BIO220 Lecture 3 Flashcards Preview

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Flashcards in BIO220 Lecture 3 Deck (50):
1

Mating behaviour of satin bowerbird

Males build bowers pre-mating season, and decorate with blue/yellow objects to attract females. Mate her while she is distracted with the decorations.

2

Mating behaviour of sage grouse

Leks: female come in to inspect the males, and pick one that she wants

3

How is the variance in sage grouse mating?

High variance in mating success in males (1 or 2 males get all the females)

4

Female choice

A female trait that biases the mating success of males towards the preferred type

5

Other words for female choice

mating bias, female preference

6

What categories of traits are the females looking for?

- Visual stimulation
- Tactile stimulation
- Acoustical stimulation
- Olfactory stimulation

7

Examples of organisms that use visual stimulation

Scorpionfly
Barn swallow
Long-tailed widowbird
Satin bower bird
Cichlid fish
Field cricket
Jungle fowl

8

Examples of organisms that use tactile stimulation

Sierra dome spider

9

Examples of organisms that use acoustical stimulation

Field cricket
Woodhouse's toad
Great reed warbler
Tungara frog

10

Examples of organisms that use olfactory stimulation

Mouse
Cockroach
Moth

11

Why was the tail manipulation experiment done, and on what species?

To make sure the trait we think is being selected for by females is actually being selected for.
Done in widow birds.

12

What were the groups that were in the tail manipulation experiment

Natural (N)
Reduced (R)
Elongated (L)
Sham surgery (S)

13

What is the purpose of sham surgery?

Tail length not changed, but some manipulation is done (control group)

14

What was found by the tail manipulation experiment?

L > N = S > R
Females do prefer males with longer tails

15

What peacock trait do females prefer?

More eyespots on tail

16

Two animals which use visual stimulation to attract mates

1. Widow birds
2. Peacocks

17

How do tungara frogs attract mates?

Complex calls (whine & chucks);
Whines attract females, and number of chucks is what makes one male better than the other.

18

Why don't all tungara frogs have more complex calls?

Bats are attracted to whines of males too, and they are more likely to get eaten if they have more chucks

19

Two problems of female choice

1. Why are male elaborations common?
2. Why do females prefer certain traits?

20

Why are male elaborations common?

Females prefer them, so there is selection for elaboration

21

Why do females prefer certain traits in males?

1. Direct benefit to female for selecting such traits (can produce more offspring)
2. Indirect benefits to females (through offspring)

22

Direct benefit hypothesis implies that females select males w/ certain traits b/c

She's actually selecting for resources (PI) that the male has. The trait is just an indicator of PI.

23

PI

Parental investment

24

How do female mormon crickets pick mates?

Pick those with bigger spermataphores. Male will stick it on her, and while she eats the protein, the sperm will fertilize her.

25

Spermataphores

Sperm attached to a protein glob. Bigger = more protein for females to nourish herself with.

26

How do hanging flies pick mates?

Male kills prey, and displays to attract female with food. Females pick bigger offering. While she eats the food, male fertilizes her.

27

Why might bigger prey displays be beneficial to male and female hanging flies?

Females: more food
Males: have longer time to fertilize while female is eating = more sperm transferred

28

What do females look for as indicators of PI?

- Territory quality
- Parental care
- Defense
- Lack of parasites (STIs)

29

Indirect benefit hypothesis implies that females select males w/ certain traits b/c

They have better genes so offspring will be better (fitness)

30

When is indirect benefit hypothesis applicable?

- Only thing male gives female is sperm
- Female want to improve offspring quality, not quantity

31

How to test indirect benefit hypothesis?

Female identifies preferred male trait. Mate her to ones with best trait and worst trait. Examine offspring.

32

how are sex roles defined?

Resource investment in the offspring

33

Examples of high male PI?

- Giant water bugs
- Pipefish
- Katydids
- Spotted sand piper
- Plovers

34

Pipefish male reproductive success limited by...

size of their brood pouch

35

Pipefish female reproductive success limited by...

access to males' brood pouch

36

Mating system of pipefish

Females compete and are sexually selected for by the males

37

What do male pipefish look for?

Larger females (more eggs) & large fold

38

Katydid mating system (normal)

Males transfer spermataphores to female

39

Katydid mating system (low resources)

Females need male for spermataphores, and males limited by the resources to make spermataphores.

Males become the limiting factor.
Females will be sexually selected.

40

What changes when food is scarce for katydids?

- Male calls decrease
- Females mate more
- Male mate choice increases
- Female competition increases

41

MHC

Major histocompatibility complex

42

What does MHC do?

Code for antigen recognition system of the immune system

43

HLA

Loci that code for antigen recognition (immune response)

44

MHC in humans is...

HLA

45

What kind of MHC is good?

Ones with lots of genetic variation -> defend against more pathogens

46

Why do mice choose mates based on MHC?

- Avoid inbreeding
- Increase genetic diversity at MHC loci

47

Do mice choose mates based on MHC?

Yes; mate choice based on odours that correspond with differences at MHC loci

48

Are humans affected by odours that correspond with HLA?

Yes

49

What were the results of the odour study in humans?

- Intensity of odours similar between different HLA and same HLA group
- Women prefer those with different HLA

50

How does birth control affect how attractive scents are to women?

BC makes women think she is pregnant.
Might prefer those with same HLA = offspring and family who can take care of her.