11. Sexual selection II

Question 1

what three things do females need to consider before mating

Answer 1

1) getting the right species- hybrids are infertile
2) direct benefits- food, nesting sites
3) genetic quality

Question 2

give some examples of direct benefits

Answer 2

food, laying sites, parental care, protection from harrassment

Question 3

give some examples of good genetics

Answer 3

parasite resistance, longevity, sexiness

Question 4

how do Australian litona frogs determine the correct species

Answer 4

by listening to the call and differentiating them

Question 5

describe malte anderssons study

Answer 5

examined long tailed widow birds

• males have long tails but females do not suggesting a role in mate choice
• found females preferred longer tailed males over shorter ones

Question 6

who studied sedge warblers, what did they find

Answer 6

Clive Catchpole

those males with larger repertoire in there song tended to pair early

Question 7

what are the two principles for the evolution of elaborate traits

Answer 7

fishers runaway theory

Zahavi’s handicap principle

Question 8

what is runaway theory

Answer 8

females preference for traits should become genetically linked with the trait- greater reproductive success

Question 9

how do preferences arise (2)

Answer 9

1) natural selection benefit- faster runner or better flyer

2) sensory bias- perceived first over other males, eg louder call or obvious signal

Question 10

what is the handicap principle

Answer 10

long tails are expensive handicaps- put them at risk of predators as they are easily seen
-females prefer them because it signals the males ability to survive despite this

Question 11

how is the peacocks tail an example of handicap principle

Answer 11

females are choosy, prefer spotted tail that is symmetrical