AB2 Week 2: Learning & Nature vs. Nurture (Types of Learning (Spatial…
AB2 Week 2: Learning & Nature vs. Nurture
: the adaptive modification of behaviour based on
: Relatively permanent change in behaviour or potential for behaviour resulting from
(Drickhamer et al.)
: all aspects of the environment surrounding an organism from conception
of learning: brain space
Ability to learn depends on availability of neurons related to that function
By learning, those new neural pathways cannot be used for other functions
E.g. Song of
: east coast birds have 40 learned songs, west coast birds have 100 songs. Song control tissue of WCBs is 25% larger than that of ECBs
Is learning an adaptation?
Can learn from experiences relevant to survival, obtaining food, etc.
NS has to act on the heritable portion of a behaviour, so if an adaptation is learned, NS has to act on the genetically determined component of the behaviour
of things that
learning capacity is limited to learning species songs and not all sounds. Learning any and all sounds would not guarantee better reproductive success, but learning a species' song better would
Things that enhance reproductive success
Where it starts to differentiate... once learned, the behaviour is modified as the experience is repeated
Types of Learning
learned to associate the sound of a bell ringing with food
Conditioned response: salivation
Skinner's Rat (
learned to associate pulling a level with food
Conditioned response: pressing lever
Technique most often used in learning (?)
Trial and error learning
Learning that some behaviour results in predictable consequences
Doesn't work for
Success of conditioning depends on pre-existing biases in the brain
are rapidly conditioned for food aversions via taste and smell of toxic food but cannot associate sounds with toxic food
Adaptation relevant for generalist feeders
Prediction: food specialist rats that have never encountered toxic food will be less able to learn taste aversion
Adaptation: taste aversion
Cannot learn to avoid novel fluid associated with nausea
rapidly learn to avoid novel food associated with nausea
Observation: Individuals visually observe others, learn what the appropriate behaviour is, and repeat it
- learn to seek bread by observing other ducks
Imitation: individuals copy the behaviour of others
in close proximity
imitate food washing behaviour
imitate environmental sounds
Spatial Learning: storing and remembering spatial information // mapping of resting areas, safe areas, and food locations.
: learn the location of food and their hive, successfully navigate daily between these two places
: males learn location of and avoid mimetic orchids that look and smell somewhat like female wasps
: have different spatial learning capabilities
are not habitual food cachers but are better at performing complex tasks
Clark's Nutcrackers and Pinyon Jays
store seeds in hidden cache sites, remember the location of these sites, and retrieve seeds later. They have a larger hippocampus that other Corvids but are worse at performing complex tasks.
have similar ranging behaviour in both sexes and similar spatial memory abilities
have wide-ranging males with better spatial memory than females of the same species
: Males perform better in tests of navigational skills in mazes than females while females score higher in language skills
Hippocampus is used for spacial memory in
: brooding females are parasitic. They find nests of other birds, return later, and lay their own eggs in them. Males play no role after copulation. Females have a larger hippocampus than males.
Imprinting: Process in which early social interactions contribute to learning what (species) constitute an appropriate social (sexual partner)
: goslings imprinted on ethologist Konrad Lorenz
Blue Tit-Great Tit
: nestling Great Tit males that were cross-fostered into Blue Tit nests sought Blue Tit females as mate
Code breaking (?): Replicating the releaser required to trigger a FAP - exploitation of another animals' instinctive behavioural tendencies
: parasitic chick that produces releasers adapted to exploit the host adults' FAP
Chick crams its' beak into the warbler mouth and takes the food, causing the warbler chicks to starve
Nature vs. Nurture
Nature: genetically determined trait
The Bell Curve by Herrnstein and Murray
Claimed that human racial differences in IQ are mostly determined by genetic causes
15pt average difference in IQ between blacks and whites in America, with substantial heritability of IQ in family lines within each group - but no control for environmental effects
ILJ's hypothetical example 1
Large sample of human twins raised apart, all going to the same primary school and attend the same class, are given a test. The scores are highly variable except for the twins score alike.
Tested ability is genetically determined
ILJ's hypothetical example 2
Large sample of human twins raised apart, all going to the same school. They are separated early on into different groups to prepare for grade 6 test. Variability in grade 6 test scores depended on the class.
Tested ability is environmentally determined
ILJ's hypothetical example 3
Smart twins did poorly in poor environments, dumb twins did well in rich environment
Neither nature nor nurture alone determined test performance
Performance is based on an interaction between genes and environment
Single gene effects on behaviour
Oxt gene in mice
- allows M to remember F that they have had close encounters with. Oxt mutants cannot remember F that they have had close encounters with. Oxt mutants also tend to be permiscuous
Behavioural polymorphism in D. melanogaster
- a single gene controls the activity of the fruit fly; each fruit fly is either a rover or a sitter.
FosB gene in mice
has a single allele for FosB that mediates parental cuddling of offspring. If they are not homozygous then females ignore their pups
Neural Control of Behaviour
Nervous System generates responses that are appropriate reactions
NS selects the preferred neural control mechanisms that have been successful
Begging behaviour of
Herring Gull chicks
to strangers shows a established neural network
Chicks knock their beaks against their parents', inducing nausea in the parents and causing them to expel the contents of their stomach.
Triggered by a red spot on the parents' beak. If the spot is covered, the chicks do not knock.
Experiment: A mount w/ a mock beal having the red dot elicits almost the same response as a real parent. A parent with the red spot covered elicits very little knocking behaviour.
: red dot on bill
Fixed action pattern
(instinctive behavioural pattern): chick begging
Innate releasing mechanism
: chicks brain
super normal stimulus:
Nurture: environmentally influenced trait
: the bee phenotype includes behavioural phases during its' life span (cleaning phase, nursing phase, and foraging phase)
2000+ genes are varied during these phases and interact with environmental inputs such as feeding, social interactions, and hormones.
breeding experiments - birds breed true for their migration orientation direction.
Some fly to Britain (bird feeders)
New "race" of birds
Most fly SW to winter in West Africa
Eastern Europe: all fly SE to winter in East Africa
Complex behaviour w/ genetic control
Interactive Theory of Development: genes and the environment interact to produce variation - no trait is entirely environmentally determined or genetically determined