Exam 4 Flashcards

Question

Why is there a differential cost of reproduction?

Answer 1

commonly in the 2 sexes, 1 sex contributes more, large non-motile gamete (egg) while other makes smaller, usually motile gamete (sperm) *usually males gamete production has lower cost then when compared to females

Answer 2

every additional mate helps a male MORE than it helps a female, bc less costly for males to make sperm usually so beneficial for multiple mates

Answer 3

some males have many offspring, most have none, which places premium on mating success

Answer 4

Depends, but it is usually males bc depends on if can find a mate versus females who are restricted by birthing period, why we see a variance in male reproductive success

Answer 5

In monogamous species, there is a decrease in sexual pressure so there is a decrease in sexual dimprhism= less variance

Answer 6

members of sex subject to weak sexual selection=selection to be choosy/selection for attractiveness (intersexual selection) Members of the sex subject to strong sexual selection= selection to be competitive (intrasexual selection)

Answer 7

male-male competition occurs when individual males can monopolize females, either directly or through resources, or just can impress the female 1. Combat: weapons like antlers, horns, teeth, tusk help fight off other males and reproduce more, may fight over female or resource 2. Sperm Competition: sexual selection arises after mating when males compete for fertilization of a females egg ex: Deer mice competition @ sperm level 2. infanticide: improves males reproductive success but is detrimental to reproductive success of females 4. Alternative Strategies, like "Sneaky" Males: in many species males will adopt alternative strategies to mate, fish there are jacks which are smaller than larger males and look similar to females so males won't notice them so they can sneak into spawning areas and fertilize eggs * Can be more than 2 strategies, for example a marine isopod has 3 males (alpha-large and defend harem of females, beta males mimic females and sneak into harems, gamma males mimic juuveniles and "divebomb" harems to deposit sperm)

Answer 8

event, like fighting, determine reeproductive success involving interaction among SAME sex

Answer 9

key event that determines reproductive success involves interaction of the 2 sexes (male and female), can be morphological (phenotype/appearance) or behavior ex: Morpholigical: Bird of paradise have vibrant colors and huge tail, while it is energetically costly and may decrease overall fitness, males enjoy increased reproductive fitness and genes (of extravagance) are passed onto offspring Behavior: Bower Bird build intricate house and providee offerings to potential females mates

Answer 10

when females preference drives evolution of triat that becomes disadvantage to mates (like a train/tail of a peacock)

Answer 11

differential reproductive success due to variation among individuals in success of getting mates

Answer 12

energy and time expended constructing and caring for offspring, which investment measured by fitness (so more investment=increases reproductive success of offspring but decreases reproductive success for future

Answer 13

1. Sex creates new genetic variation and likely adaptive capacity 2. There is a differential costs of reproduction 3. Sex with greater variance in mating success will likely experience stronger sexual selection 4. Sexual selection can drive the evolution of traits that reduce fitness- ex: runaway sexual selection, male-male competition, even if lower suvivorship 5. selection for alternative mating strategies (example:sneakers)

Answer 14

ubiquitous but MOST obvious in species where males form leks (groups) ex: wild turkey lek, males have dangling snood

Answer 15

female preference can swamp suvivorship selection (ex: longer tail makes it harder for males to fly)

Answer 16

female preference must be heritable, female preference variation predicts assortative mating which generates the genetic correlation between female preference and male display assortative mating= continual preference for similar morpholoy

Answer 17

YES!!! runaway selection can kick in, female avg preference is for longer than avg males ex: female favors males, sons have linger tails and daughters prefer longer tails (depending on form of genetic correlation)

Answer 18

spermatophores (sperm-containing packages produced by male reproductive glands) ex: male fly gives gift, if gift small females eat it and move on so not full sperm transfer, if good size then mating more likely successful - female genes also gain advantage if they can predict how much male will help with child-rearing

Answer 19

variance in parental care

Answer 20

1. Monogamy - sexual monogamy-1 sexual partner for life - social monogamy- ex: bird pair mates for life socially, but female promiscuous 2. Polygyny: males attempt to mate with multiple females 3. Polyandry: females mate with multiple males

Answer 21

often coevolution betweeen male and female sexual conflicts include: 1. forced mating: usually causes great harm, water fowl forced mating has led to selective pressure for female defense, where reproductive organ spins opposite way of malee penis, pockets to hold male sperm and eject vs keep 2. spiky/shovel genitals: scrape out competing sperm ex:shiny phallus 3. Penis fencing, love darts: only hermaphroditic organisms like snails and flatworms, benefits the "giver" harms reciever (get stabbed) 4. sexual cannabalism: females eat males once mated 5. semen toxitcity: females sick after mating, benefits male cuz female will only mate with male, not attractive to other males (only toxic when MALES compete) 6. traumatic insemination: tears through abdomen/ female is greatly harmed

Answer 22

sex determination can be environmental or genetic - genetic: sex-determining chromosomes or genes (genetic sex determination, GSD) - --2 types of GSD: 1. male heterogamety: XY=males, XX=females (mammals;flies) 2. female heterogametry: ZW= female, ZZ=male (birds; butterflies) -environmental: temp-dependent sex determonation (TSD) or some plants start as hermaphrodites and change sex

Answer 23

- a gene on a Y that makes males fitter at the expense of females is favored (or W genes favoring females) - leads to an arms-race with X-linked genes spend a lot of time in females (or Z in males Dr. Pavitra research suggest that W-lined genes that caused females to pick males that carry sexually-antagonistic genes (good for females, bad for males) would increase in frequency if they result in very unfit males= decline in male survivorship

Answer 24

- many changes among polygamy, monogamy, polyandry | - sexual-signaling traits (exaggerated secondary characteristics) diverge rapidly

Answer 25

capacity for bacteria to cause disease and disease damage

Answer 26

population, all genes present in entire population core genes: in all individuals of population accesory genes: only some individuals in the population have it

Answer 27

most diseases attributable to small # of bacterial species

Answer 28

specific adaptation in Aas gene (adhesion gene) allowed staph to become virulent in humans and transmitted via humans, animals, indoor/outdoor environments, food; lateral gene transfer in M. abscesses dominant circulating clones, opportunities for LGT include soil + complex environment however deep tissue of mammal is pathogenic niche so harder for bacteria to gene transfer

Answer 29

traits that improve the success of a multi-individual group may be favored even if there are disadvantages so a gene that enhances group fitness can increase in frequency EVEN IF it lowers individual fitness

Answer 30

genetic tendency for organisms to help another (increasing their fitness) at their own fitness expense (individual fitness decease); for example, some altruists may give up the ability to reproduce themselves to rear other individuals' offspring (support survival and repoduction) *if one single group altruist freq will go down in next gen but if multiple sub groups (2 or more) then freq of altruists will go UP== means alturists can have lower fitness than non-alturists in EACH group but still have higher OVERALL fitness (when u add them up!!) this is an example of Simmons Paradox

Answer 31

groups compete, groups with more altruists do disproportionately better than groups with few

Answer 32

when organisms help one another ex: worker ants are sterile and help mother+sister reproduce

Answer 33

natural selection leading to spread of alleles that increase indirect component of fitness if beneficiary of an altruist act is close kin, then gene causing behavior can gain a net advantage (bc kin are more likely to also carry that gene)

Answer 34

under which altruism will increase in freq: Br-C>0=Br>C B=benefit to recipient C=cost to actor r=relatedness, 1/2 if full sibling, 1/4 if half sibling * inequality indicates altruism MORE LIKELY to spread when benefits to recipients are great and cost to actor is low and participants are closely related * personally costly behavior can evolve and increase in freq if benefit to kin is high enough * altruist traits tend to be directed towards kin, adopting kin enhances inclusive fitness

Answer 35

Direct fitness: results from reproduction an individual achieves on own, w/out help from related individuals Indirect fitness: results from additional reproduction by relatives that made possible by individual actions (Br-C) inclusive fitness is the SUM of both direct and indirect fitness

Answer 36

hypothetical alleles that cause individuals to recognize other carriers and act altruistically towards them , RARE bc requires 1 allele to generate 3 distinct phenotypees" the phenotype (beard), ability to recognize, and discriminating altruism ex: slime mold, are free-living organisms but under starvation they will come together to cooperate, this results in fruiting body (used as bridge) then slimes can go across but bridge left behind (altruist)

Answer 37

context of interactions determines likelihood of interacting with kin, selection COULD favor a gene that promotes altruism only torwards individuals u growth with

Answer 38

trend that appears in several independent groups of data reverses/disapears when groups combined=== i.e. alturists in group vs multiple groups!

Answer 39

many groups compete, group fitness if sensitive to degree of cooperation w/in groups, groups vary in proportion of cooperators and cheats, cooperation has genetic basis * group selection helped IF groups composed of kin, which increase variance among groups in proportion of cooperators (some groups have lots of cooperators, some will have lots of cheats)

Answer 40

kin selection implies intention and focuses on individuals carrying genes while group selection looks @ fitness of effects on genes on dif levels of organization, i.e. helps explain new levels of organization like multicellular organisms, bee colonies, etc.

Answer 41

a type of altruism, give up ability to reproduce for others | ex:bee colonies

Answer 42

can be caused by character displacement, assortative mating, pollinators, chromosome #

Answer 43

timing: individuals do not mate due to time of reproduction, selection promotes isolation of species pollinators: on landscape flowers attract dif pollinators behavior: bird calls, dancing, morphs attracted to each other

Answer 44

1. gamete incompatibility: usually via independent substitution, genetic drift, selection; no fusion of gamete 2. Zygotic inviability: fusion of gamete forming zygote but cannot develop into individual 3. ploidy difs can prevent production of viable hybrids, allows for allopolyploid hybrids * evolution of reproductive incompatibility requires mutation @ 2 or more loci

Answer 45

called speciation genes, often genes involved with immunity or sexual conflict

Answer 46

vicariance: when natural situation arises to physically divide organisms (ex: river) dispersal: founder event, subset of population moves to NEW location and establish itself there (usually more uncommon) ex: Hawaii islands filled with exotic wildlife through multiple lineage dispersals, why hi endemism:species found no where else on earth * sometimes we see repeated patterns of dispersal, ex snapping shrimp disperse from across panama canal so shrimp across panama are more related than shrimp living in the same location

Answer 47

1. Differential sorting of pre-existing allelic variation (like assortative mating after geographic isolation) 2. Dif mutations and selection regimes accumulate therefore, given allopatry evolution divergence is expected

Answer 48

is a process by which natural selection increases reproductive isolation can occur when: When two populations which have been kept apart, come back into contact, the reproductive isolation between them might be complete or incomplete. (post-mating but not pre-mating isolation) If it is complete, speciation has occurred. If it is incomplete, hybrids would be produced. * selection favors alleles that promote assortative mating (avoids wasted mating opportunities)

Answer 49

1. grouping: deciding which groups are taxa 2. ranking: deciding which taxa are species, genera, etc. * ranks established by convention so NOT objective

Answer 50

species unit of taxonomy, part of hierachical of named groups, products of evolution * phylogenetic concept is now the basis for designating species as it provides objective grouping criterion and does not provide an objective ranking criterion

Answer 51

populations or sets of linked populations, players in evolution

Answer 52

is a circular arrangement of populations with one boundary characterized by reproductive isolation, but intergradation among populations elsewhere. "species complex" illustrates that distinct forms in sympatry could be parts of 1 continuous cline

Answer 53

Hybrid zones are locations where hybrids between species, subspecies, or races are found. Typically, hybrid zones are described as clines, spatial gradients in traits or alleles across a geographic transect where two taxa meet.

Answer 54

one of two or more morphologically indistinguishable biological groups that are incapable of interbreeding , co-occur in sympatry but have very similar morphology