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72 Cards in this Set
- Front
- Back
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Describe the evolutionary phylogeny of bower-builders.
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No other bird species builds anything like these elaborate display structures, and so the trait appears to have evolved just once. A single common ancestor gave rise to the cluster of bower-building species.
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What is the mate quality advertisement hypothesis of bower building?
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Useful information about his quality as a mate to females, and was rewarded when discriminating females copulated wit him. Males that build better bowers do have fewer ectoparasitic feather mites than those that make less appealing display structures.
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WHat does a male's contribution of genes to the next generation generally depend on?
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Depends on how many sexual partners he has: the more mates, the more eggs fertilized, the more descendants produced, and the greater the male's fitness relative to less sexually successful individuals.
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What is the operational sex ratio?
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The ratio of sexually receptive males to receptive females
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What led to the separate evolution of different gametes?
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No single kind of gamete could be equally good at fertilizing and development.
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What is a sex role reversal?
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Species in which males make the larger parental investment ~ the operational sex ratio should be biased toward females, leading to female competition
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Do males or females compete for mates in pipefish, (which have pregnant males)?
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Females compete
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Are sex role reversals dependent solely on the degree to which males provide more parental investment than females?
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No; these reversals may depend on the ability of females to produce a sufficient number of eggs in a short enough time to supply several males with clutches to brood.
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What type of mating is observed in seahorse species whose females cannot achieve a high enough rate of egg production to warrant mating with more than one male?
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Monogamy is the rule
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Give an example of a species in which the reproductive capacity of the females can exceed that of males.
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The flightless Mormon cricket, (which is actually a katydid); when they mate, males transfer an enormous edible spermatophore to females; given that the spermatophore constitutes 25% of the male's body mass, most male Mormon crickets probably cannot mate more than once; in contrast, females may be able to produce several clutches of eggs
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Describe the skewed sex role reversal that results from females' higher reproductive potential in Mormon crickets.
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Males often behavior in a discriminating manner, refusing to transfer a spermatophore to a lightweight female in favor of a heavier, more fecund partner
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Which sex competes for access to members of the other sex?
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The sex with the higher reproductive potential competes
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What is intrasexual selection?
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Members of one sex compete with one another for access to the other sex.
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What is male dominance almost always positively correlated with?
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Male mating success, as indicated by the male's ability to guard a female throughout her fertile phase.
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Are the majority of babies sired by the dominant male?
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Yes; reproductive success is tightly correlated with dominance rank
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How do socially subordinate baboons compensate for their inability to physically dominate others in their group?
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Lower-ranking males can and do develop friendships with particular females, relationships that do not depend entirely on phsycial dominance, but on willingness of a male to protect a given female's offspring. Once a male, even a moderately subordinate one, has demonstrated that he is willing and able to provide protection for a female and her infant, that female may seek him out when she enters estrus again.
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How do little iguanas compensate for the fact that larger iguanas might remove him from the female's back?
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The little iguanas ejaculated prior to any copulation; still, the larger males who inseminate at their leisure reproduce more successfully.
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When is the ability to adopt the "inferior" tactic adaptive?
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If small or otherwise handicapped individuals gain more fitness than they would if they were to try to use the tactics of their dominant opponents
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Describe the satellite male mating tactic of the horseshoe crab?
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Some males patrol the water off the beaches, finding and grasping females heading toward shore to lay their eggs. Other males swim onto the beach alone and crowd around paired couples. An attached male fertilizes at least 10 percent more eggs than any competing satellite male. Staellite males, however, do better than they would if they tried to attach themselves to a female at sea only to be pushed aside or displace by males that are in better physical condition
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Describe the different mating techniques of males in the amphipod genus, Jassa.
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Small males which have been stunted by a second-rate diet as theyw ere growing up, try to sneak matings with females, whereas those males that were blessed with a high-protein planktonic diet become large, aggressive individuals able to monopolize some potential mates.q
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Describe the interactions of the three types of marine isopods, Paracerceis sculpta.
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The big alpha males attempt to exclude other males from interior cavities of sponges that have one or more females living in them. If a resident alpha encounters another alpha male in a sponge, a battle ensues that may last hours. Should an alpha male find a small gamma isopod, he simply grasps him and throws him out. If an alpha male encounters a medium male, the beta behaves like a female and the alpha courts him ineffectually, allowing the betas to coexist with the alphas.
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Is the mean reproductive success equal when different mating strategies are caused by the environment or hereditary?
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Environment
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Is the mean reproductive success equal or inequal when different mating strategies are caused by hereditary?
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Equal
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how can three genetically distinct phenotypes coexist that all have the same fitness?
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The different genotypes are in different frequencies.
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Did the three types of marine isopods have the same fitness?
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Yes, there was not a significant difference; exist in different frequencies.
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When a particular strategy becomes rare, does its fitness increase or decrease?
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Increase
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Is any one phenotype ever eliminated under frequency-dependent selection?
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No, because the rarer strategy increases in fitness
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What is it called when there is evidence of competition among males with respect to the fertilization success of their sperm?
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Sperm competition
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If the sperm of some males have a consistent advantage in the race to fertilize eggs, will counting up a male's spawnings or copulatory partners measure his fitness accurately?
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No
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How does a male damselfly's penis work?
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He rhythmically pumps his abdomen up and down, during which time his spiky penis acts as a scrub brush, catching and drawing out any sperm already stored in the female's sperm storage organ. Removes between 90 and 100 percent of any competing spermbefore he releases his own gametes
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Is sperm competition something males simply do to one another?
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No, females play a role; for example, females of the black-winged damselfly could arrange fo rhte removal of some sperm simply by mating with a second male after copulating with an individual that she did not favor; some females can even expel sperm themselves.
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What is one way males can sometimes give their sperm an advantage over those of their rivals?
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Increase the nubmer of sperm ejaculated inoto a female that has already mated with another male. Male meadow voles boost the sperm count of an ejaculate by more than 50 percent when copulating with a female in a palce where teh odors of another male are present.
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What is it called when males physically prevent their partenrs from mating again after insemination?
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Mate guarding
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What are four methods of mate-guarding?
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1. Keep mates occupied after mating
2. Males deceptively lure new suitors away from the female 3. Males seal a partner's genitalia with various secretions 4. In orb-weaving spiders, males die within minutes after inserting both pedipalps into her genital opening, which then inflate after insertion |
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What is a cost of extra egg fertilization with one female?
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Loss of opportunity to seek out other females
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When do the benefits of mate guarding increase?
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They increase with the probability that unguarded females will mate again and use the sperm of later partners to fertilize their eggs.
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In relation to what do male Seychelle warblers adjust their investment in mate guarding?
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In relation to the risk of cuckoldry, which ought to be affected by how many males live in close proximity to a fertile female and her partner.
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How do male redback spiders seem to take extraordinary measures to put themselves in harm's way?
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As a male transfers sperm to a female, he performs a somersault that literally throws his body into his partner's jaws
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Do eaten males fertilize more of their partner's eggs than uneaten males?
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Yes, partly because a cannibalistic female spider is less likely to mate again promptly
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Why are the costs of being cannibalized very low for male redbacks?
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Fewer than 20 percent manage to locate a first mate, suggesting that the odds that a male could find a second partner if he should survive his initial mating are exceedingly poor
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Has there been an established link between song quality and parental ability?
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Yes; seen in the male sedge warbler
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How might the red or yellow components of a male's color pattern indicate something about their quality as a mate?
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Cartenoid-based color patterns reveal something about the health of the male; specifically, the quality of the bird's immune system, which is believed to benefit from access to an adequate supply of carotenoids; female zebra finches find experimentally carotenoid-enhanced males more attractive than those that have been kept on normal diets
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When certain birds were reared by foster parents, was the size of the fledglings a function of the brightness of their genetic or foster fathers?
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Foster
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What is good parent theory?
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Explains aspects of male color, ornamentation, and courtship behavior as sexually selected indicators of a male's capacity to provide parental care
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What is the certain portion of the male song called that heavily influences a female's choice of mate?
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A phrase
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What is the A phrase composed of?
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Two-note syllables
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What is the preferable A phrase?
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FEmales that hear an A phrase trill that packs many syllables into a second of song readily adopt the precopulatory position
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How might the A phrase indicate the physical quality of a bird?
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Birds must control their syrinx to produce the A phrase; not only must hte moevmenets of hte two tubes of hte syrinx be integrated perfectly, a nauerally demanding exercise, but what goes on in the synrinx also has to be ain synchrony with the bird's breathing, since air is required for sound production; being able to sing a very rapid trill might constitute a demonstration fthe male's physiological state
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Has there been a correlation found between the elaborateness of a penis, and the number of females mated with during a breeding cycle?
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A slight correlation; not seen as much in primates
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Why might spiny penises have occurred?
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Reduces the willingness of females to mate again ~ males with the spinier penises would be the ones that had the shorter periods of females receptivity.
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In species where males have spiny penises, are periods of female sexual receptivity usually shorter or longer?
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Shorter
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Even if males have nothing useful to offer other than gametes, (no material benefits), why might females still be choosy?
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Males can give females a variety of STDs
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What is the theory called that female preferences are focused on male courtship displays and ornaments that serve as indicators of a potential sexual partner's health or parasite load?
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Healthy mate theory
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How does the healthy mate theory apply to bower-birds?
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Male bower-birds with high-quality bowers are less likely to carry ectoparasites in their feathers, so females that copulate with good bower builders should be less likely to pick up feather lice as a result of contact with these males
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What is the theory called, which proposeses that male courtship displays and ornaments provide information to females that enables them to choose males with viability-enhancing genes?
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Good genes theory
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Why might females prefer males with large repertoires?
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Increases the heterozygosity of their offspring; since females somehow ensure that their eggs are fertilized by those sperm that are genetically least like the eggs' genomes
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Why is the brightness of the yellow plumage of the goldfinch correlated with?
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The bird's condition when it is molting; accordingly, females prefer to mate with bright yellow males
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Why might brightly colored feathers have evolved to correspond with the parasite-level of the bird?
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Brightly colored feathers are difficult to produce and maintain when a bird is parasitized because parasitic infection causes physiologically stress.
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What is the runaway selection theory?
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Discriminating females acquire sperm with genes whose primary effect is to influence their daughters to prefer the male traits their mother found attractive and to endow their sons with attributes that will be preferred by most females
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How might the response to certain cues have evolved?
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A slight majority of the females in an ancestral population had a preference for a certain male characteristic, perhaps initially because the preferred traitw as indicative of some survival advantage enjoyed by the male. Females that mated with preferred amels would have produced offspring that inherited the genes for the mate preference from their mothers and the genes for the attractive male character from their fathers. Sons that expressed the preferred trait would have enjoyed higher fitness, in part simply because they possessed the key cues that females found attractive. In addition, daughters that responded positively to those male cues would have gained by producing sexy sons with the trait that many females liked. The mate preference might take on a life of its own , resulting in the production of sons that are exceptionally attractive to females and the production of daughters that will choose this kind of male for their own mates.
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What is the theory called that initial mate preference took on a life of its own, leading to the development of elaborate male characteristics?
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RUnaway process
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Might runaway selection yield mate choice for arbitrary characteristics that are a burden to individuals in terms of survival?
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Yes; a disadvnatage in every sense except that females mate preferentially with males that have them
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Female preferences and male traits that originated through the __________ process could then be caught up by the ________ process.
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Good genes; runaway
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How might more fit males be selected for in the runaway process?
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If at the end of a period of runaway selection, males evolved extreme ornaments and elaborate displays, then only individuals in excellent physiological condition would be able to develop, maintain, and deploy their ornaments in effective displays
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How does the good gene hypothesis apply to gray treefrogs?
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Males that give calls of relatively long duration sire tadpoles that develop faster than their half-siblings whose father could manage only short calls.
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What do female mallards and black grouse respectively do after copulating with unusually attractive males?
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Mallards make larger eggs; black grouse produce and lay more eggs
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What is the chase-away selection theory?
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An exploitation and conflict between the sexes, rather than cooperation and mutual benefit, could drive the process in the following manner. A male happened to have a mutuation yielding a novel display trait, one that managed to tap into a preexisting sensory bias of the females of his species. A male that could activate that preexisting preference might induce females to mate with him even though he might not provide the material or genetic benefits offered by other males in the population. The resulting spread of such exploitative males over time would create selection on females favoring those that had psycholgoical resistance to the purely attractive display trait. AS females with a higher threshold for sexual responsiveness to the exploitative trait spread, selection would then favor males able to overcome female resistance, which might be achieved by mutations that further exaggerated the original male signal.
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What is ACp62F?
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A protein that boosts male fertilization success, perhaps by damaging rival sperm), at the expense of females, whose lives are shortened and whose fecundity is lowered.
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How are female fruit flies engaged in hidden combat with males?
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Female fruit flies actually reduce their fitness by preferring to mate with larger males, which they choose either because they find body size an attractive feature in itself or large body size is correlated with some other attractive feature; yet they deal with rather nasty chemicals they receive during mating
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Describe the insemination method of bedbugs?
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Males use their knifelike intromittent organ to stab a female in her abdomen before injecting their sperm directly into her circulatory system
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How did the bedbug insemination method presumably evolve?
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Presumably evolved originally as a result of males injecting their sperm in this way into sexually resistant females that had already acquired sperm from earlier partners via the traditional, less damaging mode of insemination.
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Describe how female bedbugs have evolved a counteradaptation that at least reduces the damaging effects of male sexual behavior.
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Under the abdominal cuticle of female bedbugs, at athe site where traumatic insemination typically occurs, lies a special organ called the spermalege. The spermalege may help females cope with pathogens that males incidentally infect them with during insemination.
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