Sexual Selection

Question 1

Darwin

Answer 1

not a struggle for existence but a competition between males for possession of females
male-male intrasexual
female choice intersexual

Question 2

Why are females choosy (Bateman)

Answer 2

Female fitness is limited by fewer large gametes so females are choosy.

Question 3

Direct benefits

Answer 3

1. access to resources
2. food
3. sufficient sperm to fertilise eggs
4. reduce the risk of predation

Question 4

Indirect benefits

Answer 4

1. good genes for offspring
2. offspring inherit favoured traits

Question 5

Combat

Answer 5

eg male iguanas attempt to copulate with many females at different times.
1. stake out territories and fight other males
2. head pushing, biting

Question 6

Sperm competition

Answer 6

1. sperms race to eggs from different males that females mate with
2. large ejaculates help
   eg damselflies scoup out previous sperm left by other males

Question 7

Infanticide

Answer 7

eg. lion males kill cubs so females can breed again with them
detrimental to female reproductive success

Question 8

Hangingfly

Answer 8

1. when it catches an insect, hangs from a twig and releases pheromones to attract females
2. female approaches and the longer it takes to eat the prey, the longer the copulation
3. if females eats in less than 20 minutes, moves to another male to copulate