Final Exam Flashcards

Question

Mating Systems

Answer 1

Monogamy - one female, one male Polyandry - mating system in which female has several partners in breeding season Polygyny - mating system in which male fertilizes the eggs of several partners in breeding season Circumstances --> Strategy

Answer 2

females larger than males In scramble competition, males race to get access to receptive/ reproductively valuable females Traits favored = well developed sense/locomotory organs, which can lead to SEXUALLY DIMORPHIC SENSE ORGANS - nervous system differences Males may be able to smell/move more quickly to find females Also favored = early search, swift mate location - males mature more quickly than females to get them faster - males will be SMALLER - LESS TIME TO DEVELOP - REVERSED SEXUAL SIZE DIMORPHISM - females larger ex: redback spider - need to search for females - strong FIRST MALE SPERM PRECEDENCE - male who gets to female first gets to father most of her children - Paternity strongly biased towards the first male to mate - Males mature EARLIER so they can start to search faster - Males are SMALLER - the first male to reach a female will fertilize most of her eggs, so TRADE-OFF between size and speed! males mature much earlier (and much smaller)than females, they can start the search early and try to beat their rivals

Answer 3

Sexual selection: traits favored because they increase success in competition over other potential mates "Other" Natural Selection: traits favored because they increase LRS in ways not related to competition over mates Sexual selection can often favor traits that decrease survival.. SS: ex: Red throat of frigate bird increases probability of mating successfully but increases risk of predation; Favored by sexual selection but OPPOSED by ‘other’ natural selection O: ex: Brood patch of bird increases chance of reproducing successfully, but not important in competition over mates; Favored by ‘other’ natural selection SS and O: ex: Many eyes of jumping spider increase chance of finding a mate, but also of capturing prey; Favored by other natural selection & sexual selection

Answer 4

A promiscuous mating behaviour in monogamous species A mating by a male or female with someone other than his or her primary partner in a seemingly monogamous species Ex: Collared Flycatcher - use sperm storage system to bias male fertilization chances - can be stored for long periods of time (1 month) - slipping away to give advantage to male with larger white forehead patch BENEFIT: gain 'good genes' lacking in bonded male, increasing fitness of offspring; extra-pair paternity only if flycatcher chooses; must have greater genetic quality (white patch), improving survivability and reproductive success of offspring; more common when male genetic quality is highly variable COST: extra energy in reproducing Ex: Warblers - false egg - guarder males used false egg cue to stop mate guarding - female warbler still fertile - female warbler copulated with extra-pair partners, often fertilizing his sperm Males do so to have maximum mates BENEFIT: due to having such low parental investment, it is evolutionarily adaptive for men to copulate with as many women as possible, as it will allow them to spread their genes with little risk of future investment; ex: house wren 2 mates=9 offspring, 1 mate=<6 COST:

Answer 5

duration amount timing quality trade-off between current & future reproduction benefits: increased survival& success of offspring costs: decrease likelihood of successful future reproduction, physiological costs, opportunity costs(foraging & other matings) parental care will only evolve if it results in a net fitness increase

Answer 6

the selection of combinations of traits in an organism that trade off between quantity and quality of offspring r = focus upon either increased quantity of offspring at the expense of individual parental investment k = reduced quantity of offspring with a corresponding increased parental investment of K-strategists, varies widely, seemingly to promote success in particular environments r-selected species are those that emphasize high growth rates, typically exploit less-crowded ecological niches, and produce many offspring, each of which has a relatively low probability of surviving to adulthood ex:dandelion •Parents’ strategy: intelligent, autonomous, but expensive offspring•development of traits necessary for success after birth:•learning•physical abilities•development depends on food that is scarce/difficult to obtain K-selected species display traits associated with living at densities close to carrying capacity and typically are strong competitors in such crowded niches that invest more heavily in fewer offspring, each of which has a relatively high probability of surviving to adulthood ex:elephant ------- K selection (carrying capacity): stable environments •larger body size •slower development •longer lifespan Key factor affecting success of offspring: intense intraspecific competition Iteroparity -produce offspring in successive bouts - small # of young that receive intensive care - relatively low mortality rate of young K-selection ex: ex: old world monkeys 25% of life focused on r, brain size ability to work in complex groups ex: black eagles juveniles fed by parents long after they could feed themselves fitness; hunting ability r-Selection ex: ex: salmon - single intense breeding event, die, many offspring ex: redback spiders: thousands, no care, high mortality, spiderlings able to catch prey autonomously immediately

Answer 7

1. Sex with higher initial investment 2. Sex with lower cost/benefit ratio care will evolve in the sex for which care yields greatest net fitness increasex

Answer 8

when parents gain fitness by withholding parental care or resources from some offspring in order to invest in others now or later - offspring desire greater investment than their parents provide - parents try to allocate resources to ensure the maximum number of offspring survive - conflict occurs when offspring want more resources than parent willing to give will at some point prefer to invest in future not current the evolutionary conflict arising from differences in optimal parental investment (PI) in an offspring from the standpoint of the parent and the offspring o Natural selection favors different optimal for parent & offspring o Everything parent gives offspring, it doesn't keep for itself or other offspring ex: red-mason bee -- preferential to first offspring, females, more likely to survive, physiological conditon declines, foraging less good, ex: burying beetle, earwigs == earwigs respond to chemical cues of well-fed nymphs

Answer 9

siblicide obligative faculative obligate vs. facultative siblicide OBLIGATIVE ex: nazca booby (first chick always kills second, only 60% of first-laid eggs hatch, laying two eggs reduces complete nest failure by 16%); FACULATIVE blue-footed booby (when siblicide occurs, first chick always kills second, only in food shortage, older one only kills younger one when first-born weight drops to 75% of normal) INSURANCE AGAINST FAILURE, INCREASES CHANCE OF REPRODUCTIVE SUCCESS

Answer 10

Parental Investment (gamete production, other) High (f) Low (m) [few, energy-rich eggs] [many, low-energy sperm] Potential Reproductive Rate (max number of offspring given unlimited access to opposite sex gametes) Low (f) High (m) Time-Out Period (time spent acquiring resources for gametes and caring for young) High (f) Low (m) ``` Operational Sex Ration (OCR) Few active (f) Many active (m) ``` [Heavily biased toward males] [Females have nothing to gain from copulating again --> many fewer sexually active females]

Answer 11

Fitness advantage enjoyed by offspring disposal of siblings Faculatative Obligate Facultative occurs later on in development; after they have been born Siblicide occurs as soon as it hatches, EX: Black eagles Ample resources —> it might not happen Obligate will always happen Insurance egg: lay egg to provide insurance that their efforts aren’t failed, response to a high risk situation; obligate, to make sure there is one at least Extra reproductive hypothesis: faculatative siblicide, Extra one, bc may survive; dependent upon availability of resource, siblicide will not occur if enough is present ---- OBLIGATIVE ex: nazca booby (first chick always kills second, only 60% of first-laid eggs hatch, laying two eggs reduces complete nest failure by 16%); FACULATIVE blue-footed booby (when siblicide occurs, first chick always kills second, only in food shortage, older one only kills younger one when first-born weight drops to 75% of normal) INSURANCE AGAINST FAILURE, INCREASES CHANCE OF REPRODUCTIVE SUCCESS

Answer 12

Females of some bird species lay their eggs in other nests or the nests of other species that are smaller (usually closely related) Brood parasitism — warbler and cookoo; supernormal stimuli; —> adapted that way to ensure the warbler’s fitness; cookoo will destroy magpie the nest warbler may push out own eggs when trying to get rid of cuckoo accept eggs at end of mating season, little time to renest unable to remove/grasp large eggs Push out the male they’re helping and take over the nest

Answer 13

Ex of nuptial gift, female-biased OSR Mormon cricket Male gives female nutrient-rich spermatophore (nutrients to produce more eggs) Refuses lightweight females

Answer 14

Female katydid only competes to mate when food is scarce, making the male's spermatophore especially valuable Males especially choosy, females fight OSR switches when food is no longer scarce Dependent on pollen quantities Low food condition: female-biased OSR,

Answer 15

Female katydid only competes to mate when food is scarce, making the male's spermatophore especially valuable Males especially choosy, females fight OSR switches when food is no longer scarce Dependent on pollen quantities Low food condition: female biased - Higher

Answer 16

When parental investment is high for an organism OSR is low Fewer sexually active females Ex: High P.I. for females More sexually active males Male-biased OSR

Answer 17

Hamilton’s Rule [ inclusive fitness] rB > C indirect fitness > direct fitness r=relatedness B=benefit to recipient for altruistic behavior C=cost of altruistic behavior

Answer 18

Traits favored because they increase lifetime reproductive success (LRS)

Answer 19

within a species, the advantage some have over others to reproduce

Answer 20

Monogamous species tend to form lifelong breeding pairs, share a nest, guard against intruders together, and take care of offspring together Promiscuous species tend to have low levels of social affiliation, do not mate with one specific partner, and usually only the females care for offspring

Answer 21

When parental investment is high for an organism OSR is low Fewer sexually active Ex: High P.I. for females More sexually active males Male-biased OSR OSR IS BIASED TOWARD WHOEVER HAS LOWER PI however competes is the one with the bias

Answer 22

Many species of animals are eusocial, living in large colonies. Examples: honeybees, termites, naked mole rats Eusociality has three main components: 1. Cooperative brood care 2. Cohabiting, overlapping generations 3. Division of labor, including non-reproductive castes (e.g. worker bees)

Answer 23

Brood patch of bird increases chance of reproducing successfully, but not important in competition over mates Favored by ‘other’ natural selection

Answer 24

Many eyes of jumping spider Increase chance of finding a mate, but also of capturing prey Favored by other natural selection & sexual selection

Answer 25

Red throat of Frigate bird Increases probability of mating successfully- but increases risk of predation Favored by sexual selection - but OPPOSED by ‘other’ natural selection

Answer 26

Mate Choice Intersexual Selection: making themselves more attractive to opposite sex (females) Competition for Mates: Intrasexual: by intimidating, deterring, attacking same-sex rivals (males)

Answer 27

Facial expressions - universality, development, evolution Function " Signal passive/aggressive feelings " Elicit positive/aggressive responses Causation " Ver specific sets of muscles control facial expressions Development " Begin smiling at faces around 40 days old " Use responsive smiling by 2 months of age " Study faces by the end of second month " Focuses on mouth movements at 5 months === ``` Evolution Bearing teeth threat Half baring teeth- stops to end threat Submissive primate grimace Human smile ```

Answer 28

Human sexual attraction - how it related to OSR | o Males are quantity based and females are quality based

Answer 29

Relationships between human attractive features and fitness Males are attracted to females with sloping jaw and full lips Females are attracted to square jaw and prominent brow o Both are attracted to symmetry o Waist to hip ratio " 0.7 which is strongly correlated with health and fertility for women " 0.9 which is strongly correlated with health, fertility, and low cancers rates for men

Answer 30

- Potential human innate releasing mechanisms - neoteny features o People prefer babylike animals and things- ex. puppies, babies, kittens o Large Round head, large round low eyes, short, stout limbs o People would neotenized animal vs adult animal o Mickey Mouse over the years o Innate releasing mechanism neural network that is responsible for fixed action patterns or similar behavior sequences are produced by a neural network

Answer 31

Neotonization - the retention of juvenile features in the adult animal Potential human innate releasing mechanisms - neoteny features o People prefer babylike animals and things- ex. puppies, babies, kittens o Large Round head, large round low eyes, short, stout limbs o People would neotenized animal vs adult animal o Mickey Mouse over the years Innate releasing mechanism neural network that is responsible for fixed action patterns or similar behavior sequences are produced by a neural network

Answer 32

Explanation for preferences by females for males whose appearance signals that they are unlikely to carry disease or parasites Ex: Bower birds with high-quality bowers less likely to carry parasites in feathers

Answer 33

Preferences for certain male ornaments and courtship displays enable families to choose partners whose jeans will help their offspring develop mechanisms to combat infection and disease ex: cricket can evaluate strength of immune system through courtship display, cricket with song that conveys stronger IS Ex: large plumage sign of health and free from parasites-hard to grow and maintain when p present due to physiological stress Ex: peacocks with larger eyespots produced more offspring that survived better when released from captivity

Answer 34

ANALOGOUS: not related, similar traits due to similar environmental pressures ex: sugar glider and flying squirrel ex: vertebrate eye and cephlapod eye convergent evolution from different origins --- Homology traits that are similar to one another due to shared ancestry ex: common structure of the vertebrate limb divergent evolution from same origin

Answer 35

Phenotype: physical and behavioral traits Genotype:“blueprint” - genetic instructions present in an organism

Answer 36

the scientific study of animal behavior, especially in the natural context

Answer 37

- comparing traits and environments across taxa in search of correlations that test hypotheses about adaptation - if a behavior did arose from environmental pressure, then comparison of closely-related species subject to different pressures should yield different behavioral characteristics via divergent evolution - if behavior ex: gull mobbing

Answer 38

Independent variable varies naturally and dependent variable is measured to see if vary A affects B

Answer 39

the study of the evolutionary history and relationships among individuals or groups of organisms

Answer 40

sensory cue that triggers the behavior (red spot on bill) ex: Red herring Sign stimulus for chick = red spot on bright bil lSign stimulus for parent gull = chick’s pecking on bill

Answer 41

Tailfeather of widowbird an exaggerated sign stimulus (GIANT red spot on bright bill) ex: Oystercatchers were willing to roll huge eggs into their nests to incubate

Answer 42

(FAP) a stereotyped motor response that may be initiated by an environmental stimulus Chick’s FAP = pecking parent’s bill Parent’s FAP = regurgitating fish

Answer 43

sign stimulus that is emitted and received by the members of the same species

Answer 44

Redback spider Transferring sperm --> blocks female's sperm receptacles--> Somersault into mate's jaws - cannibalized males fertilized more sperm than non-c males did - partly due to female being less likely to mate again promptly - low likelihood of finding another mate - male genitalic pedipalps become broken or nonfunctional in course of initial mating - sexual suicide occurs when males have almost no chance of mating again

Answer 45

Sign stimulus: red spot on bill FAP: peck Sign stimulus: peck FAP: regurgitate fish

Answer 46

One male, one female ex: female satin bowerbirds female-enforced: burying beetle: pushes male from perch when he begins to release pheremones ex: yellow-eyed junco -- cares for young while mother incubates second group more likely to hatch with bi-parental incubation 97%, 75%

Answer 47

Male has several partners during breeding season ex: digger bees -- males copulate with several females, sometimes in a single morning

Answer 48

Female has several partners during breeding season ex: sandpiper females copulate with 2-3 mates per breeding season ex: honeybee -- using sperm from a dozen or so, copulate in midair

Answer 49

Genetic benefit to polyandrous females extra-pair fertilizations could reduce risk of female having an infertile partner as a social mate ex: red-winged blackbirds eggs of polyandrous red-winged blackbirds more likely to hatch eggs of monogamous red-winged blackbirds less likely to hatch ex: poly v. mono prarie dogs

Answer 50

Female preference for males who possess genes complementary to their own, heterzygous pseudoscorpion -- refused to remate with lone partners, prefered new mates; chance of obtaining gen-comp sperm increases with number of partners superb starlings -- went looking for males less

Answer 51

females gain material benefits (food presents, spermatophores) ex: megachild bee -- by mating with many mates, female megachild mates gain access to pollen and nectar in thise mates territories ex: the spermatophores of highly polyandrous butterflies contain more protein than monogomous species

Answer 52

males larger than females ex: male elephant seals - mating system is highly polygynous; a successful male is able to impregnate up to 50 females in one season - males can grow to 14 ft & 5,000 lb. while the females grow to 11 ft and 1,400 lb - body length - Copulation frequency is related directly to success in male-male competition, i.e., social rank - Pregnant females form dense aggregations called harems. The proximity of males to the female harem is determined by social rank, the higher ranking males being closest to the females ex: Red deer - Males take over harems by locking antlers & pushing other males - Males with larger antlers breed more than do males with smaller antlers - Males with larger antlers have lower survival rates than do males with smaller antlers. Weaponry confers mating advantage but survival cost.

Answer 53

Polyandrous females Monogomous males excess males, abundant food, precocial young

Answer 54

1. FERTILITY INSURANCE HYPOTHESIS Fertility Insurance Hypothesis: Genetic benefit to polyandrous females extra-pair fertilizations could reduce risk of female having an infertile partner as a social mate ex: red-winged blackbirds eggs of polyandrous red-winged blackbirds more likely to hatch eggs of monogamous red-winged blackbirds less likely to hatch ex: poly v. mono prarie dogs 2. GENETIC COMPATIBILITY HYPOTHESIS Genetic Compatibility Hypothesis Female preference for males who possess genes complementary to their own, heterzygous pseudoscorpion -- refused to remate with lone partners, prefered new mates; chance of obtaining gen-comp sperm increases with number of partners superb starlings -- went looking for males with less heterozygocity 3. MATERIAL GAINS HYPOTHESIS ex: megachild bee -- by mating with many mates, female megachild mates gain access to pollen and nectar in thise mates territories

Answer 55

1. FERTILITY INSURANCE HYPOTHESIS Fertility Insurance Hypothesis: Genetic benefit to polyandrous females extra-pair fertilizations could reduce risk of female having an infertile partner as a social mate ex: red-winged blackbirds eggs of polyandrous red-winged blackbirds more likely to hatch eggs of monogamous red-winged blackbirds less likely to hatch ex: poly v. mono prarie dogs 2. GENETIC COMPATIBILITY HYPOTHESIS Genetic Compatibility Hypothesis Female preference for males who possess genes complementary to their own, heterzygous pseudoscorpion -- refused to remate with lone partners, prefered new mates; chance of obtaining gen-comp sperm increases with number of partners superb starlings -- went looking for males with less heterozygocity 3. MATERIAL GAINS HYPOTHESIS ex: megachild bee -- by mating with many mates, female megachild mates gain access to pollen and nectar in thise mates territories

Answer 56

young born in relatively immature or helpless form - - require intense care ex: meadowlark

Answer 57

reproductive strategies available to living organisms semelparous = single reproductive episode before death ex: salmon iteroparous = multiple reproductive cycles over the course of its lifetime ex: pig Iteroparity - produce offspring in successive bouts - small # of young that receive intensive care - relatively low mortality rate of young

Answer 58

young can move about, feed themselves, and thermoregulate shortly after birth ex: ruffled goose

Answer 59

• expected value of future reproduction i.e., how many surviving offspring are you likely to have in the future? lower RRV = lower costs of parental investment factors: age, health, time of season

Answer 60

when an individual acts in a manner that temporarily reduces its fitness while increasing another organisms fitness organism acts in a way that temporarily reduces fitness while increasing another organisms fitness expecting the organism to do the same at a later time ex: baboons grooming one another

Answer 61

Host parents would accept and raise parasitic young to protect against predation by parasitic species ex: cuckoo will destroy magpie nest if gets rid of eggs

Answer 62

direct fitness: reproducing and rearing descendants, indirect fitness: assisting in rearing non- descent kin Direct selection- when a trait helps an organism sire successful offspring indirect/kin selection- an organism’s trait benefits other relatives (nephews, cousins, etc.) who have non-zero coefficients of relatedness

Answer 63

in Hamilton’s Rule, r, is the coefficient of relatedness —> which is the probability that 2 organisms share identical alleles because of common ancestry Hamilton’s Rule [ inclusive fitness] rB > C indirect fitness > direct fitness r=relatedness B=benefit to recipient for altruistic behavior C=cost of altruistic behavior Relatedness is the probability that two individuals share an allele due to recent common ancestry R ranges from 0 to 1

Answer 64

passing of genes from one generation to another in a successful manner

Answer 65

species tend to form lifelong breeding pairs, share a nest/home, guard against intruders together, and take care of offspring together

Answer 66

in most species, variability and reproductive success or reproductive variance is greater in male's than females Females invest more energy in producing offspring than males Consistent with theory of parental investment. In most species the females are a limiting factor

Answer 67

dopamine is involved in the formation of attachments.

Answer 68

Oxytocin and vasopressin have been shown to be involved in social recognition and pair bonding, .hormone released by the pituitary gland involved in pair bonding Oxt gene knocked out --> male cannot remember females; social amnesia ex: mouse F more sensitive

Answer 69

hormone involved in pair bonding and social recongition Prairie voles are monogamous; cells in male prairie vole brain bind with hormone vassopressin; produced and released into bloodstream when copulates several times with given female --> rewarding sensation less numerous v1a receptors in polygonous prarie voles lacking DNA in polyn that encodes for v1a protein receptor M more sensitive

Answer 70

symbiosis- close and consistent interaction between different species "the living together of unlike organisms" 1. COMPETITION - interactions in which both species experience costs ex: Cheetah and lions hunt for the same prey interacting in competition for gazelles and zebra 2. COMMENSALISM - interactions in which one species benefits and the other has no benefit or cost- no fitness difference ex: cattle egrets forage on insects that cattle disturb from the grass as they are grazing 3. MUTUALISM - interactions that benefit both species- increase fitness of both ex: oxpeckers remove ticks from animals that carry heavy tick loads and cannot remove them - Food for the birds and parasite removal for the larger animals - Oxpeckers spend more time foraging on impala ears and head than on other body parts because ticks are found at highest density on ears and head (74%of tick found) - Impalas scratch and groom less often when oxpeckers are present, which allows them to spend time grazing and looking out for predators Goby fish and blind shrimp depend on each other for food and shelterShrimp digs and maintainsburrow for both while gobywatches for predatorsShrimp’s digging stirs upfood for gobyShrimp keeps its antennaetouching the goby to know where burrow is and when predators arrive

Answer 71

symbiosis- close and consistent interaction between different species "the living together of unlike organisms" 1. COMPETITION - interactions in which both species experience costs ex: Cheetah and lions hunt for the same prey interacting in competition for gazelles and zebra

Answer 72

symbiosis- close and consistent interaction between different species "the living together of unlike organisms" 2. COMMENSALISM - interactions in which one species benefits and the other has no benefit or cost- no fitness difference ex: cattle egrets forage on insects that cattle disturb from the grass as they are grazing ex: Clown fish position themselves in poisonous anemones to protect themselves from predators-anemone does not sting them ; Anemonefish secrete mucous on bodiesthat protect them against anemone toxin

Answer 73

Interspecific mutualism- between species mutualism Intraspecific mutualism- within species mutualism symbiosis- close and consistent interaction between different species "the living together of unlike organisms" 3. MUTUALISM - interactions that benefit both species- increase fitness of both ex: oxpeckers remove ticks from animals that carry heavy tick loads and cannot remove them - Food for the birds and parasite removal for the larger animals - Oxpeckers spend more time foraging on impala ears and head than on other body parts because ticks are found at highest density on ears and head (74%of tick found) - Impalas scratch and groom less often when oxpeckers are present, which allows them to spend time grazing and looking out for predators - gobi fish and blind shrimp Goby fish and blind shrimpdepend on each other for food and shelterShrimp digs and maintainsburrow for both while gobywatches for predatorsShrimp’s digging stirs upfood for gobyShrimp keeps its antennaetouching the goby to know where burrow is and when predators arrive

Answer 74

Individual adjustment of sperm expenditure accords with sperm competition theory Intro: - sperm competition theory predicts that sperm expenditure should depend on the number of males competing to fertilize eggs - Risk model: sperm expenditure increases with competition between two males - compared to no competition - Intensity model: expenditure decreases with an increase in the simultaneous competition because of diminishing returns = strategic allocation of sperm among spawns - Fish are physically capable of controlling the sperm release but evidence in favor of the intensity model has not been generated - Study uses grass and black gobies in which there are territorial and sneaker males - thus there is a variable number of competitors naturally - Tested the risk and intensity models Methods: - Set up tank with a nest, territorial male, female, focal male and a range of sneaker males - Manipulated the number of sneaker males competing for fertilization of one nest (0, 1, 2, 4 added males) - Measured sperm expenditure of a focal sneaker male w/ varying number of competitors by sampling sperm in a standard amount of tank water Results: - Expenditure increases between 0 and 1 competitors but then decreases with increased # of competitors Discussion: - Results agree with theoretical predictions of risk and intensity sperm competition models - Except that if the territorial male is considered one of the competitors, then the model predictions are off by one male - Could be due to distance between males - sneakers may not have perceived competition with territorial male - Sperm allocation in spawning may be important because # of males changes over time - changing the chances being father!

Answer 75

Female African lions demonstrate a unique form ofplural breeding in which companions consistently produce similar numbers ofsurviving offspring. Consistent with theoretical predictions from models ofreproductive skew, female lions are unable to control each other’s reproductionbecause of high costs of fighting and low access to each other’s newborn cubs.A female also lacks incentives to reduce her companions’ reproduction, becauseher own survival and reproduction depend on group territoriality and synchro-nous breeding. Consequently, female relationships are highly symmetrical, andfemale lions are “free agents” who only contribute to communal care when theyhave cubs of their own. Intro: - Lion prides are well know to contain multiple breeding females - All births of lions in the Serengeti National Park between 1963 and 1999 have been documented - # of yearlings is measure of LRS - Maternity is known in 80% of cases and attributed in the other cases Methods: - Measured the variance in LRS across females and compared that to a random model of LRS - Measured time females spent alone before and after giving birth - Measured who (owners vs rivals) got access to certain parts of carcass during feeding - Measured cub survival as a function of pride size(# mothers) and other cubs' ages Results Females have surprisingly little reproductive skew Distribution of skews in real data is similar to the simulations of random skews Females give birth in secrecy and keep young away from pridemates for a few weeks Males that are larger supplant kill owners most often Owners keep control less often Females allow owners to keep the kill much more often Cub survival rate increases with increased # mothers- pride size Cub survival was highest when other cubs were same age - group rearing/nursing Discussion Females stay away from pride members when cubs are young and join in a creche rearing when cubs are older Females show significantly lower reproductive skew than males Despite significant weaponry, females do not fight for status or access to food Cub survival is correlated with cooperative care among mothers

Answer 76

receptor binding densities Dopamine, oxyticin and vasopressin receptor binding in the medial prefrontal cortex of monogamous and promiscuous prairie voles Intro: Monogamous= prairie, pine voles; mating pairs form bonds Promiscuous= montane, meadow voles; low levels of social affiliation Oxytocin and vasopressin have been shown to be involved in social recognition and pair bonding while dopamine is involved in the formation of attachments Females are more sensitive to oxytocin and males are more sensitive to vasopressin Methods - Comparisons between closely related species (prairie and montane voles) - Receptor binding o Uses radioactive form of the neurotransmitter or neuropeptide of interest to visualize the distribution of receptors in very thin slices of tissue o Quantified using mean gray scale, which is basically how dark/dense the film is where the neurotransmitter binds to the receptor, compared to where the neurotransmitter does not bind to the receptor " Done on sexually naïve males and females Results: " Prairie voles had lower densities of D1-like receptor binding and higher densities of D2 like receptor binding than meadow voles " Male prairie voles had the lowest desnity of D1-like receptors " Females had higher levels of oxytocin receptor binding than males and prairie voles had higher densities of oxytocin receptor binding than montane voles Discussion: " The prairie vole has lots of receptors- what parts of the brain respond to vasopressin and oxytocin

Answer 77

Bshary Interspecific communicative and coordinated hunting between groupers and giant moray eels in the Red Sea Introduction " True coordination in hunting requires that individuals play different roles during a hunt. " This has been demonstrated in some mammals and birds, but not fish. " The authors describe cooperative, interspecies hunting between two species of predatory fish in the Red Sea. " Grouper hunt in open water(pelagic zones) in day. " Moray eels hunt in reef crevices at night. " Hunting strategies are therefore complementary. " Hypothesis: groupers and moray eels hunt together and have greater success in shared hunts " Predictions: Two species spend more time near each other (duration and frequency) than is predicted by a random association model. " They signal each other to begin a hunt. " Prey catch rate is higher when grouper and eels are hunting together than when either is hunting separately. Methods " Groupers were followed/observed for 406 hrs. The proportion of that time spent in association with Moray Eels was calculated and compared to chance. " Chance was calculated using Waser's gas model, which predicts association durations based on independent movement. " Same was done for Moray Eels. " "Association" was defined by proximity of 10 m or fewer. Results " Individuals of the two species interact more than predicted by chance " Individuals of the two species remain in close proximity during a hunt " Groupers signal eels to initiate a shared hunt with headshakes and body/fin quivering " Groupers that are not hungry do not signal to eels. " Fed fish were never observed signaling. " Hunt success for grouper was higher than expected when with eel, lower when without eel. Discussion " This is the first demonstration of interspecific coordinated hunting in fish. " Both species hunt with normal strategies that happen to complement each other. " Possible that swallowing prey whole is key to success of relationship because competition over prey is minimized - no option for fighting or cheating.

Answer 78

Gelstein et al. (2011) Human tears contain a chemosignal Introduction: " Darwin suggested that tears evolved as an emotional signal " Other theories suggest that tears evolved as a eye-protecting adaptation, a mechanism for removing toxins from the eyes " Tears are composed on proteins, enzymes, lipids, metabolytes and electrolytes " But human emotional tears differ in chemical composition from reflexive eye-protective tears " Hypothesis: human tears convey a chemosignal between humans Methods " 1.Tested whether men could smell the difference between human emotional " tears collected from women and saline. " 2. Tested whether sniffing tears influences perception " Had men sniff jar of tears or saline and rate intensity, pleasantness and familiarity. " Placed pads containing tears below men's noses and had men view emotionally -ambiguous pictures of women's faces and rate sadness and sexual attraction. " Subjects also filled out a questionnaire that assessed empathy Results " 1.Perception of tears and o saline did not differ. " 2.Subjects rated sadness of o pictures the same while sniffing tears and saline " 3. Subjects rated faces as less sexually attractive while sniffing tears than while sniffing saline " 4.Sniffing tears while watching a sad film resulted in reports of lower sexual arousal than while sniffing saline and watching a sad film. " 5. Subjects' salivary testosterone levels decreased after sniffing tears and watching a sad film but not after sniffing saline and watching a sad film. " 6. In functional MRI, BOLD activity in brain regions related to sexual arousal was significantly lower in subjects who sniffed tears and watched sad films than in subjects who sniffed saline and watched sad films. Discussion " Tears as a chemosignal inhibit sexual arousal between male and female humans. " In Western culture, exposure to tears generally occurs in close proximity. Hence, the effects observed here are relevant to human behavior. " It is possible that tears in mammals in addition to humans serve as a chemosignals. " Are there signals in men's tears, children's tears?

Answer 79

A female-only lizard species gives birth without having had sex; each egg has a complete set of her mother's genes If a female-only species can thrive, are males necessary? The biological imperative to pass on genes Studying asexual and sexual reproduction in Sonoran minnows to demonstrate the value of males - sexually reproducing fish are more resistant to infestation with parasites - The Red Queen theory: when a species stops evolving, it is doomed - The evolutionary advantages of genetic variability among offspring Descriptions of sperm and eggs: quantity versus quality At a deep biological level, males and females want different things Darwin's theory of natural selection explained traits that improved species' survival, but not extravagances like the peacock's tail - Why are ornaments typically seen on males? - Ornaments as an indication of good genes - Male competition and female choice, as seen in peacock mate selection - In some species, females choose good behavioral traits or good genes - Monogamy as a social solution to a biological dilemma - female needs the male's help, but the male will stay home only if he believes the chicks he's helping to raise are his own - Female songbirds cheating on mates to give offspring better genes - Jacana birds and the reversal of male-female roles - -> So many chicks are lost to crocodiles that females leave their eggs for the males to raise, and go off to reproduce again - Gender roles determined by who competes for mates and who cares for young - Chimpanzee society is patriarchal and violent - Bonobo society is peaceful, due to female solidarity - Exploring how a change in feeding ecology influenced chimpanzee and bonobo differences - Implications for early humans, and humans today - Evolutionary psychologists' provocative theories about humans and our drive to reproduce - Research into human scent and genetic compatibility - Mate selection and the evolutionary roots of attractiveness - Did brains evolve, in part, to attract mates? - Humans have gone beyond the biological urge, and will raise children that do not share our genes

Answer 80

Sperm competition is LOW in chicken and quail. Males court females. Forced copulation is rare. Sperm competition is HIGH in ducks and geese. Multiple males mate with one female. Forced copulation is common. Differences in sperm competition and forced copulation have led to very DIFFERENT genitalia in these groups. ==>Males have long spiraled phalluses to deliver sperm and displace rival sperm.Females have vaginal tracts spiraled in opposite direction and blind pouches to make insemination difficult and to control which male fertilizes her eggs.

Answer 81

1. Predator defense (“selfish herd”) 2. Increase foraging by sharing information 3. Protection from the elements 4. Reproductive opportunities - mates are around! 5. Cooperative childcare, hunting Costs 1. Conspicuous to predators 2. Resource competition 3. Transmission of disease 4. Social stress 5. Increased brood parasitism, threats, infanticide

Answer 82

Primarily same-sex - Social dominance, agonistic behavior, affiliative behavior Primarily opposite-sex - Pair-bonding, Mating Parent-offspring - Pup retrieval, Licking and grooming

Answer 83

Syrian Hamsters - Solitary species - Highly aggressive - Flank marking behavior

Answer 84

Major urinary protein mouse social hierarchies dominant males produce more

Answer 85

Oxytocin and vasopressin = social recognition and pair bonding f- oxy, vaso- males dopamine = formation of attachments.