Exam 1 - Case Studies

Question 1

Burrowing Behavior in Mice - Question

Answer 1

Question - how the burrowing behavior evolved from different sister species of mice

Question 2

Burrowing behavior in mice - methods

Answer 2

• placed 7 sister species of mice in chambers with sandy loam soil and let them dig for 48 hrs
• then removed the mice and filled the tunnels with foam to replicate the tunnels length & width

Question 3

burrowing behavior in mice - results

Answer 3

ancestral trait is absence of burrowing and complex burrowing is a derived trait
burrowing derived independently

Question 4

Zebrafish environment- question

Answer 4

does the variation in the zebrafish environment during development affect their aggression

Question 5

zebrafish behavior - methods

Answer 5

raised clutches of 12 eggs in 2 diff environments - oxygenated H2O(normal) and nitrogen H2O(stressful)
- tested for agression with a mirror
- recorded the fishes response to the mirror for 2 min and recorded the time they spent nipping/butting the mirror

Question 6

zebrafish behavior - results

Answer 6

hypoxic fish had more aggression in their testing chamber and vice versa for normoxic fish - fish most aggressive in their own rearing conditions

Question 7

Disruptive selection in spade foot toad tadpoles - question

Answer 7

is disruptive selection acting on the different morphs of spade foot toads?
- omnivores and carnivore morphs feed more efficiently than the intermediate morph
- omnivore and carnivore morphs have higher fitness than the intermediate morph

Question 8

disruptive selection in spadefoot toads - methods

Answer 8

Experiment 1 - to test the efficiency of the morphs to eat one food type - allowed one toad per pool….
- omnivores – eat plant material for 8 days and recorded the growth
- carnivores – with 10 fairy shrimp - recorded how long it took the morphs to capture/eat shrimp
Experiment 2 - test the overall fitness of morphs
- 500 individuals marked based on morph type (color injected under skin)
- after 8 days, 1,500 individuals collected and counted the number of colored individuals

Question 9

disruptive selection in spadefoot toads - results

Answer 9

Experiment 1 - found that feeding in specialized morphs was higher and they had higher fitness
Experiment 2 - found that intermediate morphs had lower chance of survival bc of lower recapture rate when compared to carnivore/omnivore morphs
- intermediate morphs were also smaller = lower fitness

Question 10

Frequency-dependent selection in slamanders - question

Answer 10

whether frequency - dependent selection as a result from bird predation maintains the polymorphism of dorsal or non dorsal stripe

Question 11

Frequency-dependent selection in slamanders - methods

Answer 11

made model salamanders out of clay with either a dorsal stripe or no dorsal stripe
- placed peanut under the model and placed them side by side in a leaf litter box
- placed the leaf litter box in a field near a woodlot
researcher counted survival if the model still had its peanut attached to it at the end of the day

Question 12

Frequency-dependent selection in slamanders - results

Answer 12

first six days - ratio of unstriped:striped was 5:45
next day was even numbers of morphs
next six days - ratio of unstriped:striped was 45:5
next day was even number of morphs
- determined that when morph was at low frequency, had higher survivorship
- rare always survived

Question 13

environmental effect on jumping spider personalities - questions

Answer 13

do adults show differences in exploratory behavior?
does the complexity of rearing environment alter the adults personality?

Question 14

environmental effect on jumping spider personalities - methods

Answer 14

spiders split into 3 groups
deprived, physically enriched, and socially enriched
researchers allowed the spiders to mature and they then placed them in an arena for 60 min to observe how they respond to new environment

Question 15

environmental effect on jumping spider personalities - results

Answer 15

found that there were significant differences in spider behavior based on their rearing conditions
- experiences alter the behavior of an adult

Question 16

directional selection of juvenile ornate tree lizards - question

Answer 16

what affect does body size have on speed and survivability of tree lizards?

Question 17

directional selection of juvenile ornate tree lizards - methods

Answer 17

45 lizards tested for 2 days on a 2m sand track
photocells recorded their movement
body size, mass and stride length was recorded
marked and released and studied for another 6 months

Question 18

directional selection of juvenile ornate tree lizards - results

Answer 18

larger, heavier more likely to survive - large directional selection on limb length (larger limbs - longer strides = faster speed)

Question 19

great tit exploratory behavior - question

Answer 19

is exploratory behavior heritable in the great tit?

Question 20

great tit exploratory behavior - methods

Answer 20

• using birds from 2 diff populations, researchers placed them in aviary with 5 artificial trees - they recorded the number of flights/hops birds took in first 2 min
• the fast and slow groups were split and were bred together for 4 generations

Question 21

great tit exploratory behavior - results

Answer 21

• the offspring resemble the parents behavior - positive correlation between exploratory score of the mother and offspring
• artificial selection on the exploratory behavior caused significant differences in the selected lines ( by 4th get, the exploratory scores were either 4x higher or 4x lower depending on the selected line)

Question 22

behavioral differences between wild-type and mutant-type fruit flies - question

Answer 22

why aren’t yellow fly forms common in nature? Was genetic variation associated with behavioral variation?

Question 23

behavioral differences between wild-type and mutant-type fruit flies - methods

Answer 23

created different lines of inbred flies with similar genomes EXCEPT for the yellow gene
conducted mating trials using both wild and mutant type males and recorded mating success/courtship behavior

Question 24

behavioral differences between wild-type and mutant-type fruit flies - results

Answer 24

wild-type males had higher mating success & mated sooner than yellow males
- yellow males showed less courtship behaviors

Question 25

the “guilty look” in dogs - question

Answer 25

do dogs experience guilt?

Question 26

the “guilty look” in dogs - methods

Answer 26

took 14 dogs owners
dogs exposed to treats, told not to eat it - O left the room
O was “told” wether or not they ate the treat (sometimes the dog did not eat it - O was lied to by experimenter)
O was told to scold dog if treat was “eaten”
dogs reactions were recorded

Question 27

the “guilty look” in dogs - results

Answer 27

found that wether or not if the dog ate the treat or not, they still displayed the guilty look when scolded
O behavior had an effect on dogs behavior

Question 28

social environment and gene expression in larval fruit flies - question

Answer 28

how could different social environments affect behavior?
- do flies have diff genes for male-male interactions and male-female interactions OR a set of socially responsive genes that express in all social interactions?