Sexual conflict and Sexual selection PO

Question 1

sexual reproduction involves

Answer 1

gamete formation (egg and sperm)

Question 2

Characteristics of a sperm?

Answer 2

small, unlimited and ‘cheap’ to produce

Question 3

Characteristics of an egg?

Answer 3

large, relatively scarce and cost a lot to produce

Question 4

sexual reproduction involving sperm and egg is called?

Answer 4

Anisogamous sexual reproduction

Question 5

What is there an asymmetry of between males and females when looking at rearing offspring?

Answer 5

Parental investment and Parental effort

Question 6

What is parental investment?

Answer 6

effort put into rearing an individual offspring

Question 7

What is parental effort? (PE)

Answer 7

effort put into rearing all offspring produced during lifetime

Question 8

What does the asymmetry between parenting roles lead to?

Answer 8

sexual conflict

Question 9

What do differential PE lead to?

Answer 9

differential ideal strategies to maximise reproductive success.

Question 10

Where male PE is lower… they should?

Answer 10

maximise reproductive success by ruthless promiscuity

Question 11

What are harems?

Answer 11

wives of a polygamous male

Question 12

Why should females be choosy and coy when choosing mate?

Answer 12

to offset high cost of reproduction

Question 13

What roles do females and males have when choosing mate?

Answer 13

Females will do choosing, males will compete for access to female

Question 14

What will females mainly invest in?

Answer 14

PE

Question 15

What will males mainly invest in?

Answer 15

ME = Mating effort - acquiring mates

Question 16

Define Monogamy

Answer 16

M and F form exclusive pair bond

Question 17

Define Polygyny

Answer 17

M mates with several Fs

Question 18

Define Polyandry

Answer 18

F mates with several Ms

Question 19

Polygyny + Polyandry =

Answer 19

Polygamy

Question 20

If PE is equal =

Answer 20

more equal ME

Question 21

If PE is unequal =

Answer 21

less equal ME

Question 22

What is sexual selection?

Answer 22

‘the decent of man and selection in relation to sex’

Question 23

Females being choosy and males being competitive for access to females leads to….

Answer 23

selection of traits solely concerned with increasing mating success

Question 24

Two types of sexual selection:

Answer 24

Intrasexual selection and Intersexual selection

Question 25

What is intrasexual selection?

Answer 25

Where Ms compete for access to Fs, those best equipped to win will pass on their genes to next generation.

Question 26

What can Intrasexual selection lead to?

Answer 26

Tusks, antlers, claws, large muscles and large teeth

Question 27

Intrasexual selection leads to ________, M becomes a _______

Answer 27

1. dimorphism | 2. fighting machine

Question 28

Example of effects of intrasexual selection?

Answer 28

Red deer stag, compete for Fs, strongest stags command largest harems, led to sexual dimorphism, M more bulky than F, M possesses antlers (employed in aggressive, interlocked fights)

Question 29

Example of intrasexual selection, after copulation?

Answer 29

Black winged damsel fly, F may mate with several Ms prior to laying eggs, M developed ability to remove existing sperm from F sperm storage organ, Ms penis has lateral horns and spines, scrubs out competitor's sperm prior to release of own sperm

Question 30

What is intersexual selection?

Answer 30

reluctant females will show preference to males who show clear evidence of material resources and/or 'better' genes.

Question 31

Example of material resources in intersexual selection?

Answer 31

Hanging flies, F hanging flies will mate with a M only if provides large insect to eat during copulation. Allowed duration of copulation is relative to insect size.

Question 32

Example of genetic benefits in intersexual selection?

Answer 32

genetic benefits may underlie development of elaborate adornments

Question 33

Case study on genetic benefits (Widow bird, Kenya)

Answer 33

M = sparrow sized with up to 50cm tail, F prefer M with longer tail, Andersson studied 36 M widow birds. 4 groups: shortened tail, elongated tail, control 1 (untouched) control 2(cut and repaired tail). Mating success measured as number of active nests in territory. Long tailed Ms did better than controls or short tailed.

Question 34

What is Fishers hypothesis of the 'runaway process'? (Widow bird case)

Answer 34

starts with preference for Ms with increased flying ability, get positive feedback between Fs, and longer tails. yet not optimal for flying purposes.

Question 35

What is Zahavi's handicap hypothesis?

Answer 35

Elaborate adornments= handicap in day to day survival. Demonstrated Ms ability to survive in spite of handicap.

Question 36

Only healthy animals will show fully developed secondary ______________ (include adornments)

Answer 36

sexual characteristics

Question 37

Adornments are a sign of?

Answer 37

sign of health

Question 38

intersexual selection not only leads to elaborate adornments , but also to ________ and ________

Answer 38

1. courtship displays | 2. rituals