Lecture 3

Question 1

What is Genotype?

Answer 1

Genetic makeup of an individual

Question 2

What is Phenotype?

Answer 2

External expression of genotype
Physical and behavioural phenotypes
Modified by environment

Question 3

What is the equation for heritability and what does heritability mean?

Answer 3

H^2 = Genetic variation / Phenotypic variation
OR
H^2 = Genetic variation / (genetic + Environmental variation)

Heritability is the proportion of phenotypic variation due to genetic causes.
H^2 = 0-1
H^2 = 1 means that 100% of the phenotypic variation is due to genetics vise versa.

Question 4

What evidence is there that behaviour is inherited/intrinsic?

Answer 4

Herding behaviour, a baby that knows how to walk right after birth and can find the udder on its own to eat.
Bird songs, courtship displays, nest building in birds & sows

Question 5

Individual behavioural differences are what?

Answer 5

Inherited

Question 6

What 7 breed Canine breed groups do we select?

Answer 6

Sporting
Hounds
Working
Terrier
Toy
Non-sporting
Herding

Question 7

What is cross breeding?

Answer 7

Breeding two closely related species
Offspring show a mix of behaviours

Question 8

What is divergent selection?

Answer 8

One genetic line
Selected for ‘high’ and ‘low’ traits
Breed multiple generations
‘high’ to ‘high’, ‘low’ to ‘low’
Select each generation for ‘high’ and ‘low’
performers

Question 9

What do genes control?

Answer 9

Genes code for a specific protein which then performs certain functions such as hormones, neurotransmitters, receptors.

Question 10

What changes to the CNS occurs with genes?

Answer 10

During development- expression of neurotoxic factors create neural pathways

Protein synthesis- enzymes regulate synthesis of hormones and neurotransmitters

Formation of cell receptors- modulate sensitivity

Question 11

What is the epigenetic effect?

Answer 11

Methyl groups can stop gene expression even if the gene is there (like a light switch)
Upregulation, downregulation

Question 12

What are the 4 phenotypes in ‘Undertaking’ behaviour in bees?

Answer 12

Uncap and remove
Uncap but not remove
Not uncap but will remove
Will neither uncap nor remove

Question 13

What conclusion did Scott and Fuller (1965) get when they studied the behaviour of several breeds of dogs?

Answer 13

All Basenjis were ‘wild’
All Cocker Spaniels were ‘tame’
f1: All Basenji X C. Spaniel crosses were ‘wild’
f2: 1/4 of f2 generation were ‘tame’
Single gene effect
‘Wild’ trait is dominant; ‘tame’ is
recessive

Question 14

What is Tameness associated with?

Answer 14

Coat colour

Question 15

What is Nature VS. Nurture?

Answer 15

Nature: ‘born that way’
it’s all in your genes

    ‘genetic determinism’, inevitability
  
    Plato, Rene Descartes (1600’s) Views 
    used to justify racism, ‘Social 
    Darwinism’

Nurture: ‘made that way’
product of environment/experience

    John Locke, BF Skinner (1900’s) All 
    behaviour is learned, can be 
    controlled By Punishment and 
    Reinforcement

Question 16

What results did the ‘Bright’ and ‘Dull’ rats- divergent selection study find?

Answer 16

1st Conclusion: intelligence is genetic, because this was a controlled system it ignores environment

Later experiments: rats tested in different rearing environments: Restricted, Normal, Enriched
Bright & Dull: both performed well in enriched environment and Both did poorly
in restricted environment.

Gene x Environment interaction: ‘Dull’ rats were more sensitive to environment. Did poorly in Normal environment

Question 17

Behavioural traits will evolve if…

Answer 17

1) There is variation in behaviour between
individuals
2) The behaviour is heritable
3) The behaviour provides a selective
advantage, increased ‘fitness’, i.e.,
number of offspring

Question 18

What is the game of life?

Answer 18

To survive

Question 19

How can the evolution of behaviour be studied?

Answer 19

1) Examine closely related species
2) Phylogenetic tree: compare innate
behaviours e.g., courting rituals, calls,
nesting behaviour
◼ Each species has specific patterns of
behaviour
◼ “Fixed action patterns”

Question 20

What is Fixed action patterns (FAP)?

Answer 20

FAP is a complex action/behaviour

Can be performed without any previous experience and Performance improves with experience
examples: goose rolling egg, dog making bed, dog burying bone, chick hatching from egg

Question 21

What is sexual selection?

Answer 21

Fitness = Reproduction
Reproduction involves sex…
Sex involves behaviour…

Sexual behaviour… played important role in evolution of physical phenotypes- sexual differences/ dimorphism

Specialized behaviours: ritualized courtship behaviour & plumage

Question 22

What is the Handicap theory in sexual selection?

Answer 22

Handicap theory —> energy cost

Healthier males: Produce more dramatic plumage

Outcompete others in displays and vocalizations

More attractive = more mates & greater
reproductive fitness

Question 23

Reproductive fitness in wild animals is by?

Answer 23

Darwinian selection

Question 24

Reproductive fitness in domestic animals depends on…?

Answer 24

‘reproductive fitness’ depends on selection by humans

Question 25

What Behavioural changes are seen with
domestication?

Answer 25

Reduced fear response

Increased social tolerance

Most behaviours are largely unchanged
◼ Nesting in poultry and pigs
◼ Feral animals- survive & reproduce; show all natural behaviours

Domestication is flexible- any trait can be
selected for But- selection can only change ‘so much’

Question 26

Deliberate behaviour selection was first
seen in what?

Answer 26

companion animals

Question 27

Is there one ‘optimal behaviour’ for each
species and behaviour?

Answer 27

Balance of costs vs benefits
Optimal territory size: has greatest benefit for least cost
There is not one optimal behaviour, different behaviours provide different
benefits at different times

Question 28

Within a social species…..

Answer 28

All animals can’t be dominant

Adapt to multiple roles within a group

Diversity enhances group stability/cohesion

Over time…
◼ Different strategies are beneficial
◼ Depending on changes to environment
◼ population density, resources

Question 29

How has domestication influenced behaviour?

Answer 29

It changes the amount of time the animal performs its natural behaviour