Sexual Selection

Question 1

What is parthenogenesis?

Answer 1

Only female species.

Question 2

What is the Bateman principle?

Answer 2

Females tend to limit male reproductive success.

Question 3

What is the result of the bateman principle? Why?

Answer 3

More variability in male reproductive success than in female reproductive success due to male-male competition.

Question 4

What is intersexual selection?

Answer 4

Selection for traits in one sex that attracts the other sex.

Question 5

Is sexual selection greater in monogamous or polygamous species?

Answer 5

Polygamous species.

Question 6

What is intrasexual selection?

Answer 6

Selection for the ability of one sex, often males, to compete with each other for access to the other sex, often females.

Question 7

What are the two main categories of intrasexual selection behaviors?

Answer 7

Precopulation and postcopulation.

Question 8

What are four examples of precopulation intrasexual selection?

Answer 8

1. Aggression. 2. Dominance. 3. Interference. 4. Cuckoldry

Question 9

What is an example of postcopulation intrasexual selection?

Answer 9

Sperm competition.

Question 10

What are two types of alternative mating strategies?

Answer 10

1. Conditional strategies. 2. Heritable strategies.

Question 11

What is a conditional alternative mating strategy?

Answer 11

An inherited mechanism that gives an individual the ability to alter its behavior adaptively based on the conditions it encounters.

Question 12

What is a heritable alternative mating strategy?

Answer 12

Variation in morphology and/or behavior is shaped by genetic differences.

Question 13

What two types of strategies can a male adapt for postcopulatory sexual selection?

Answer 13

1. Reduce the chances that a second male’s sperm is used (first male). 2. Reduce the chances that the first male’s sperm is used (second male adaptations).

Question 14

What are three examples of a first male’s postcopulatory adaptation?

Answer 14

1. Mate guarding. 2. Anti-aphrodisiacs. 3. Mating plugs.

Question 15

What kind of adaptation is infanticide?

Answer 15

Indirect interference.

Question 16

What is the bruce effect?

Answer 16

Spontaneous abortions when a new male is encountered.

Question 17

What are three reasons why females would be choosy?

Answer 17

1. Resources. 2. Parental care. 3. Genetic benefits.

Question 18

What is the healthy mate hypothesis?

Answer 18

Females choose traits that show a healthy male in order to avoid contagions or parasites.

Question 19

What is the MHC gene?

Answer 19

Gene associated with immune system variability.

Question 20

What is the Runaway selection hypothesis?

Answer 20

“Sexy son hypothesis” Inherit traits that made them sexually attractive.

Question 21

What is the Chase-away selection hypothesis?

Answer 21

Exploitative of pre-existing sensory biases - females derive no benefits by being choosy.

Question 22

What is symmetry theory? What might it indicate?

Answer 22

Many organisms prefer the most symmetrical mates. Might indicate co-adapted gene complexes that work well together during development.

Question 23

Those with fluctuating asymmetry show what?

Answer 23

Lack of genetic immunity from diseases during development.

Question 24

When is sex role reversal more common (2)?

Answer 24

1. In monogamous species. 2. Species where the male invests more in offspring.

Question 25

What is plasticity in female choice?

Answer 25

Females are less choosy when predators are around.