Sexual Selection

Question 0

What is the cost of recombination?

Answer 0

This causes the break up of successful genotypes and the recombination of their elements

Question 1

What are the twofold costs of sex?

Answer 1

Sexual

Asexual

Question 2

What is the cost of mating?

Answer 2

In all species which sexually reproduce much time and energy is invested into securing mates

Question 3

What use is sex?

Answer 3

• sex must have advantages

- these advantages must be something to do with the recombination process

Question 4

What is the red queen theory?

Answer 4

Antagonistic pairs of species such as predator and prey or parasite and host react to each ofthers ongoing evolution by evolving counterploys

Question 5

What is the red queen theory cont?

Answer 5

• disease is the biggest threat to most species

- sexual recombination may provide defence against rapidly evolving pathogens

Question 6

What defines male and female?

Answer 6

• gamete size

- anisogamy

Question 7

What is anisogamy?

Answer 7

The fundamental sex difference

Question 8

What did Darwin do in 1871?

Answer 8

Theory on male traits

Question 9

What is natural selection?

Answer 9

Survival of the fittest

Question 10

What is sexual selection?

Answer 10

Survival of the sexiest

Question 11

What does sexual selection focus on?

Answer 11

It’s attention on the selective consequences of sexual interactions within a species

Question 12

What does natural selection focus on?

Answer 12

Operates in the context of other environmental factors (such as climate, disease, adaptations for good finding etc)

Question 13

Who studied fertility of male and female fruit flies?

Answer 13

Bateman 1948

Question 14

What did Bateman find from his experienment with fruit flies?

Answer 14

• variance in male reproductive success is much greater than female
• male reproductive success depends upon number of mates

Question 15

What is batsmans principle?

Answer 15

The sex which invests more in the young becomes a resource for which other members of the less parental sex compete

Question 16

Sexual selection and sex differences

Answer 16

• males compete for access to females in the majority of species
• this competition leads to sex differences in both morphology and behaviour
• as a generalisation the bigger the difference in parental investment between sexes the more different sexes are

Question 17

There are two types of sperm competition what are they?

Answer 17

• pre- colulatory

- post- copulatory

Question 18

Sperm competition and body size in primates

Answer 18

• testis size and body size dimorphism linked to mating system in primates
• multi male and multi female groups (chimps) provide a lot of opportunity for sperm competition

Question 19

What is female choice?

Answer 19

• female May prefer males with secondary sexual traits

- no widely accepted as a major force in evolution.

Question 20

What is runaway selection (fisher)?

Answer 20

• some variation in females preference for a male trait

- sons of these females inherit the trait daughters inherit the preference

Question 21

What are the direct and indirect benefits of runway selection?

Answer 21

• females can gain directly from mating

Question 22

What is the handicap principle?

Answer 22

• Zahavi 1975

Secondary sexual characteristics may be attractive because they are detrimental to survival