UNIT 5 DAY 2 - Feisty Females

Question 1

When males are scarce, sexual selection can favour female adaptations —> Darwin’s 3 classes

Answer 1

1. When adult males “more beautiful or conspicuous” than females because males compete or females choose
2. When adult females “more beautiful or conspicuous” than males because females compete or males choose
3. When adult males resembles adult females

Question 2

Examples from Darwin’s 3 classes

Answer 2

1. Most abundant in nature (widowbirds and sticklebacks)
2. Jacanas, both genders have territories but females are more fierce and compete more
3. Blue-footed boobies, both display condition to mate, both parents share responsibilities

Question 3

Successful females, whose territories can encompass as many as 4 female territories

Answer 3

Polyandrous

Question 4

When parental invest,meant increases and abundance of egg/sperm decreases

Answer 4

Sexual selection on opposite gender strengthened

Question 5

Precopulatory sexual selection

Answer 5

• males compete
• male-male competition yields selection on features of male bodies (size, weapons) that allow them to win contents for access to females
• females choose
• female choice yields selection on features of male bodies (ornaments, dance, song) that appeal to female sensory bias or provide direct benefits or good genes

Question 6

Postcopulatory sexual selection

Answer 6

• males compete
• sperm competition yields selection on features of sperm (numbers, speed, longevity) that allow them to win competition to fertilise eggs
• females choose
• cryptic female choice yields selection on features of sperm that appeal to female sensory bias or provide direct benefits or good genes

Question 7

When do pre- and post- copulatory selection occur

Answer 7

Occurs after sperm are released

Question 8

Sperm competition

Answer 8

Sperm injected into female reproductive tract (more than 1 sperm) —> achieve fertilisation

Question 9

Cryptic female choice

Answer 9

Females control which sperm they allow to reach their eggs —> happens out of sight
—> eg. Insects have spermatheca that allows them to control when and which sperm are released to fertilise eggs

Question 10

What traits are favoured by sperm competition

Answer 10

• increased sperm number
• increased sperm speed
• increased sperm longevity

Question 11

Sperm number

Answer 11

All else being equal, the male who emits the most sperm with fertilise the most eggs

Question 12

Speed

Answer 12

If the sperm that reaches an egg are the ones most likely to fertilise it, sperm speed might outweigh sperm number

Question 13

Longevity

Answer 13

If sperm must endure long waits before they can reach the eggs, the sperm longevity might matter the most

Question 14

Parental males

Answer 14

Defend nests against other males

Question 15

Sneaker males

Answer 15

Strategy blast out sperm into nest with eggs

Question 16

Bluegills

Answer 16

• large testes, large bodies, mimics female submission to gain access to nest

Question 17

Female hierarchy

Answer 17

• high status means you get to breed
• low status regulates you to babysitting

Question 18

Female-female competition

Answer 18

• compete for resources to nurture their offspring, gives natural, as well as, sexual selection, a role in shaping female-female competition

Question 19

Meerkats

Answer 19

• dominant female and male procure all offspring
• dominant female prevents subordinate females from breeding by killing any offspring that manage to bear and by evicting the, when become old enough to threaten rule —> dominance also increased success of female offspring

Question 20

Dung beetles

Answer 20

• horn males: fight access to females, females fight for food for their offspring

Question 21

Sexual selection only favours traits related to breeding opportunity, natural selection shapes all traits that increase reproductive success

Answer 21

• “sex selects les rigorous, as a result isn’t death, but fewer offspring”, Darwins fault, reproductive success more important to species than survivors

Question 22

Clutton-brock et al - meerkats

Answer 22

• live in groups of 2-30 in arid South Africa, groups have dominant females —> oldest and heaviest

Question 23

Are the subordinate females able to breed?

Answer 23

• subordinate females are physiologically capable of breeding but they aren’t allowed too

Question 24

What are the effects of the presence/a sense of unrelated males on subordinate breeding?

Answer 24

• many subordinate females live in groups that contain no males unrelated dap them
• these animals show lower levels of fecal oestrogen are less likely to breed than are subordinates living in groups including unrelated males
• subordinates living in groups without unrelated males commonly mate with roving males from other groups and are clearly capable of breeding although dominate females may more easily restrict their access to females

Question 25

What is “limited control” of subordinate reproduction?

Answer 25

Limited control model: inability of a individual group member to successfully take over reproduction despite their best effort
Limited control = subordinate breeding

Question 26

what has effect on subordinates breeding

Answer 26

• rainfall
• weight
• age
• presence of unrelated male
• generation

Question 27

How do dominant females control the reproduction of subordinates

Answer 27

They kill their own grandchildren or nieces

Question 28

For three-spinned sticklebacks, which parent provides care of eggs and young

Answer 28

Male

Question 29

How do females judge male quality

Answer 29

Intensity of red throat colour

Question 30

When females display more exaggerated traits because females can compete

Answer 30

Males choose

Question 31

Blue footed boobies find bright blue-green feet so attractive

Answer 31

Because of carotenoid-based indicator

Question 32

Spermatheca

Answer 32

Store sperm

Question 33

First to attempt to rehabilitate Darwins theory of sexual selection by female choice

Answer 33

Ronald Fisher

Question 34

Cooperative breeding

Answer 34

Helpers per pup increases trait