sexual behaviour and reproduction

Question 1

what are the two types of sexual selection?

Answer 1

mate competition (intra-sexual)

mate choice/courtship (inter-sexual)

Question 2

why are females choosy?

Answer 2

Due to gamete size

Batemans’s principle (invest more energy and therefore females are a limiting resource)

parental investment (NUTRIENTS, GESTATION, LACTATION, DEFENDING)

Question 3

what are the benefits of mate choice?

Answer 3

direct benefits: avoidance of infected partners, good resources (nuptial gift) and can defend offspring

indirect benefits: good genes for offspring

Question 4

what is the sexy sons hypothesis (fisher, 1930)

Answer 4

displays selected to be attractive

attractive fathers with produce attractive sons

Question 5

what is the handicap principle (zahavi, 1975)

Answer 5

only successful individual can afford costly traits

this will be passed on

Question 6

how does mate choice occur?

Answer 6

1) locate mate
2) species recognition
3) assessment of mate
pick up on cues, traits

Question 7

how to locate a mate ..

Answer 7

sticklebacks = visual
moth = olfactory
green tree frog = acoustic
(weakly electric) fish = electric signal

Question 8

how does species recognition occur?

Answer 8

stickleback fish will follow, examine and look for when the species spawn to see whether they recognise them

Question 9

how to choose a partner…

Answer 9

preference for novel traits - finch

copy other’s choices (social) - gubby

preference for supernormal traits (extra long tail in widowbirds)

Look at multiple cues (looking for age and parasite resistance in green finch plumage)

Question 10

Developing a preference in mate choice

Answer 10

If there is no experience then preference is genetically fixed

experience such as sexual imprinting and learning can effect mate choice

Question 11

genetically fixed preference of malawi cichlids

Answer 11

there is a genetically predetermined sensory bias with produce female preference, this is due to opsin genes which favour certain colours

Question 12

impact of sexual imprinting on mate choice

Answer 12

cichilids fostered by a closely related ciccilid species have a mate preference for their foster mothers species

Question 13

impact of learned mate preference

Answer 13

zebra finches prefer songs that sounds like their fathers song

Question 14

brain size and sexual behaviour in guppy’s ..

Answer 14

larger brained guppy’s show preference for the colour guppy’s that signify being attractive

small brained guppy’s do not show this preference

Question 15

brain size and sexual behaviour in bowerbirds …

Answer 15

as the cerebellum volume increases the bowerbirds complexity of nest building increases

Question 16

brain size and sexual behaviour between bird species …

Answer 16

as relative brain weight increases across bird species there sexual displays (routines) become more complex

Question 17

are clever mates chosen?

Answer 17

those that are perceived as more attractive have a higher rate of learning (guppy experiment)

Question 18

summary of neuronal basis of sexual bahaviours

Answer 18

brain size courtship
(within and between species)

brain size mate choice

Question 19

how are hormones related to sexual behaviour

Answer 19

hormones = signalling molecules produced by glands to regulate bahviour

progesterone controls sex interest and sex attractiveness

testosterone controls sex interest and courtship

Question 20

the behavioural products of hormones ..

activation

Answer 20

japanese quail, as testosterone increases so do the number of mating attempts

Question 21

the behavioural products of hormones

synchronisation of reproductive physiology

Answer 21

when males and females first arrive and when they are building their nests they are most aggressive and then begin to turn into docile during young and post-nesting

Question 22

hormones and sexual behaviour ..

Answer 22

hormones influence behaviour (activation, synchronisation, mate choice)

behaviours influence hormones