Genetic Basis for Behaviour

Question 1

What are some of the ways to identify the genetic basis of behaviour?

Answer 1

Study naive youngsters

Cross-breeding

Comparison of relatives

Knock out gene experiments

Artificial selection experiments

Question 2

What did the tongue flicking experiment in garter snakes show?

Answer 2

Proved there was a genetic component to diet preference

BUT does not tell us what genes are involved and how many

Question 3

What was the Rover and Sitter experiment in Drosophila larvae?

Answer 3

Crossed sitter males with rover females

Recorded the distance travelled for food in their offspring

More were rovers so must be the dominant gene

When offspring were bred, there was a 3:1 ratio of rovers to sitters

Question 4

Are monozygotic or dizygotic twins more similar in behaviour?

Answer 4

Monozygotic

Monozygotic twins rasie separately are still more similar then dizygotic twins raised together

Question 5

What knock out experiments did they use to study behaviour in mice?

Answer 5

Normally, female mouse keeps pups together under her and if the pup moves away she will gather them back up

Inactivated the fosB gene in the mutant mouse

She does not keep pups under her or gather them back up if they move away

Question 6

How do we test that genetics can change depending on if the behaviour they code for can help an organism survive (evolution)?

Answer 6

Artificial selection experiments

Question 7

What was the artificial selection experiment carried out in mice?

Answer 7

Different mice carry different amounts of cotton (for bedding)

Bred large cotton gatherers together, bred small cotton gatherers together and bred large and small together randomly (control)

All offspring raised the same to make a fair test

Bred the offspring in the same pattern (large gatherer to large gatherer etc)

Repeated 15 times

Large gatherers bred together collected large amounts of cotton, control gathered a middle amount and small gatherers collected small amounts

So behavioural differences can be caused by genetics

Question 8

How is genetic variation maintained in behaviour?

Answer 8

If members of a species live in different local environments under different conditions they may experience different local selection pressures

This allows different behavioural phenotypes to evolve

Question 9

Where in Finland had a higher rate of twins and why?

Answer 9

Islands as they had more predictable food unlike the mainland