Topic 13 -Mating Systems

Question 1

3 disadvantages of sexual reproduction

Answer 1

only half of an individuals genes are passed on to the next gen

growth rate is half of that of asexual reproduction (takes 2 to make 1)

some unfavourable recombinations

Question 2

Gender biases in animals

typical pattern

Answer 2

males do the courting and females do the choosing

Question 3

male fitness is often dependent on acquiring

Answer 3

multiple mates

Question 4

female fitness is often dependent on access to

Answer 4

abundant resources

Question 5

Gender biases are a result of

Answer 5

unequal investment in gametes (Anisogamy)

Question 6

males fitness increases by

Answer 6

fertilizing multiple eggs

Question 7

females fitness increases by

Answer 7

continued investment in costly egg

also results in females having already invested more in gamete production to continue to invest in parental care

Question 8

secondary sex characteristics
males evolution driven by sexual selection imposed by limited female partners
2 things

Answer 8

traits to enhance attractiveness

traits to enhance competitive ability with other males

Question 9

traits to enhance attractiveness

Answer 9

hypothesized to display good genes and a healthy condition

inherit genes for impressive display
females inherit preference for display

Question 10

Traits to enhance competitive ability with other males (5)

Answer 10

impose dominance hierarchy
sneaky male strategy 
mate guarding 
sperm competition 
nuptial gifts

Question 11

Mating system

Answer 11

the number of partners that males and females have

can vary among species

includes aspects of parental care

Question 12

Polygyny

Answer 12

a single males takes on multiple mates

most common observed mating

Question 13

4 reasons for Polygyny

Answer 13

Female defense: females cluster together for predator defense or resource patches

resource defense: resources are clumped and male will control area that is attractive for females

Lek polygyny: male sets up and elaborate mating display (no resources involved)

Scramble competition: timing window for mating may be short, first come first serve

Question 14

Polyandry

Answer 14

single female takes multiple male mates

rare in nature, when something limits brood size of female

Question 15

Monogamy

Answer 15

a single pair bond between one male and female

common in fish and birds

when there is a risk female will take multiple mates in absence of mate guarding

when males offer up energetically costly support

Question 16

Promiscuity

Answer 16

females and males take multiple mates

result of coevolution of other mating systems between males and females

both sexes increase fitness by having multiple mates