Sexual Selection

Question 1

What is sexual selection?

Answer 1

a subset of natural selection that affects traits related to mate competition and attractiveness

Question 2

What are the main processes of sexual selection?

Answer 2

Intrasexual selection: Competition among the same sex for mates.

Intersexual selection: Mate choice based on attractiveness.

Question 3

What is an example of Intrasexual selection ?

Answer 3

fighting in speckled wood butterflies

Question 4

Why does sexual selection occur?

Answer 4

It arises from the need for reproductive success through mate acquisition.

Question 5

What are examples of Intersexual selection?

Answer 5

extravagant ornaments and displays, typically in males/ assessment and discrimination (mate choice), typically in females

Question 6

What is an example of Intra-combined with intersexual selection?

Answer 6

traits used in both intrasexual (male-male) and intersexual interactions
E.g.)antlers in some species–> signal of power and strength in males and admired by females -If in combat however, the horns would easily break off

Question 7

What is parental investment?

Answer 7

The investment in gametes and care of offspring that affects reproductive rates.

Question 8

Give an example of asymmetry of in sexes

Answer 8

Differing interest of males and females. Both want many offspring but go about it in different ways
E.g.) Ostrich–> many eggs in different location or less eggs but more nurtured

Question 9

What is the potential reproductive rate (PRR)?

Answer 9

The maximum number of offspring an individual can produce based on sex and parental care.

Question 10

Describe female-only care in parental systems.

Answer 10

Males have a higher PRR, while females invest in offspring care.

Question 11

Describe male-only care in parental systems

Answer 11

Females have a higher PRR, as males invest in offspring care.

Question 12

What happens in lifetime monogamy with biparental care?

Answer 12

PRRs of males and females become interdependent, leading to sexual monomorphism.

Question 13

What is the Bateman Principle?

Answer 13

In species without parental care, male reproductive success increases with the number of mates, while female success levels off.

Question 14

Why is there a plateau in the Bateman Principle graph?

Answer 14

investment in gametes for females is much more expensive

Question 16

How do species with parental care differ in PRR?

Answer 16

PRR depends on gamete size and the amount of parental care provided by each sex.

Question 17

Give an example of a species with reversed parental roles.

Answer 17

Seahorses, where males become pregnant and females compete for mates.

Question 18

What is a key characteristic of species with male parental care?

Answer 18

Females often exhibit brighter coloration and compete for mates.

Question 19

What is intrasexual selection?

Answer 19

Competition, often male-male, for access to mates.

Question 20

What is intersexual selection?

Answer 20

It influences the investment strategies of males and females, affecting their PRRs.

Question 21

How does parental care affect sexual selection?

Answer 21

It influences the investment strategies of males and females, affecting their PRRs

Question 22

What is sexual dimorphism?

Answer 22

Differences in size or appearance between males and females of the same species.

Question 23

How does the presence of parental care influence female mate choice?

Answer 23

Females may become choosier to ensure high-quality offspring.

Question 24

What is the relationship between gamete size and parental care?

Answer 24

Larger gametes (females) often lead to greater parental investment.

Question 25

Why might females be choosy in mate selection?

Answer 25

To maximize the quality of their offspring through selective mating.

Question 26

What is the significance of ornamentation in males?

Answer 26

It often plays a role in attracting females during intersexual selection

Question 27

What does the term "sexual monomorphism" refer to?

Answer 27

Similarity in appearance between male and female individuals, often due to equal parental investment.

Question 28

How do male reproductive strategies differ from female strategies?

Answer 28

Males often focus on quantity (number of mates), while females focus on quality (mate selection).

Question 29

Name a species where males display extravagant traits for mate attraction

Answer 29

Peafowl (peacocks) are known for their elaborate tail feathers.

Question 30

What role does competition play in intrasexual selection?

Answer 30

It drives the evolution of traits that enhance fighting ability or dominance.

Question 31

How can parental care influence evolutionary outcomes?

Answer 31

It can shape mating systems and reproductive strategies in a species.

Question 32

Describe the reproductive strategy of the Dotterel.

Answer 32

Males incubate eggs, while females are often more ornamented and compete for mates.

Question 33

What is the difference between macrogametes and microgametes?

Answer 33

Macrogametes are larger (females), while microgametes are smaller (males).

Question 34

How does the concept of PRR apply to humans?

Answer 34

Humans exhibit an intermediate PRR between female-only and biparental care systems

Question 35

What is the evolutionary significance of mate choice?

Answer 35

It can lead to the development of traits that enhance reproductive success and survival

Question 36

How do species without parental care demonstrate the Bateman Principle?

Answer 36

Males gain fitness by increasing mate number, while females reach a saturation point.