What is behavioural genetics
examines the role of genetics in behaviour
how do genes influence behaviour
Innate behaviour
programmed response to stimuli
- can be reflexes, or simple/complex behaviour patterns
- genetically programmed
- intrinsic- develop even in isolation
- stereotypic
- inflexible
learned behaviour
modified by previous experience
-non heritable
Evidence for genetic effects
- naturally occurring differences between related species
- collection of nesting materials by love birds - within species
- fruit fly feeding behaviour - artificial selection for particular behaviours
- maternal aggression - manipulation of gene expression
- sex differences in behaviour altered by Bad gene knockout
- controls neuronal cell death, results in elimination of sex differences in brain
Environment vs genes
environment can influence development and expression of behaviours
-genes don’t guarantee a particular behavioural outcome
How do genes influence behaviour
- regulate developmental processes during embryology and later ontogeny (sexual differentiation with SRY gene)
- ongoing coding for synthesis of proteins important to behaviour (metabolism, hormones, neurotransmitters)
Domestication how does it occur?
genetic changes -artificial selection -inbreeding -genetic drift Environmental effects -developmental and epigenetic effects of management and housing practice
Conscious vs inadvertent artificial selection
conscious- intentional manipulation of particular traits
inadvertant- accidental manipulation
-personal biases influence selection of breeding stock
-selection for one trait influences another
Key differences in behaviour of domesticated animals
neoteny relaxation of feeding behaviour reduction in fear reduction in aggression to conspecifics relaxation of sexual behaviour
Genetic relationships can be challenging to determine for behaviour
- multiple genes control complex behaviours
- limitations of behaviours tests
- environmental conditions difficult to control
English cocker spaniels coat colour and behaviours
solid colours more aggressive than white spotted
reds and golden more aggressive than blacks
labradors
chocolate- fewer behaviour problems, lower aggression
black- intermediate
yellow- higher aggression
Possible mechanisms to explain coat colour and behaviour
- changes in pigmentation may influence sensory organs
- melanins share biochemical pathways with catecholamines - dopamine
- gene for coat colour may be close to genes for behaviour
Breed difference- emotional reactivity
-excitability,activity level, barking, snapping
varies across studies-partly due to differences in identification
Exploratory behaviours/fearfulness
-sociability and curiosity are highest in labs, golden and lowest in GSD, poodles and Belgian sheperds
Breed differences for trainability
10 common breeds
Not only breed effects
-differences between show and field lines
-interactions with sex and neuter status
Canine breed differences- abnormal behaviour
- circling - bull terriers, German shepards
- digging- rotties
- anal checking- schnauzers
- flan sucking- dobermans
Molecular genetics in dogs
- SNP markers for breed stereotypes -herding, pointing, boldness, trainability
- Genes related to serotonin and dopamine for aggression and anxiety
- cadherin 2 related to compulsive sucking dobermans
Friendliness towards people and willingness to explore novel objects related to?
sire temperment
Breed profiles for aggression/sensitivity and vivaciousness
aggression-
-low- rag doll, main coone
mild- himalayan, persian
high- Abyssinian, Russian blue,somali
Poor maternal behaviour in?
blue-eyed white cats
