Lecture 21

Question 1

When does courtship begin?

Answer 1

two potential conspecifics of the opposite sex are in close proximity

Question 2

What are 2 main functions of courtship?

Answer 2

Mate assessment

Mate synchronization

Question 3

Why is the range of courtship signals short?

Answer 3

Reduce eavesdropping by predators or mate competitors

Keep nest hidden

Question 4

________ signals are particularly effective

Answer 4

Tactile

Question 5

Directional information is well coded by visual displays. What does this mean?

Answer 5

Direct attention toward certain individuals.

Color patches and displays

Question 6

Courtship signals are what?

Answer 6

lower in amplitude but higher in duty-cycle than attraction signals.

Question 7

Courtship signals are derived from what?

Answer 7

reproductive intention movements

Question 8

What are some reproductive intention movements?

Answer 8

Mimic nest construction
Mate provisioning
Nest material manipulation

Question 9

What are the 4 main types of models of mate choice?

Answer 9

Direct benefits
Good genes
Runaway selection
Sensory exploitation

Question 10

Describe the direct benefits model.

Answer 10

 Males vary in a non-heritable phenotypic trait that indicates a direct benefit to the female and her offspring

Question 11

Give an example of direct benefits model?

Answer 11

High song rates rates in birds linked to amount of resources in territory

Question 12

Describe nuptial gifts?

Answer 12

Usually food, given to potential mates during courtship.

Question 13

Given an example of nuptial gifts?

Answer 13

 Female scorpion flies alter amount of time spent mating in direct proportion to size of nuptial gift

Question 14

What do male scorpion flies do?

Answer 14

Developed aggressive
foraging behaviors
 Will steal prey items from each other
 Males will mimic receptive females to steal prey items from other males

Question 15

Why are costly and conspicuous male traits the target of female choice?

Answer 15

Such traits indicate some aspect of male quality. Provide offspring with higher survivorship

Question 16

What are indicator traits?

Answer 16

traits females use to make selection decisions (good genes model)

Question 17

How do female pronghorn antelopes select mates?

Answer 17

Based on ability to protect harem. Males with largest harems are presumably more successful.

Question 18

Byers tracked survivorship of offspring based on what?

Answer 18

Mother’s harem size.

Question 19

What was the findings in the Byers study?

Answer 19

Offspring from ‘attractive’ males had higher survival

rates than offspring from other males

Question 20

 Genetic models of this process are based on

coevolution of three characteristics:

Answer 20

Male indicator trait
Female preference for the trait
extra one idk

Question 21

Why should honest indicator traits be costly to produce?

Answer 21

More costly traits are harder to ‘fake’ and increase reliability
 Low quality males cannot support the cost of these traits

Question 22

The male trait (in the handicap model) and female preference are limited due to survivorship. Why?

Answer 22

Males w/o trait and its cost have higher fitness

Question 23

Describe the Hamilton-Zuk hypothesis?

Answer 23

-Females select traits that indicate parasite resistance
-Body coloration is reliably
linked to endoparasite
infection
-Endoparasites aren’t visible but can have impact on outward expressed traits

Question 24

What is major histocompatibility complex (MHC)?

Answer 24

set of genes that improves disease resistance

Question 25

MHC is the most variable set of genes (no 2 ppl have matching MHC). Why?

Answer 25

Variability must be a result of preference for individuals with NON-matching MHC  Selection is based on olfactory cues

Question 26

What was the study Wedekind did?

Answer 26

Tested human preference for MHC variability |  Men wore the same shirt for two nights; women were asked to select the most ‘attractive’ shirt

Question 27

What were the findings of the Wedekind Study?

Answer 27

 Women reliably selected shirts from males with the most dissimilar MHC

Question 28

What study did Milinski do?

Answer 28

Tested cues used by female sticklebacks to | detect MHC quality

Question 29

Sticklebacks range in MHC alleles from ___ to _____.

Answer 29

2 to 8

Question 30

Individuals with more alleles have what?

Answer 30

Strong disease resistance

Question 31

What were the findings of the Milinski study?

Answer 31

Females reliably preferred males with the largest | number of MHC alleles

Question 32

In runaway selection, a relationship exists between what?

Answer 32

alleles that code for a | male trait and female preference for that specific trait

Question 33

What happens when the preference/trait association is set in motion?

Answer 33

The effect will become exaggerated over generations  Males will develop an amplified version of the originally preferred trait  Females will apply stronger selection pressures for the expressed trait

Question 34

Female stalk eye flies prefer males with _______ eye stalks.

Answer 34

longer

Question 35

What two test conditions were created in the stalk eye experiment?

Answer 35

Males with the longest eye stalks were allowed to breed  Males with the shortest eye stalks were allowed to breed  Females were selected randomly for the two treatments

Question 36

What were the results in the long stalk eye condition?

Answer 36

Resulting offspring | had increasingly long eye stalks and the converse was true in the short eye-stalk condition

Question 37

When females of the subsequent generation of short eye stalks were given free choice of mates, what happened?

Answer 37

they selected males | from their experimental condition (preference has to exist in females)

Question 38

Cluttonbrock studies male-male competition in red deer. What are the findings?

Answer 38

 Male stags compete to maintain harems  23% of harem holders show signs of fighting injury  6% are permanently injured

Question 39

Male red deer use what to help judge fighting ability?

Answer 39

bouts of roaring

Question 40

When is roaring seen?

Answer 40

almost exclusively during mating season.

Question 41

When do roaring rates increase?

Answer 41

When male competitors approach