Chapter Ten: Reproductive Behavior Flashcards
what is the red queen hypothesis
populations are always evolving even just to maintain the current adaptation (stabilizing selection)
why are clones of fish so vulnerable to parasites
if a parasite can kill one of them, it can kill all of them
what is the main value of sex
genetic diversity
genetic diversity is critical for ___ and ___
adaptation and survival
term that means two different size gametes for male and female
anisogamy
anisogamy leads to different ___
selective pressures
each sex has a different gamete strategy that allows it to maximize ___
reproductive success
for the small/fast gamete, selection favors ___ number of offspring and ___ parental investment
high
low
for the large/nutritional gamete, selection favors ___ number of offspring and ___ parental investment
low
high
differences in ____ between sexes may arise from differences in parental investment
sexual behavior
different reproductive rates lead to different ____
optimal behaviors
a low parental investment leads to a ____ potential reproductive rate and therefore ____ levels of sexual activity
high
high
a high parental investment leads to a ____ potential reproductive rate and therefore ____ levels of sexual activity
low
low
effort invested in young at the expense of other offspring
parental investment
what is a fertility cost
a female’s reproductive rate and success is limited by the number of eggs produced
what is a mating cost
a male’s reproductive rate and success is limited by the number of females he can find and mate with
what is a male-biased operational sex ratio
one in which there are more males ready to mate than females (males have a mating cost and females have a fertility cost)
in a male-biased operational sex ratio, which is the choosy sex? which is the sex that competes for mates?
females are the choosy sex
males compete for mates
when would you expect males to be the choosy sex?
when more females are ready to mate than males
example of a species in which males are the choosy sex
mormon crickets
why do male Mormon crickets pay a higher fertility cost
produce a spermatophore that includes sperm and nutrients for the female
male only mates once, female mates more than once
female-biased sex ratio
what kind of factors influence individual survival
good habitat, foraging ability, anti-predator behavior, etc.
how can traits evolve that make it difficult for an animal to forage or escape from a predator?
if the trait increases reproductive success, even if it decreases survival
what is Zahavi’s handicap principal
elaborate plumage handicaps a male, so the ability to survive with it is an honest signal to potential mates
natural selection for traits that could decrease survival but increase reproductive success because they help you acquire a mate
sexual selection
sexual selection traits come with ____
trade-offs
in dung beetles, growing a bigger horn requires a trade off of ____
a smaller eye
four ways in which females try to control reproductive decisions
- egg investment
- mate choice
- egg fertilization
- offspring investment
what materials and how much off them to place in an egg
egg investment
which male or males will be granted the right to mate with her
mate choice
which sperm to use to fertilize each egg
egg fertilization
how much maintenance and care goes to each embryo and offspring
offspring investment
four ways in which males try to control reproductive decisions
- resources transferred to female
- elaborate courtship
- sexual coercion
- infanticide
male to male (or non-choosy sex to non-choosy sex) competition is known as
intrasexual competition
in intrasexual selection, males battle and the winner ____
gets to mate with the female
there is a strong relationship between ___ and ___ in intrasexual selection
fight success and reproductive success
female choice is known as
intersexual selection
a male can bring a female a _____ to try and get her to mate with him
nuptial gift
two examples of a nuptial gift
food and terminal mating
male balloon flies give ___, ____, or ____ to females
food, food wrapped in silk, or an empty silk balloon
what is terminal mating
mate and then die
what does the male redback spider do after mating; why is this beneficial
he crawls into her mouth and she eats him; she gets a meal and nobody else can mate with her because he administers a plug
if a male doesn’t give the female material benefits, what does she get in return for choosing him to mate with?
healthy mates
good genes
females prefer traits that are indicative of male ___ and ___
health and viability
three alternative mating strategies for males that are not the top dog
- make friends
- premature ejaculation
- satellite mating
females may mate with a non-dominant ___
friend
male friends may ____ on dominant male
gang up
species in which making friends can help non-dominant males mate
baboons
premature ejaculation decreases _____
copulatory time
three strategies for satellite mating
- intercept female on her way to the dominant male
- sneak in while female is with dominant male
- mimic a female so that you can get close and then try to mate
bluegill fish are ____ fertilizers
external
dominant bluegill male ____
sneaker male ____
satellite male ____
guards nest to attract females
slips in between spawning pair to add sperm of his own
mimics female and slips between her and dominant male, dominant male thinks he’s mating two females
a hereditary alternative mating strategy should be ___ and reproductive success should be ___
genetically constrained
equal
a conditional alternative mating strategy should be ___ and reproductive success should be ___
environmentally induced
different
what are the three reproductive strategies used by scorpionfly males
guard food, saliva gift, and force
reproductive success for scorpionfly males is higher when they guard food compared to the other two strategies, making it a _____ strategy
conditional
three phenotypes for sponge isopod males
alpha, beta, gamma
sponge isopod phenotypes have equal reproductive success, making it a ____ strategy
hereditary
sperm competition is only seen when ____
females commonly mate with more than one male
two methods of sperm competition
- make more/better sperm
- internal mechanisms
two examples of internal mechanisms for sperm competition
- penis scrub brush to remove previously ejaculated sperm from a different male
- cloaca pecking to make female eject previous sperm from a different male
mate guarding occurs when _____
female is likely to mate again or females are scarce
three methods of mate guarding
- literally guard her
- hold on to her
- seal genitalia with secretions or plugs
