behavior, part 1
DESCRIPTION
Slides for discussion of The Living World, 7th edition chapter 37, adapted from a compilation by Amy.TRANSCRIPT
Behavior
What organisms do
37.1-8, 10-12
39.1-8, 10-12
Behavior is shaped by evolution, like physical traits
Behavior is also flexible enoughto change with the environment
Behavior is widespread
Proximate Cause
Genetic or physiological mechanismfor a behavior
Ultimate Cause
Evolutionary, adaptive cause for a behavior
Human taste and food choice
Proximate causesWhat regulates hunger cravings?
Ghrelin
a hormone that stimulates hungerproduced by cells in the stomach and pancreas
Ghre
lin leve
lTime of day
increases before meals and decreases after meals
Pleasure
Dopamine
Ultimate causes:Why did we evolve to like certain
foods?
Sodium (mg) 700 2300-6900
Late Paleolithic Contemporary American
Amount of Sodium in Diet
Proximate cause
Hormones trigger pleasure in our brain
when eating certain foods
Ultimate causeHumans evolved to prefer salty food
in a low sodium environment
Nature vs Nurture
Nature:- Instinctive/Innate Behaviors- Behavioral Genetics
Fixed Action Pattern fixed response to a stimulus
KonradLorenz
Stimulus: egg outside of nest
Fixed Action Pattern: roll into nest
Stimulus: egg objectoutside of nest
Fixed Action Pattern: roll into nest
Most behavioris not fixed, but can still have a genetic basis
fosB gene controls maternal care in mice
Mutant fosB allelle Normal fosB allele
38
Twin Studies
Studies of identical twins show strange behavioral coincidences:
“Springer and Lewis found they had each married and divorced a woman named Linda and remarried a Betty. They shared interests in mechanical drawing and carpentry; their favorite school subject had been math, their least favorite, spelling. They both had sons whom one named James Alan and the other named James Allan. And they both owned dogs which they named Toy.”
University of Minnesota twin study, Bouchard et al
Studies of identical twins show strange behavioral coincidences:
“Oskar was brought up Catholic in Germany and joined the Hitler Youth. Jack was raised a Jew and lived for a time in Israel. Yet they had similar speech and thought patterns, similar gaits, a taste for spicy foods and common peculiarities such as flushing the toilet before they used it.”
MAOA “warrior” gene
MonoamineOxidase A
Enzyme breaks down neurotransmittersin the brain (including adrenaline)
People with an allele for low MAOA activity tend to respond more aggressively when provoked
Nurture:Learning
Learning:from simple to complex
Habituationrepeated stimuli produce weaker responses
Sensitizationrepeated stimuli produce stronger responses
Classical Conditioning
associating behavior with a new stimuli
Operant Conditioning
Associating behaviorwith a reward or punishment
Imprinting
Filial Imprinting:offspring form innate social attachments
Cognition
Can non-human animals think?
Naturevs Nurture
Naturevs andNurture
White-crowned sparrow (WCS)
• Normal song
• No song
• Wrong song
In lab experiments, newly hatched WCS maleswere played:
Song sparrow song
Peter Marler’s research
• Normal song: sang correct song
• No song: sang poorly developed version of WCS song
• Wrong song: sang poorly developed version of WCS song
In lab experiments, newly hatched WCS maleswere played:
MAOA “warrior” genePeople with low MAOA activitywho experienced a traumatic event as a childwere more likely to exhibit antisocial, violent behavior as adults
People with low MAOA activity who did not experience a traumatic eventwere not any more likely to be violent than control groups