Lecture 10- Genes and behaviour

Question 1

‘breeder’s equation’

Answer 1

R = h2S
R- expected response to selection
h2- heritability
S- selection coefficient

Question 2

why is understanding variance important to the study of behaviour

Answer 2

need to understand variance to look at selection, which is important in the evolution of behaviour (obvs)

Question 3

how can you partition phenotypic variance

Answer 3

genetic variance and residual variance- aka the leftover

Question 4

how are heritability estimates calculated

Answer 4

either genetic variance/phenotypic variance (known as ‘broad-sense heritability’) or additive genetic variance- variance independent of interactions-/phenotypic variance (known as narrow-sense heritability)

Question 5

how you can split up genetic variance

Answer 5

additive- independent of background
dominance- interaction between alleles
epistatic- interactions between loci

Question 6

how heritable do behavioural traits tend to be

Answer 6

not very- possibly more influence from the environment?

Question 7

example of how gene conservation can be tested

Answer 7

using a large effect, single locus gene generally
e.g. rover vs sitter Drosophila- difference in a protein kinase protein

Question 8

QTL

Answer 8

quantitative trait loci- statistical linkage of phenotypic and genomic data

Question 9

example of a study using QTL

Answer 9

mouse burrowing- looking at different extents of burrowing, can calculate how much of this variation is associated with genetic diversity at different positions- found linkage with 3 genetic positions

Question 10

GWAS

Answer 10

genome-wide association study- looking at whole genomes, or many genetic markers, to ask how variation at all of the points may affect behaviour

Question 11

GWAS example

Answer 11

often used in humans, as there are a lot of samples available
Drosophila- many associations with aggressive behaviour

Question 12

pedigree-based methods

Answer 12

using breeding records to determine the origins of behaviour, pedigree diagrams to help determine the origins of behaviours

Question 13

selection experiments

Answer 13

repeating the same experiments on multiple generations, e.g. by taking birds into capticity and breeding from birds which are fast or slow at an activity

Question 14

some challenges introduced by environmental variation

Answer 14

can be hard to determine the origin of a specific trait
genes and culture can interact, making estimates fuzzy

Question 15

issues with behavioural genetics

Answer 15

non-experimental
often very strong cultural factors which affect behaviour
often focussed on very complex human phenotypes