Chapter 7 Flashcards
(112 cards)
1
Q
What kind of reproductive behavior do male satin bowerbirds exhibit? (2)
A
- male satin bowerbirds build a bower
- bower is a place for males to do courtship displays
2
Q
How do female bowerbirds exhibit reproductive behavior? (4)
A
- females visit bowers to inspect males
- after inspecting, builds her own nest
- after second round of inspections, she observes full ritual of several males
- enters a bower of chosen male
- later flies off, incubates and cares young by herself
3
Q
How do males differ in mating?
A
male courts several females during breeding season
4
Q
What are male bowerbird costs (4)?
A
- time and effort making bower
- gathering decorations
- defending bowers
- destroying bowers
5
Q
What is sexual selection?
A
if reproductive advantage means the individual will achieve higher reproductive success (having gaudy ornamentation but gets their bowers attacked/ being predated), traits will persist
6
Q
What should natural selection eliminate in bowerbirds?
A
natural selection will eliminate oblivious males while courting females/ bearing gaudy ornamentations
7
Q
What should we expect between males and bowers? (4)
A
- expect male mating success to be correlated with bower feature
- ex- skill which bower was made/ decorated (ex- number of blue feathers)
- females tend to be calmer at well-constructed bowers, leading to mating
- males mating success translates to genetic success
8
Q
Why might good builders be favorable? (4)
A
- healthier
- less likely to infect mates with disease
- resistant sperm genes
- study shows better builders to have fewer mites
- those with plenty food may have more developed brain, and can build better
- correlation between bower complexity and size of cerebellum
- cognitive ability was correlated with male nesting success
9
Q
Why does breeding seasons differ?
A
male breeding success is variable in different breeding seasons because females mate with only one male
10
Q
Why are female bowers choosy? (2)
A
- females are more likely to spend time foraging, building a nest, and caring for young than looking for mates
- reproductive success depends on quality of partner/ ability to make and care for young than the number of males she mates with
11
Q
What do male bowers devote their time?
A
males devote time building, guarding, or attacking bowers
12
Q
How do bowerbirds exhibit sexual differences theory?
A
males try to mate with multiple females, while females are content with a few carefully chosen males
13
Q
Why can males mate with multiple females? (3)
A
- males produce plenty small sperm and females produce few large eggs
- competition for males to fertilize eggs
- sperm carries only DNA and energy for flagellum
14
Q
How do male and female reproductive success differ?
A
- males reproductive success
- how many reproductive partners
- female reproductive success
- limited by number of eggs produced and energy to incubate and care for offspring
15
Q
why are females likely to invest time and energy caring for offspring than males?
A
- putting resources into fertilized eggs increases chance that offspring will survive and reproduce
- cost: removes time and energy in making more offspring
16
Q
What is the parental game/ parental investment?
A
- time and energy and risks taken by parent to protect offspring
- cost- reducing future reproductive opportunity
17
Q
why are females are more likely to derive a net benefit from parental care compared to males? (3)
A
- offsprings are likely to carry her genes, while paternity is less certain
- females can be inseminated by multiple males
- males have less incentive to be parental, as it pays him more to mate with several females
18
Q
What are four examples of parental investment?
A
- male frogs carrying tadpoles on back
- male katydid producing edible spermatophore for female
- eared grebe letting offspring ride on back
- fireflies producing edible spermatophore
19
Q
What does a different ratio of operational sex lead to?
A
- evolution of behavioral differences between sexes
- ex- parental care, size and number of gametes
20
Q
What can lead to a higher ratio of sexually active females?
A
males can make larger investments or engage in other activities
21
Q
Why might males make additional contribution to female? (2)
A
may benefit mate or offspring
if they don’t, they may not be able to fertilize
22
Q
WHat might happen if there is a female-biased sex ratio?
A
female competition for mates, and careful mate choice by male
23
Q
How do empid flies exhibit female-biased sex ratio?
A
- males hunt for prey and provide a nuptial gift
- with a gift, he can choose between females
- females displays bright colors or swelled legs
24
Q
How do pipefish and sea horse exhibit female-biased sex ratio?
A
- males provide a brood pouch for eggs
- pregnant males provide nutrients and O2 to eggs
- females can make enough eggs to fill two pouches
- females compete for the chance to give eggs to parental males
- males give up chances to feed and grow while brooding
- males in labs prefer to feed than breed
- when males choose females, they choose larger individuals with ornamentation
25
How do mormon crickets exhibit female-biased sex ratio?
- males transfers edible spermatophore to female
- females can produce more eggs with the nutrients
- spermatophore can make up 25% of male body mass, and may prevent additional mating
- females can produce several egg clutches
- must find multiple males to fertilize
26
How do kawanaphila katydid exhibit changing sex ratio?
- when katydid has only pollen-poor kangaroo paw flowers
- male provides expensive spermatophore to female
- more choosy males and competitive females
- when pollen rich trees are in bloom
- males can produce spermatophores more quickly
- sex ratio becomes male biased
- males compete for choosy females
27
What should we predict of sex ratio changes over a season?
if operational sex ratio changes over a breeding season, sex role differences predicts that sexual tactics of sexes should change too
28
Why can't males mate with optimal amounts of females (2)?
- deals with competing males
- deal with choosy mates
29
What might selection favor in competitive males? (2)
sexual selection for fighting prowess > larger body size
ornamentation or weaponry
30
Why might being dominant be beneficial in a hierarchy? (2)
- top male only has to move towards to a lowe rank to make it submissive
- if cost of attaining status is great, higher rank should have higher reproductive success
31
How do savanna baboons fight for heriarchy?
- males of low and high status had an equal chance of copulation
- timing was important
- dominant males copulated more with females that had recently ovulated
- better chance at monopolizing fertile females
32
Why might dominance in baboons not be beneficial?
- subordinate males can increase chance of mating
- can be friends with females and protect young
- females can then seek them
- subordinate males can band together and force a dominant male to give up a female
33
How do marine iguanas exhibit a conditionals trategy?
- larger males can dislodge smaller mounted males before they can fertilize a female
- small males can release sperm in advance
- if interrupted, they still have a chance to fertilize
- larger males still have a higher payoff
34
How do Horned scarab beetles exhibit conditional strategies?
- small males lose fights with males with larger horns
- as a larvae, those that don’t develop fast will shift investment from horns to producing testes
- small males will sneak into larger male burrows and try to copulate with a female using huge amount of sperm
- can swamp the larger male sperm
- larger males cannot have large testes and horns
35
What do alternate strategies allow for?
disadvantaged individuals to use a tactic that provides a payoff otherwise impossible if they used dominant individual tactic
36
How do horseshoe crabs exhibit conditional strategies?
- males can either grasp females, or crows and copulate females (satellite)
- graspers fertilize more eggs
- satellite males have at least some chance of reproductive success, not possible if they tried to attach
37
What mating tactics do male Panorpa scorpionflies exhibit?
-
- defend dead insects that attract receptive females
- secrete nutritionally rich saliva on leaves to attract females
- offer nothing, but grab and force a female to copulate
38
How did experiments show the hierarchy of Panorpa scorpionflies?
- largest male monopolized the 2 dead crickets
- medium-sized males did the saliva tactic, but could not compete for the cricket
- small males couldn’t produce enough spit, so had to do the force tactic
39
What did these tactics mean/ how were they evolved/ how do males select which tactic to do?
- these tactics were behavioral strategies based on social standing
- these tactics are environmentally caused/ not genetically caused
- males should use tactic with highest reproductive sucess
- males should switch to a higher yield tactic if social conditions permit
40
What happens if large male scorpionflies are removed (2)?
- medium sized males claimed cricket
- small males stopped force tactic and claimed leave with spit
41
What strategies do ruff sandpipers have?
- territorial independents
- subordinate satellites that join an independent on his territory
- have different plumage
- can mate when territorial male is not paying attention
- female mimics
- rare
- territorial males have less aggression
- large testes to swamp other male’s sperm
42
What kind of strategies do ruff males have?
hereditary, not conditional. since it can be passed down
43
What reproductive strategies do marine isopods have?
- males come in different sizes with its own behavioral phenotype
- large/ alpha
- lives in sponges
- blocks females into sponges
- can fight with other alphas
- medium/ beta
- pretends to be females if encountered by an alpha
- can coexist with alphas and sneak copulation
- small/ gamma
- avoids alpha
- sneaks copulation with females
44
What should we expect in marine isopods if they are distinct strategies (2)?
- it must differ due to genetics
- mean reproductive success should be equal
45
What should we expect if the marine isopod strategies was the same conditional strategy (2)?
- behavioral differences are due to developmental causes/ environmental differences, not genetic
- mean reproductive success doesn’t have to be equal
46
What was seen in experiments of strategies for marine isopods?
- different morphotypes and behavior types are hereditary
- reproductive success depends on how many rival males and females lived in the same sponge
- alpha did better if one female existed
- betas did better if multiple females existed
- gammas did better than other is other combination
- however, each strategy did not have a statistically different reproductive result
- this means that they are three distinct strategies, not a conditional strategy
47
What is sperm competition? (2)
- competition for fertilization success
- reproductive competition goes beyond obtaining a mate
48
How do sunfish exhibit sperm competition?
- territorial males
- ejaculates more and faster sperm
- small sneakers
- fertilizes a higher number of eggs when ejaculated along side territorial males
- can be due to being able to fertilize closer to the egg mass
- medium female mimics
49
How do blue-winged damselfies exhibit sperm competition?
- males try to win sperm war by removing rival gametes from their body
- transfers his own gamete into rival
- females can decide who fertilizes her eggs by copulating with multiple males
- the most recent male copulation usually fertilizes her eggs
50
How do chickens exhibit sperm competition?
hens will eject some of the semen they receive, especially those of lower-ranks
51
How do dunnocks exhibit sperm competition?
males will peck at partner cloaca if he finds another male, to eject other male’s sperm
52
Why might female birds engage in extra-pair copulation?
possess tubules in uterus to store sperm
53
Why might males stay with a female after mating (5)
- to ensure reproduction is successful
- to lure other males away from the female
- seal mate’s genitals with secretions
- sacrifice themselves
- seen in spiders
- males may lose time and energy finding another mate
54
What is the benefit of males staying with a female after mating?
reduces chance female will copulate with another male
55
Why might baboon males stay with females after copulating?
dominant males must guard fertile partners to prevent other males from copulating with them
56
What should we expect for male guarding to be adaptive?
cost of loss opportunity to mate must be less than benefit of monopolizing females
57
Why is it beneficial for male milkweed beetles to mate guard?
- 50% of separated females got a new mate within 30 minutes
- only 25% of separated males found a new mate within 30 minutes
- male only needs to fertilize 40$ of a female eggs to benefit from mate guarding
58
How do seychelles warblers exhibit mate guarding?
when egg appears, males ends their mate guarding
59
Key reproductive decisions controlled primarily by females (4)
egg investment (what materials, how much, what to place in an egg)
mate choice (which male or males will be granted the right to be a sperm donor)
egg fertilization (which sperm aactually fertilizes)
offspring investment (how much maintenance and care goes to each embryo/ offspring)
60
Ways in which males influence female reproduction?
resources transferred to female (influence egg investment, mate choice, or egg fertilization)
elaborate courtship (influence mate choice/ egg fertilization)
sexual coercion (overcome female preferences for other males)
infanticide (overcome female decisions about offspring investment)
61
Why might favorable traits be spread? (2)
- Mates with favorable traits have higher reproductive success
- preference for these traits adds selective pressure, to allow it to spread
62
How do chimpanzees exhibit favorable practical traits?
females are more likely to mate with males who give them hunt
63
How do dung beetles exhibit favorable practical traits?
males rolls up dung and offers it to females
64
How do hanging flies exhibit favorable practical traits?
- males benefit from offering nuptial gifts
- the larger the food item it is, the more sperm the male can transfer
65
How do redback spiders exhibit mate selection?
- flips themselves into jaw of females after blocking sperm receptacles with their pedipalps
- gets eaten 2/3 of the time
66
Why might it be benficial for male redback spiders to commit sexual suicide (2)?
- males that sacrifice themselves are more likely to fertilize
- males have low survival rate, so they don’t need much incentive for this traits to be adapative
67
Why do most spiders commit sexual suicide (2)
- most suicidal male spiders sacrifice pedipalps after mating
- sexual suicide occurs as males thus have no chance of additional matings
68
How do sticklebacks select for parental care?
- females prefer males that can shake more during courtship
- males that shake better can fan eggs better
or
- males with redder bellies are preferred
- redder bellies can fan eggs better (possibly because they get red from a diet, and redder belly means better diet)
69
How do zebra finches select for parental care?
- caratenoids may advertised suitability of males by providing red plumage
- males with brighter red beaks have a stronger immune response and is favored
- females lay larger eggs for these males
70
How do blue tits select for parental care?
males with bright yellow breasts are better at raising young
71
What is good parent theory?
various traits are sexually selected indicators of a male’s ability to do parental care
72
How do damselflies exhibit good parent theory?
- males are chosen on the basis of cus linked to their body temperauter
- how fast one can beat wings
- females choose male parenting indirectly, as males with hotter territories have shorter egg development time
73
How do male canaries attract females?
- mate choice is influenced by the ability of a male to sing particular portion of the male song: the A phrase
- when primed by estradiol, females react to a well-trilled A phrase by assuming the precopulatory position
- females prefer an exaggerated A phrases performed by a computer
74
What should we expect mate choice to have in males?
the greater the sensory stimulation provided by males, the more attractive he is
75
How do tropical birds exhibit sensory stimulation?
- intense jump-snap display and male reproductive success
- the faster he is, the higher success
- females choose males whose motor skills are best, by choosing intense displays
76
How might have ornamentation evolved?
if male ornaments evolved because of female choice sexual selection, enhanced males courtship traits should enhance his copulatory success
77
How do long-tailed widowbirds exhibit ornamentation?
- males advertise huge tails
- when tail feathers are removed and added to others, those with the new tails were more attractive than those that had them removed
78
What may serve as a test of male quality?
male performance during or just after copulation
79
How do digger wasps select?
females use tactile signals from mounted males to decide whether to mate again
80
What is cryptic female choice?
female selection for a choice hidden from humans
81
What is an example of cryptic female choice?
in species with polyandrous females, mating success may be linked to morphology of his sperm delivery organ, or how its used during mating
82
How do oriental beetles exhibit cryptic female choice?
- males have spiny hooks on penises
- larger hooks mean higher percentage of eggs fertilized in following mating events
83
Example of female choosiness resulting in fitness loss for females
rejected males may become violent (infanticide)
84
What ideas counters the idea thaat males manipulate choosy females?
- countered by communication idea, where receiver gains no benefit
- choosy females should leave more surviving offspring by responding to appropriate signals
85
Four theories on how female benefits could lead to extreme male ornamentation/ courtship displays if males provide no material benefits?
healthy mates
good genes
runaway selection
chase-away selection
86
Why might it be difficult to discern among the four theories of male display evolution?
difficult to discriminate between healthy mates, good genes, and runaway selection female because they are not mutually exclusive
87
What is healthy mate hypothesis?
health of a sexual partner- females choices are focused on health of a potential partner, or his parasite load
88
What should we expect if health of a sexual partner is selected (2)
- may be indicated through courtship display or appearance
- females that use these traits to decide which males are less likely to carry disease or parasites
89
What is the good genes hypothesis?
quality of male genes may play a role
90
What should we expect if the good genes hypothesis was correct (3)?
- female preference for ornaments or displays helps females choose partners with good genes
- genes may contributed to male immune system effectiveness
- selection for honest signals of non-infection would lead to species with many potential parasites to evolve striking plumage
91
Why might parasites affect plumage (3)
- plumage would be hard to maintain if bird is parasitized due to stress
- correlation in birds with plumage brightness and blood parasites
- males at special risk of infection compete with signals that indicate their condition
92
How might genetics and how genes are passed affect the good genes hypotheis?
females choose males that are genetically different to promote heterozygosity and prevent recessive alleles issues
93
What must peacocks exhibit for good genes hypothesis to be correct? (5)
- males should genetically differ in ways relevant to their survival
- male behavior and ornamentation should provide accurate info on survival value of these genes
- females should use this info to select mate
- offspring of chosen males should benefit from their mother’s mate choice
- males should accurately signal their genetic quality, and females should pay attention to these signals because offspring would derive genetic benefits
94
What did an experiment with peacocks show of the good genes hypothesis?
- initially found that males killed by foxes had shorter tails than surviving ones
- most devoured males did not mate in previous seasons
- suggests females can discriminate between males of different survival potential
- offsprings of males with larger eyespots had higher weight and a higher survival rate
95
What hypothesis did the peacocks supprot (2)?
- could be side effects of runaway selection
- brightly adorned males may be less parasitized, supporting healthy male hypotheses
96
What does research of the good genes hypothesis in other birds show?
- females may invest differently according to attractiveness to her partner
- birds can adjust testosterone contributed to egg according to mate attractiveness
- effects could be credited to a male’s genetic quality, but may arise from female manipulation of her parental investment
97
What is runaway sexual selection? (2)
- female choice creates a genetic link between mate choice by females and that male trait, and that female choice begins to select on itself
- leads to evolution for increasingly extreme traits
98
What does runaway selection say about traits?
traits don't have to have a utilitarian function
99
How do canary sogns exhibit runaway selection?
- sexual preference for songs could be adaptive for females if sons inherit the capacity to sing attractive songs
- sons become appealing in the next generation
100
What is chase away selection influenced by, and what does it result in?
- influenced by sexual conflict
- often results in extreme ornaments and elaborate courtship behavior
101
What is an example of sexual conflict?
ex- females turning down sexually motivated males
102
How do topi exhibit sexual selection?
- males in central territories and may become sperm depleted
- may refuse to mate with the same female, saving it for new partners
- jilted females may respond by attacking the male and disrupting mounting of newcomers
103
Why might males commit infanticide (2)?
- males kill infant to induce females to become sexually receptive
- males kill to force unwilling females to mate
104
What kind of mutations do chase-away selections involve?
a mutation for a novel display trait which taps into preexisting sensory bias that affects female mate preference
105
What should we expect of females regarding a chase-away selection mutation? (2)
- as exploitative traits spreads, females would be resistant to just the attractiveness
- females would evolve higher thresholds for responsiveness, and selection would favor males with more exaggerated traits to overcome that resistance
106
How does run-away selection differ from chase-away selection?
differs from run-away selection, as it doesn’t benefit both individuals
107
What is the end result of chase away selection?
females would not gain material or genetic benefit from mating with “stimulating” males
108
Why is reproduction a battle?
reproduction is a battle between sexes for maximum genetic advantage, regardless any csot to the opposite sex
109
How might females gain in a reproductive conflict? (4)
- in cases of conflict, females may be subject to higher risk. but gain if her sons carry these traits
- physical conflict may be a way to judge ability of male to deliver sons that will overcome female resistance
- aggressive courtship may be a way that females choose males whose sons will do better in male-male aggression
- females may be winning by losing if they mate with males that force then to copualtion, or somehow block them from preferences for other males
110
How do fruit flies exhibit chase away selection?
- male transfers a protein that boosts male fertilization success at the expense of females
- females have shorter lives and disrupted sleep patterns
- males get a net gain, as they are unlikely to mate with a female more than once
111
What was seen in an experiment forcing monogamy in fruitflies?
- males lost their toxic protein production over time
- females lost some resistance to the protein
- females from monogamous population paired with control males lost fecundity and survival rates
- females prefer to reproduce with larger males
- larger males may be more likely to transfer more toxins
112
How do bed bugs exhibit chase away selection, and how might it have evolved?
- males transfer sperm by stabbing females, injecting into the circulatory system
- may have evolved to seminate sexually resistance females that may have already mated with another male
- females mating at high frequency laid fewer eggs and lived less
- ejaculate may boost female fitness with moderate levels of insemination
