Lecture 7. Animal Diversity: Reproductive Strategies

Question 1

What is the purpose of reproduction ?

Answer 1

1. Increase fitness

2. Get as many genes as possible into the next generation

Question 2

What are the various challenges animals face when reproducing ?

Answer 2

1. Choosing and finding a mate
2. Ensuring fertilisation success
3. Ensuring offspring survives to reproduce

Question 3

What are the two types of interactions ?

Answer 3

1. Intraspecific

2. Interspecific

Question 4

What are intraspecific interactions ?

Answer 4

Interactions within species

Question 5

What are some examples of intraspecific interactions ?

Answer 5

1. Group living
2. Competition
3. Reproduction
4. Sexual conflict

Question 6

What are interspecific interactions ?

Answer 6

Interactions between species

Question 7

What are some examples of interspecific species ?

Answer 7

1. Predation and herbivory
2. Competition
3. Mutualism
4. Parasitism and disease
5. Pollination

Question 8

What is an example of external fertilisation ?

Answer 8

Marine species releasing sperm and eggs into the water

Question 9

What is the advantage of external fertilisation ?

Answer 9

1. Mass spawning
2. Energetically cheap
3. Many offspring
4. Overwhelms predators

Question 10

What is the disadvantage of external fertilisation ?

Answer 10

No mate choice

Question 11

What are the different types of mate systems ?

Answer 11

1. Monogamy
2. Polygyny
3. Polyandry
4. Promiscuity

Question 12

What is monogamy ?

Answer 12

One male one female

Question 13

What is polygyny ?

Answer 13

One male, multiple females

Question 14

What is polyandry ?

Answer 14

One female, multiple males

Question 15

What is promiscuity ?

Answer 15

Multiple males and multiple females

Question 16

What is sexual selection a form of ?

Answer 16

Natural selection

Question 17

What do traits selected in natural selection influence ?

Answer 17

Survival

Question 18

What do traits selected for in natural selection influence ?

Answer 18

Mating success

Question 19

What is intersexual selection ?

Answer 19

Selection for traits that increase attractiveness to females

Question 20

What do birds of paradise display ?

Answer 20

Their brightly coloured feathers

Question 21

How do manikin birds attract mates ?

Answer 21

Perform a dance

Question 22

How do bowerbirds attract a female ?

Answer 22

Build bowers

Question 23

What is intrasexual selection ?

Answer 23

Selection for traits that increase success in fighting

Question 24

What do mates use in intrasexual selection and why ?

Answer 24

Ornaments to indicate their strength this reduces the need for costly unnecessary battles

Question 25

How did male choice evolve ?

Answer 25

1. Good gene hypothesis | 2. Sexy sons hypothesis

Question 26

What is the good genes hypothesis ?

Answer 26

Traits used in display and are energetically costly so give the female an honest signal about how good the males is at acquiring food or resisting disease.

Question 27

What is the sexy sons hypothesis ?

Answer 27

Traits used to fight or display will be passed on to the females sons, increasing their likelihood of mating in the future

Question 28

What can sexual selection drive ?

Answer 28

Speciation

Question 29

How does one ensure fertilisation ?

Answer 29

Get the sperm as close to the egg as possible often using an intromittent organ

Question 30

How does fertilisation in a cephalopds ?

Answer 30

Hectocotylus - one of the male arms has different tissues which allows it to become rigid with grooves down its arm. This arm then enters the female through a hole in its mantle

Question 31

What is the intromittent organ called in squamates ?

Answer 31

Hemipene

Question 32

What are some mechanisms that males have to ensure their sperm fertilises the female ?

Answer 32

1. Male guarding | 2. Remove sperm of other males

Question 33

How do males damselflies ensure their sperm reaches the female ?

Answer 33

Wheel position

Question 34

How do male lovebugs ensure their sperm reaches the female ?

Answer 34

Copulate for several days

Question 35

How do golden orb web spiders ensure their sperm reaches the female ?

Answer 35

The copulatory palp breaks off during mating acting as a post copulatory plug

Question 36

How do females invest more energy in offspring than males ?

Answer 36

1. Eggs are bigger than sperm 2. Incubating eggs 3. Internal development of sperm 4. Parental care 5. Producing milk

Question 37

How do males maximise their fitness ?

Answer 37

Have as many offspring as possible and hope some survive

Question 38

How do females maximise their fitness ?

Answer 38

To have few, high quality offspring which survive

Question 39

What do drosophila so to prevent intersexual conflict ?

Answer 39

Use chemicals that kill the sperm of other males. But this may also damage the female

Question 40

How do bed bugs combat intersexual conflict ?

Answer 40

The males have needle like structures for traumatic insemination

Question 41

How do birds usually reproduce ?

Answer 41

Cloacal kiss

Question 42

What is interesting about the birds penis /

Answer 42

1. Usually inverted inside the male 2. Rapid eversion during mating 3. Anticlockwise spiral

Question 43

What does more male-male competition result in ?

Answer 43

Longer duck penis

Question 44

What is interesting about duck vaginas ?

Answer 44

1. They are clockwise spiral shaped 2. When the female want to mate it relaxes its vagina so it straightens resulting in fertilisation 3. In unwanted mating attempts the vagina remains spiraled and sperm very rarely reach the egg