Exam 3, Modules 8 - 13 Flashcards
Communication signals are believed to have evolved via what three hypotheses/theories?
- preexisting biases
- preexisting traits
- panda principle
__ __ hypothesis states traits that already provide informative cues to receivers, and if the sender benefits from the receiver’s response as a result of these cues, then the cue can be modified into a __ via a process called __.
Preexisting traits
signal
ritualization
__ __ theory explains how biases in sensory systems (that detect some features of the world better than others) can be __ by sender signals in a process called sensory __.
Preexisting bias
exploited
exploitation
The __ __ states that traits, such as the waggle dance, may have evolved from __-__ movements that alerted foragers to food, but did not provide direction or distance. “__ is a tinkerer, not an engineer”.
panda principle
less-sophisticated
Evolution
A female water mite grabs a male like she would prey because he vibrates water the way prey would.
Female guppies seek males that produce orange pigment because they prefer carotinoid-containing foods.
Male noctuid moths that use ultrasonic sounds (like a bat) to attract females.
These are examples of?
Sensory exploitation of preexisting bias
Piloerection is a thermoregulatory response that has been __; in other words, it was a preexisting __ that benefited the sender due to the receiver’s response.
ritualized
trait
Name and briefly describe he three hypotheses that might explain the adaptive value of the spotted hyena’s pseudopenis.
- By-product hypothesis: the pseudopenis isn’t itself adaptive but evolved as a result of another adaptation, such as high testosterone (and the benefits that come with dominance).
- Submission hypothesis: pseudopenis signals subordination or willingness to bond; evidenced by subordinates displaying pp to dominants, first.
- Social Bonding hypothesis: pseudopenis sniffing promotes cooperative coalitions which may raise fitness
~Stiff-legged strut by female spotted hyenas communicate aggression; females might submit rather than costly fight.
~Male impalas snort and shake horns which presents opportunity to size each other up which may avoid fight.
Both are examples of?
Honest signaling.
Honest signals can be enforced via what two ideas?
- production costs – cost associated with an expensive signal.
- Maintenance costs – cost of maintaining a signal due to social enforcement. Usually the signal itself isn’t costly in which case it’s called a badge of status (as in female wasps with black mark).
__ __ is the fine-tuning of signals to work effectively in a particular environment (evolutionary).
Sensory drive
When is sensory drive important for signal evolution?
When the constraints on the signaling environment are extreme.
Why are alarm calls given by different species of birds hunted by hawks are so similar?
Calls at a certain frequency can warn legitimate receivers very nearby, but weakens quickly so that the hawk can’t hear… convergent evolution!!!
__ __ is the process by which complex behavioral patterns evolve gradually from less complex behavioral patterns through long and slow accumulation. Also known as this principle.
Cumulative selection
Panda principle.
Darwin’s theory of descent with modification tells us what about the adaptive traits of extant species?
Adaptive traits are the products of past changes layered on still older changes that occurred during the history of the species.
This is the process whereby novel communication signals can originate when signalers possess a mutant attribute that turns on a sensory preference that had evolved for other purposes.
Sensory exploitation
Female birds dig male birds that were given artificial crests. What explanation might be given for this behavior?
Crest activated a preference due to preexisting bias for trait (LCA had a crest).
The femme fatale firefly is a species of firefly that sends __ signal to a male that is flashing a pattern to attract females (she is __), and eats him when he flies to her; this is an example of __ signaling using a __ __.
deceptive
eavesdropping
deceitful
sensory trap
Name and describe the 2 hypotheses to explain maladaptive behavior of male fireflies with the femme fatale firefly.
- Novel environment hypothesis: the current environment changed too fast (humans), and the males haven’t adapted yet.
- Net benefit hypothesis: the sensory mechanism resulting in fitness losses doesn’t outweigh the average fitness gains provided by the mechanism (avoiding females could lead to greater losses).
Unintended receiver of purposeful communication signals is this.
Illegitimate receiver
The detection of signals from a legitimate signaler by an illegitimate receiver (to the detriment of the signaler and the benefit of the receiver) is known as this.
Eavesdropping
~Storks use dance to reinforce pair-bonds and stimulate ovulation.
~In monogamous siamang primates, duetting is performed to advertise territory.
Both are examples of what type of communication?
reproductive communications
A form of communication where the male and female participate to maintain pair bonds (such as in plan wrens and siamang primates) is called this.
Duetting
Foragers performs waggle-runs by shaking what? The duration and orientation contain info about what? A longer waggle-run means what?
her abdomen
the distance and direction to food
The more distant the food.
What does a forager bee use to convey direction outside the hive? In a dark hive?
Outside the hive: horizontal surface using the sun’s position to orient direction (sundial).
Inside: a vertical surface using gravity
An informative cue from a sender to a receiver where the sender benefits, so the cue is modified into a signal is called this.
ritualization
Communication systems are the result of what two phenomenon?
Cumulative selection and sensory exploitation.
Multiple communication signals used simultaneously is called this.
a. redundant signaling
b. Pluripotent signaling
c. Multimodal signaling.
d. degenerate signaling
Multimodal signaling.
A __ communication signal is a “backup” that increases its robustness (often through repetition)
A __ signal increases the robustness and functionality of the signal, often with “two components serving similar functions”.
A __ signal in which one structure serves “multiple” functions, something that can increase signaling efficiency.
Redundant
Degenerate
Pluripotent
When a peacock spider uses his fan display and vibrates abdomen to produce sound, are these multiple messages, or are they redundant signals.
They can be either!
The ratio of sexually active males (or females) to sexually receptive females (or males) is known as this.
Operational sex ratio
If there is a male biased operational sex ratio, what does each sex demonstrate with respect to:
Parental investment
Reproductive rate
Sexual activity
Parental investment males = low, females = high
Reproductive rate males = high; females = low
Sexual activity males = high; females = low.
How does a male-biased operational sex ratio influence male and female behavior?
Males:
compete for mates (intrasexual selection)
Elaborate traits (intersexual selection)
Fitness benefits - More mates = more offspring
Females:
Choosy (intersexual)
Fitness benefits - better mate quality and healthier offspring
Intrasexual selection produces what kind of behavior? Intersexual?
Intra = competion
Inter = ornaments (physical or behavioral as in songs, dance, etc.)
Which forms of sexual selection impact ornaments and armaments?
Ornaments: intersexual selection (look at me)
Armaments: intrasexual selection (fight me)
What kind of sexual structure yields the following:
*Potential mates “both” engage in courtship displays.
*Both sexes are choosy
*Pair bond is formed and reinforced with displays
monogamy
The fusion of two gametes that differ greatly in size is this.
Anisogamy
Given that, in general, female reproductive success is dependent on mate quality while male reproductive success is dependent on number of mates, what theory describes how these two points will yield higher variance in males?
a. Hamilton and Zuk hypothesis
b. Hamilton’s rule
c. Bateman’s principle
d. Trivers-Willard hypothesis
c. Bateman’s principle.
In general, female’s reproductive success is far more dependent on the quality of her partner than on the number of males she mates with. Sperm are cheaper than eggs, so male’s reproductive success is limited by the number of mates. How does this impact reproductive success on males (vs. females)? What principle is this?
Males have higher variance in reproductive success (they may get all the babes or none).
Bateman’s principle.
Unequal partitioning of reproduction within a population or social group is known as reproductive __.
skew
This theory argues that eggs are expensive but sperm are cheap hence why male-biased operational sex ratio is the norm in most species.
a. Reproductive skew
b. Bateman’s principle
c. Fundamental asymmetry of sex
d. Sexual conflict
Fundamental asymmetry of sex
The cost associated with parental activities that increase the likelihood of survival for (some) existing offspring but that may reduce the parent’s future reproductive success is called this.
Parental investment
List 3 examples of sex role reversals.
- pipefish
- empid flies that hunt for nuptial gifts, then choose females with the fanciest wings and legs.
- During lean times, male Mormon crickets that produce a spermatophore (high energy, can only mate once) and choose largest females.
This type of social organization is where conflicts are not about an immediate mating opportunity, but about establishment of pecking order, then access to mates.
dominance hierarchy
T or F: dominance hierarchies do not have a major impact on sexual dimorphism.
F: produce extreme sexual dimorphisms as in the size difference between male and female elephant seals.
Are conditional strategies polymorphic or polyphenic?
They can be either as in bluegill fishes (polyphenic contingent on environment during critical period of development) or as in side-blotched lizards with alphas, betas, and gammas (polymorphic).
Scorpion flies have a caste where the largest males defend dead insects to attract mates, medium males secrete salivary gift, and small males force matings. When the largest is removed, small and medium males “graduate” to higher caste. What kind of conditional strategy is this?
Socially-dependent conditional strategy
Smaller male frogs/toads will stay near the largest male waiting for him to “call” females to him, then sneak in. What is the name of this behavior?
Satellite or sneaker behavior
Rove beetles, medium bluegill (1 of 3 forms), gamma marine sponge isopods (1 of 3 forms); and yellow side-splotched lizards (1 of 3 forms) engage in this to sneak past alpha males.
female mimicry
The side-blotched lizard has three forms (orange, yellow, and blue) that has been compared to rock-paper-scissors. Explain.
Orange beats blue because they are polygynous and territorial, so they bully and steal blue’s mate.
Yellow beats orange by mimicking unreceptive females and chasing him away from real females.
Blue beats yellow by mate guarding since they are monogamous.
What kind of selection acts on the three polymorphic forms of the side-blotched lizard? From an evolutionary standpoint, what kind of strategy is it?
frequency-dependent selection
evolutionarily-stable strategy
Polyphenic __-__ morphs are determined during critical period of development (bluegill); or by social environment and have behavioral plasticity (scorpionflies, baboons). Which morph is the most fit?
Condition-dependent
Equal fitness
The genetically based capacity of an individual to use different mating tactics under different environmental conditions; the inherited behavioral capacity to be flexible in response to certain cues or situations. Also name aka.
conditional mating tactic (aka Conditional strategy with alternate mating tactics)
A type of behavioral polymorphism that has a strong genetic component and is therefore inflexible and fixed throughout an individual’s life.
Alternative mating strategy
Alternative mating strategy vs. Conditional strategy with alternate mating tactics?
Alternative mating strategy: very strong genetic component with inflexible behavior.
Conditional strategy with alternate mating tactics: genetic component enables behavioral plasticity.
Subordinate male baboons will befriend females and help rear young. This increases the probability of the female seeking him out during her next estrous. What kind of strategy is the male employing?
Conditional strategy with alternate mating tactics (or conditional mating tactics) utilizing alliances / friendship.
A mating by a male or female with an individual other than his or her partner in a socially monogamous species.
Extra-pair copulations
Female choice includes direct and indirect benefits. Label the following as an indirect or direct benefit.
1. parental care
2. good genes
3. protection (from predators or harassing betas)
4. access to resources
- direct
- indirect
- direct
- direct
What three circumstances lead to sexual suicide?
- Females are extremely rare / hard to find (redback < 20% locating rate).
- Cannibalized males fertilize more eggs (increased female fecundity).
- Females might be less likely to mate immediately afterward.
What hypothesis states male self-sacrifice can enhance fertilization success if it means females are less likely to mate again?
a. Sexual suicide hypothesis
b. Mate guarding hypothesis
c. Paternal assurance hypothesis
d. Mate limitation hypothesis
Sexual suicide hypothesis
Testosterone stimulates the development of traits used in sexual selection, but it also reduces immunocompetence; therefore, testosterone-dependent signals may honestly advertise health to females (ability to overcome drawbacks). What hypothesis is this?
Immunocompetence handicap hypothesis
This hypothesis explains that when female mating preferences for certain male attributes create a positive feedback loop favoring both males with these attributes and females that prefer them.
Runaway selection hypothesis of sexual selection
An antagonistic coevolutionary relationship between males and females in which some male traits that attract females may actually be disadvantageous to the female. In this model, females become ‘resistant’ to male traits (due to their disadvantage), so traits become more pronounced to overcome resistance, and so on. Name the hypothesis and list an example.
chase-away selection model of sexual selection
Ex: fruitfly females that prefer larger males to her detriment.
In internal fertilization, females of some species can eject sperm or ovarian fluid. In the latter, females eject sperm quantity while enhancing more capable sperm (quality). Additionally, females of some sp. will invest more in offspring from preferred males and less if the opposite is true. They can also lay larger or more eggs. What is this phenomenon called?
Cryptic female choice
Conflict between males and females over mate choice is called?
sexual conflict
~Bedbug males inject sperm into bloodstream. Females mating at high frequencies die sooner (but those who average 3 mates per week experience greater fecundity).
~Most water birds are monogamous, so males have developed funky penises to overcome female choice in extra-pair copulations. Females have developed elaborate vaginas that run clockwise (opposite) and have false ‘ends’ in response.
~Infanticide forces females to go back into estrous. Females may “win by losing” if new male(s) are stronger/more fit.
What are these examples of?
Reproductive/sexual arms race
This term refers to an adaptation that appears during infancy to serve an immediate need for the infant
Transient ontogenetic adaptation
This competition increases with the degree of polygamy and communal spawning.
sperm competition
Which of these is not an example of sperm competition?
a. Large bluegill have more sperm, but sneakers that get past large males get closer to eggs and have more success.
b. Damselfly males have a scrub-brush penis that removes stored sperm from females.
c. Faster individual sperm.
d. Cooperative sperm that recognize self or close kin and swim faster in aggregates.
e. non of the above
e. non of the above
Preferences for certain male ornaments and courtship displays enable females to choose partners whose genes will help their offspring have higher fitness. What construct explains this?
good genes model of sexual selection
In this theory, scientists posit that the expression of particular male traits (plumage, cricket songs, etc.) is associated with resistance to parasites or other pathogens. Resistant males should be healthier and be better able to express the trait.
a. Hamilton and Zuk hypothesis
b. good genes model of sexual selection
c. Bateman’s principle
d. Trivers–Willard hypothesis
Hamilton and Zuk hypothesis
Females may be able to detect heterozygosity, esp. in genes that are critical for health, such as the major histocompatibility complex (MHC) which is critical for immune system function in recognition of foreign antigens. What construct explains this?
a. Immunocompetence handicap hypothesis
b. inbreeding avoidance
c. good genes model of sexual selection
d. Hamilton and Zuk hypothesis
b. inbreeding avoidance
Distribution of resources, distribution of sexes, necessity of parental assistance, mate guarding, and limitations on breeding capacity are all reasons for what?
variations in mating systems.
Which mating system leads to male-biased operational sex ratios? Female-biased?
Polygyny
Polyandry
What’s the difference between Polygynandry and Promiscuity?
Polygynandry: males and females form multiple pair-bonds.
Promiscuity: males and females mate with several partners but do not form pair-bonds.
A form of polyandry in which a female will struggle with a male but acquiesces to his mating attempts in order to save time and energy.
Convenience polyandry
Female ring-tailed lemurs have asynchronous estrous cycles leading to what kind of mating system?
Polygynandry
Social monogamy vs. genetic monogamy?
*Social monogamy: pairing of a male and female, but extra-pair copulations may be taking place.
*Genetic monogamy: pairs produce and rear their own genetic offspring.
When multiple mating has more costs than benefits, what type of mating system is likely to occur?
a. alternate mating strategy
b. conditional strategy with alternate mating tacticts
c. monogamy
d. promiscuity
c. monogamy
Name 5 hypothesis to explain monogamous mating systems.
- Mate guarding (keep female from mating)
- Mate assistance (increased offspring survival)
- Female enforced monogamy (mate guarding)
- Mate limitation (mates are rare, leads to mate guarding behavior and monogamy as consequence).
- Infanticide (when risk of infanticide is high, offspring guarding leads to monogamy as in female lions).
Female burying beetles will knock males off perch if they signal to other females (mate guarding by female to increase parental assistance of male). What monogamy hypothesis explains this?
female enforced monogamy
~Monogamous sea horse: males carry fertilized eggs and can only accommodate one clutch at a time. When eggs hatch, his mate is ready w/ more eggs.
~California mouse and voles: more offspring survive is male remains than if removed.
~Most bird species: females rearing alone (widowed) have offspring with reduced survival rates.
What monogamy hypothesis explains these?
Mate assistance hypothesis
There are indirect genetic benefits females receive from being polyandrous. Name 4 hypotheses that explain the behavior.
- Good genes hypothesis: being polyandrous may produce better offspring.
- Genetic compatibility hypothesis: increase the odds of receiving genetically complementary sperm.
- Genetic diversity hypothesis: increase heterozygosity.
- Inbreeding avoidance hypothesis: limited dispersal opportunities (red-backed fairy wrens).
List 3 hypotheses that explain direct benefits for polyandry.
- Additional resources hypothesis (extra spermatophores, foraging privileges, etc.).
- Additional care hypothesis (from additional males as in galapagos hawks).
- Infanticide avoidance hypothesis (creates uncertainty about paternity).
T or F: dunnocks have behavioral plasticity and employ multiple mating strategies (polygyny, polygynandry, and monogamy) contingent on social and ecological factors (conditional strategy).
True!
What are the 4 main types of polygyny?
- Female defense hypothesis
- Resource defense hypothesis
- Lek polygyny hypothesis
- Scramble competition hypothesis.
This polygynous hypothesis explains that when resources are evenly distributed, but females form groups to better access those resources or to help dilute the risk of depredation (or infanticide as in lions).
Female defense hypothesis
This polygynous hypothesis explains that when resources are patched or clumped, males will claim the territory and gain access to females passing through.
Resource defense hypothesis.
Name the polygynous hypothesis:
When resources are distributed heterogeneously and females are widespread and do not form groups, males will wait for females to come to them.
Lek polygyny hypothesis
Name the polygynous hypothesis:
When resources are distributed heterogeneously and females are widespread and do not form groups, males will seek out females.
Scramble competition hypothesis
Scramble competition polygyny versus lek polygyny hypotheses.
Both have females and resources that are widely distributed, but scramble competition males seek out females; lek polygyny males wait for females to come see their show.
The hotshot, hotspot, and female preference hypotheses all attempt to explain what type of mating system?
lek polygyny.
~Male baby elephant seals attempting to sneak milk to be larger as adults.
~Cukoos ejecting eggs and holding their mouths open longer to avoid injuring host parents.
These are both examples of?
Transient ontogenetic adaptation
Name 3 hypotheses to explain how offspring induce variation in parental care and what influences care.
- Signal of need hypothesis - honest signal of need.
- Signal of quality hypothesis - honest signal of reproductive value.
- Dishonest signaling - half-siblings or fierce competition
Altricial vs. precocial
Altricial = stays in nest for a long period
precocial = born ready
Term:
Parental strategy where the most competitive siblings are more likely to survive and reproduce.
Why did it evolve?
sibling conflict
Evolutionary conflict resulting from divergent interests among current and/or future siblings.
Term:
Behavior that results in an individual killing a sibling or siblings.
Why did it evolve?
siblicide (siblicidal behavior)
May have evolved because of the fitness advantages gained by offing siblings and gaining more resources (food).
Nazca booby parents ignore siblicidal behavior. This is an example of what?
obligate siblicide
Blue-footed booby parents supervise more closely Than Nazca boobies. Siblicidal behavior is diminished when food is available; increased when food is scarce. This is an example of what?
facultative siblicide
The __ __ hypothesis states that mothers
in siblicidal species lay a second egg as insurance against hatching failure (e.g., Nazca boobies).
reproductive insurance
Term:
Evolutionary conflict arising from differences in optimal parental investment in an offspring from the standpoint of the parent versus that of the offspring.
Parent-offspring conflict
The local competition hypothesis, local enhancement hypothesis, and Trivers-Willard hypothesis all attempt to explain:
a. parent-offspring conflict
b. variation in sex-ratios of offspring
c. offspring reproductive value
d. reproductive insurance
b. reasons for variation in sex-ratios of offspring
This hypothesis predicts that healthy mothers should produce the sex with higher variation in reproductive value, but mothers in poor condition should produce sex of lower variation in reproductive value.
a. Hamilton and Zuk hypothesis
b. Trivers–Willard hypothesis
c. Hamilton’s rule
d. Bateman’s principle
b. Trivers–Willard hypothesis
St. Peter’s tilapia are mouth brooders where either sex can incubate the eggs and young. Either sexes potentially loses weight as a result of mouth brooding. Who incubates, and why?
Cost to males = negligible reduction in sperm production.
Cost to females = longer interspawn interval
Much lower cost to males, so they normally mouth brood. NOTE: could be female preference for paternal males due to fecundity costs!!!
What hypothesis explains under what conditions we are likely to get paternal care?
What else might explain paternal care?
Paternity assurance hypothesis - males who know they’re the father are more likely to provide care.
When the cost to females is much greater and negatively impacts offspring (smaller/fewer eggs, low survival, etc.).
Explain the variation in blue gill paternal care (experiment from Box 11.2)
Male bluegills were less protective of eggs when rival males were placed near eggs. As cuckholding potential increased, parental care decreased (due to potentially reduced reproductive fitness). [Paternity assurance hypothesis]
Name the theory:
Hosts accept brood parasitic eggs out of fear of retaliation by the brood parasite for destroying its eggs.
Mafia hypothesis for brood parasitism
Term:
When two parties in conflict exert reciprocal selection pressure on each other, with an adaptive advance made by one often leading eventually to an adaptive counterresponse by the other.
coevolutionary arms race
Explain the example of the coevolutionary arms race between the superb fairy wren and the cuckoo.
Wren: sings password to unhatched eggs, and chicks must sing it to get fed.
Cuckoo: egg mimicry, gape mimicry (similar reflectance properties), mimicry of begging calls/behavior (supernormal stimulus)
What types of supernormal stimuli do cuckoo chicks provide to host parents?
Tree nesters = sound spectrogram similar to a whole nest of chicks (get fed more).
Ground nesters = silent, but raises wing to mimic second gape.
List 2 hypotheses that explain the evolution of interspecific brood parasitism.
- Gradualist shift hypothesis - started as intraspecific brood parasitism.
- Sudden shift - no intermediate steps.
Currently, whydahs and indigobirds parasitize closely related finches in Estrilididae (they share similar egg pattern and hatchling begging behaviors). What hypothesis might this be evidence for?
Gradualist shift hypothesis
Name the hypothesis:
Regarding nest parasitism, parasites might have been larger than host species, which exploits parental preference for larger, higher quality offspring. An experiment with great tits and blue tits supported this hypothesis.
Sudden shift
Term:
behavior that seems to lower fitness (reproductive success) while increasing the fitness of the individual being helped
altruism
Term:
Probability that an allele present in one individual is also present in another due to a recent common ancestor.
Coefficient of relatedness (r)
The Coefficient of relatedness (r) is a key concept for what?
kin selection
List the (r):
1. Parent/offspring
2. Siblings
3. Aunt/uncle
4. Great aunt/uncle
5. 1st Cousin
6. Grandparent
7. Great grandparent
8. ID twin
1) 0.5
2) 0.5
3) 0.25
4) 0.125
5) 0.125
6) 0.25
7) 0.125
8) 1.0
Name the type of selection:
~Hereditarily distinctive individuals differ in the number of surviving “descendant kin” (offspring) they produce.
~Hereditarily distinctive individuals differ in the number of “non-descendant” kin they help to survive to reproduce.
Direct selection
Indirect selection
Direct vs indirect fitness
Direct fitness: measure of the reproductive / genetic success of an individual based on the number of its offspring (descendant kin) that survive to reproduce.
Indirect fitness: measure of the reproductive / genetic success of an individual based on the number of its non-descendant kin that the altruist helps to survive to reproduce that would not have otherwise survived to do so.
Term:
Describes species with overlapping generations, cooperative care of young, and reproductive division of labor where many individuals in a group are permanently sterile.
eusociality
Theory:
social attributes, including altruistic behavior, evolved to benefit the species or the group as a whole
Group selection theory
Term:
The process that occurs when groups differ in their collective attributes and these differences affect the survival chances of the group
Group selection
Williams proposed this theory which explains that helping non-descendant kin (i.e., non-offspring kin) can provide an indirect route to making a trait more common (fitness is contingent on survival of both descendant and non-descendant kin).
Which theory was this in opposition to?
kin selection theory
Group selection theory
Term:
Selection that occurs when hereditarily distinctive individuals differ in the number of descendant and non-descendant kin they help to survive and reproduce.
Kin selection
Term:
The total measure of an individual’s contribution of genes to the next generation by both direct and indirect fitness.
inclusive fitness
Term:
development from an unfertilized egg (as in male Hymenoptera).
Parthenogenesis
This term is derived from kin selection where altruistic behavior benefits individual fitness.
individual selection.
Term:
The argument made that altruism can spread through a population when rB > C
Hamilton’s rule
What is the formula in Hamilton’s rule?
rB > C
(r) = coefficient of relatedness
B = fitness (b)enefit received by the helped individual
C = the (c)ost of altruism in terms of the direct fitness lost by the altruist’s actions.
Term:
sex-determination system in which males develop from unfertilized eggs and are haploid, and females develop from fertilized eggs and are diploid.
Haplodiploidy
Term:
cell / organism with only one set of unpaired chromosomes
Haploid
What hypothesis explains the evolution of eusociality?
Monogamy hypothesis
Why might monogamous queen bees have lead to the evolution of eusocial colonies?
They’re a haplodiploidy species, so the drone’s sperm are all clones making the sister workers’ relatedness of 0.75.
Reproductive conflict in eusocial species includes what two phenomenon?
- Worker policing - workers eat/remove eggs of another worker (only the queen can have eggs).
- Reproductive conflict - conflict over who gets to breed and resources needed to breed.
Term:
The synchronized movements of individuals following a series of basic interaction rules (as in a pack of hunting wolves).
Collective behavior
Increase resource competition, time/energy maintaining hierarchy, vulnerability to cuckholdry, greater transmission of disease/parasites, breeding interference (kicking out eggs of others), and increased conspicuousness to predators are all costs associated with what?
Social living
Improved protection (selfish herd); more eyes to forage/hunt; more muscle to kill prey; increased reproductive fitness for subordinates (via cuckholdry); help with parasites; and huddling for warmth are all benefits associated with what?
social living
How was group selection theory used to explain altruism?
Helpful behavior was explained as existing for the benefit of the group; evolved as group selection.
List the 4 types of social interactions based on fitness payoffs in terms of losses and gains.
- Mutual benefit: (aka, mutualism) - [donor / recipient = +/+]
- Selfishness: (aka deceit or manipulation)[donor / recipient = +/-]
- Altruism: [donor / recipient = -/+]
- Spite: [donor / recipient = -/-]
Mutual benefit vs. kin-selected benefit
*Mutual benefit = when an individual eventually gains access to a resource controlled by another individual because of its prior help, it is called postponed cooperation. (manakins)
*Kin-selected benefit = raises kin-directed (indirect) benefits
cooperation vs. reciprocity vs. altruism
Cooperation = both help each other. Helper gains direct fitness eventually; helped gains direct fitness.
Reciprocity = helper looses direct fitness but gains it back when helped “pays back”; helped gains direct fitness.
Altruism = helper sacrifices direct fitness to gain indirect fitness; helped gains direct fitness.
Explain how behaviors that seem to put an individual at risk (e.g., alarm-calling) can evolve.
Improves either direct fitness by protecting offspring, or indirect benefits (kin selection of non-descendant kin).
Provide examples of interspecies social interactions for parasitism and mutualism
parasitism = cuckoo
mutualism = reef cleaner fish
In long-tailed manakins, beta male has increased probability to become alpha and inherit the lek. What kind of benefit is this?
delayed direct benefit
Term:
A helpful action that is repaid at a later date by the recipient of the assistance.
reciprocal altruism (aka reciprocity)
What happens if a “defector” shows up in a population of reciprocal helpers?
It would exploit helpers, so reciprocity would be less likely to evolve.
Prisoner’s dilemma: why is cooperation not the best strategy?
cooperation between the players generates a lower return than defection
Fitness payoff: “defect while other player cooperates” > “both cooperate” > “both defect” > “cooperate while other player defects”
Regarding the prisoner’s dilemma, how can we get cases of reciprocity if that is not best strategy?
In prisoner’s dilemma, players meet only once. However, when a relationship is established, individuals use the tit-for-tat rule (do unto others); the rewards for reciprocity add up and benefits eventually exceed defection.
The following 3 hypotheses attempt to explain evolution of cooperative breeding. Describe each.
1. kin selection hypothesis
2. group augmentation hypothesis
3. ecological constraints hypothesis
- kin selection hypothesis - individuals delay independent breeding and become nonbreeding helpers (indirect fitness).
- group augmentation hypothesis - individuals survive or reproduce better by living in larger groups (plural breeding).
- ecological constraints hypothesis (habitat saturation) - if resources are limited, individuals will delay dispersal and remain help raise their relatives (indirect fitness).
A form of cooperative breeding system in which social groups contain more than one breeder of at least one sex
plural breeding
A form of cooperative breeding system in which social groups contain only one breeder of each sex.
singular breeding
A social system in which more than two individuals care for young.
Cooperative breeding
What two theories explain some of the main reasons for polygynous mating systems?
a. Intersexual and intrasexual selection
b. Dominance heirarchy and Inbreeding avoidance
c. Infanticide avoidance and female defense
d. Female distribution and female social structure
d. Female distribution and female social structure
