
birds, male stickleback aggression & red)
• Circadian Rhythm – Daily behavior
cycles, light/dark response
• Migration – complex navigation via
sun, stars, earth’s magnetic field
• Imprinting – limited learning social
attachments at ‘critical period’
• Directed Movements –
TAXIS: specific, directed movement
(cockroaches scattering away from light,
drosophila crawling to top of container)
KINESIS: random, undirected (pillbugs wandering to find moist side of choice chamber)
Learned Behavior
LEARNING: change in behavior as result of experience
• HABITUATION~ loss of responsiveness to stimuli; learn NOT to respond
- simple learning (annoying sounds, lights, etc)
• ASSOCIATIVE LEARNING:
•classical conditioning~ Pavlov’s dogs behavior associated neutral stimulus with
significant stimulus. Works with involuntary behavior.
•operant conditioning (trial and error)~ “Skinner’s box” behavior associated with
reward or punishment. Works with voluntary behavior.
Behaviors in Action
2 types:
Innate/Instinctive (genetic not learned):
Fixed Action Pattern
Baby Joey in Pouch
Interaction of innate & learned:
Duck & Dog - Imprinting
Learned (result of experience):
Classical Conditioning “The Office”
Operant Conditioning “The Big Bang”
Causes of each? Proximate? Ultimate?
Learned behavior II:
Social behavior
• Interactions between individuals.
-Develop as evolutionary adaptations
• Agonistic behavior~ contest behavior
determining access to resources; submissive and
threatening rituals usually no harm done
• Dominance hierarchy~ social ranking/linear
“pecking order” that establishes an individual’s place
in social group. Division of labor makes cooperation
more efficient and effective.
• Altruistic behavior~ unconscientiously selfless
behavior that may be disadvantageous to individual but
beneficial others.
??? Cats play patty cake
Reconciling altruism & natural selection
• Natural selection works on populations
NOT individuals
• Altruism may hurt individual but helps
population
• Kin selection-increase probability of survival of
relatives at expense of individual
Why do Belding ground squirrels make alarm call? Why females more than males?
Lab 12: Fruit Fly Behavior
1. Construct choice chamber from 2 plastic
1 L soda bottles & toss in 10 – 20 fruit
flies. Count flies inside. Wait 5 minutes.
2. Expose specific areas to different
treatments of your choice & record #
flies on each side over period of time
3. Graph results and perform chi square
analysis.
11
Experimental Design 101
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State Hypothesis
Identify All Variables
Identify a Sample Organism
Identify the control(s)
Explain how you will to measure data
Provide expected data
Interpret your data (with a sentence & graph)
Understand importance of repetition & sample
size.