B&B innate vs learned behaviour Flashcards
Has behaviour evolved?
Evolution of behaviour depends on the heritability of behviour Natural selection: 1) Variation between individuals 2) The variation affects survival 3) Variation is inherited Sexual selection: 1) Variation between individuals 2) Variation affects reproductive success 3) Variation is inherited
Describe the Blackcap warbler migration
Breeds central Europe
Traditional wintering area is in spain and portugal until the proportion of breeding population went to western migration orientation eg uk.
Evidence for genetically determined. 0%-12% in 30 years migrate this new route.
Coincidence with warmer UK winters
Evolutionary change because evidence its genetically determined
Is there a gene for migration?
Mueller et al 2011 examined 6 candidate genes influencing migration behaviour
Variation at one locus explained 2.6% of variation between populations in migration tendency
Not a hugely strong influence but still an influence but between 27% of migration restlessness within 2 different populations. This is a much stronger influence in a different population
How do genes influence behaviour?
eg bird migration
Hormonal changes
There are genes controlling corticosterone (stress)
Rate at which fat reserves are built up
(foraging activity, migratory fuelling rate and departure fuel load)
There are genes controlling melatonin
Influences diurnal/nocturnal cycles
(migratory restlessness, departure decisions, duration of migratory flights)
There are genes controlling orientation in relation to visual/magnetic cues
(migration route)
There are multiple genes influencing multiple traits
How do the songs of field crickets show traits are heritable?
Selection experiments
Sexual selection -ability to attract a mate
Playback experiments show that females (and parasitic flies) prefer a
high chirp rate
long chirp duration
loud chirps
So there is a sexual selection on song traits
Attract parasitic flies though which kill crickets so sexual selection is balanced by natural selection
There is a gene for calling rate in crickets
That means that there is heritable variation in calling rate
This does not mean that genes are the only determinant of calling rate or that an individual’s calling rate cannot vary.
Calling rate is also influenced by the environment such as…
Ambient temperature
Presence of females
“Satellite” males chirp more when there are no other males around
What do we mean by there being genes for behaviour?
A genetic difference giving rise to variation in behaviour
Does not mean there has to be 1 single gene determining the behaviour or that the behaviour is unaffected by the environment
eg dog behaviour
= breed traits (genes) + training (environment)
How can behaviours be strongly influenced by the selective environment?
Natural selection
Sexual selection
Artificial selection
eg selecting for tameness in silver foxes
There are pleiotropic effects on other traits, of selection for tame behaviour
eg floppy ears
curly tails
wagging tail
whining,licking
fur pigment
A lot of traits favoured by selection for tameness are traits associated with juvenile behaviour and morphology. Retain juvenile traits
Is human language genetic or environmental?
100% genetic and 100% environmental
Genes for language (anatomy of vocal tract, neural apparatus)
Environment (learning)
How do genetic differences lead to differences in behaviour?
Transcription products
Regulation of transcription
Protein synthesis
Hormonal control of cellular
/ organ / system processes
Describe genetic basis of social behaviour
E.g. storm petrels Hydrobatidae spp.
Differences in Major Histocompatability Complex (MHC) gene complex leading to differences in odour production
Odour-based mate choice for immune-system function
Studies by Alex McCubbin, Cardiff University
E.g. sweat bees Lasioglossum spp.
Access to nest burrows is granted only to closest relations
Genetic differences in odour production
Studies by Greenberg et al.
Describe environmental basis of social behaviour
E.g. honeybee queen development
All larvae fed briefly with “royal jelly”
Larvae fed for longer with royal jelly develop into queens
How is some behaviour modified through experience of similar circumstances?
Habituation – reduced response across repeated exposures to a stimulus
Neophobia – brief aversion to novel objects
Dietary wariness –prolonged aversion to novel food
Social learning
– changed behaviour in response to observing the behaviour of others
Cultural transmission
–transmission of behaviour within (& between) social networks
What are some primate tool use cultures?
Moss/leaf sponge
Ant/termite “fishing”
Honey scoops
Stone hammers
Sticks as weapons
