Q&A Hero

Q: Redirected aggression refers to a. deception during aggressive episodes to deflect an aggressor toward another individual. b. turning received aggression back onto an aggressor. c. responding to a threat by attacking a lower-ranking individual who was not involved in the original incident. d. an ability only humans have.

Q: In a playback experiment in which female baboons listened to a recording of a female's grunt followed by another female's submissive fear barks, a. females responded more strongly when they heard a higher-ranking female responding submissively to a lower-ranking female's grunt. b. females responded more strongly when they heard high-ranking females in conflict with each other. c. females reacted to each vocalization regardless of the rank of those making the call. d. females only reacted to the vocalizations of female kin.

Q: Playback experiments of vervet monkeys show that a. males can recognize their offsprings' vocalizations. b. mothers recognize the call of their own offspring and one another's offspring. c. offspring recognize the calls of their mothers. d. all group members respond to calls of juveniles.

Q: To understand third-party relationships, a primate musta. have knowledge of the nature of relationships among other individuals.b. live in a large group.c. be able to predict food distribution in an environment.d. understand the reproductive rates of other primates.

Q: Which of the following hypotheses does not explain ape brain size well?a. The arboreal hypothesis b. The social intelligence hypothesis c. The ecological hypothesisd. The executive brain hypothesis

Q: The ecological hypothesis that seeks to explain the evolution of large brains in monkeys and apes considers which of the following to be the driving selection pressure favoring large brains?a. Folivory b. Frugivory c. Extractive foragingd. Learning

Q: Large brains may have initially evolved in monkeys and apes because they a. are more folivorous than their ancestors. b. have greater dexterity in their hands than their ancestors. c. are more likely to live in variable environments than their ancestors. d. have larger social groups than their ancestors.

Q: A link between social complexity and cognitive ability is predicted using a. a standardized measurement of cognition. b. absolute forebrain size. c. absolute neocortex size. d. a standardized measure of group size.

Q: The behavior of the great apes a. fits the social intelligence hypothesis very well. b. includes tool use and foraging on foods that are difficult to process. c. requires living in large groups. d. is more socially complex than monkeys.

Q: The executive brain ratio is closely linked toa. home range size. b. nocturnal activity patterns. c. forms of tool use.d. the amount of fruit in the diet.

Q: The neocortex ratio in primates is positively correlated witha. tool use. b. activity pattern. c. the extent of leaves in the diet.d. group size.

Q: The neocortex ratio a. includes the entire hindbrain. b. is the neocortex volume compared to brain volume. c. is the comparison of brain to body size. d. is the comparison of neocortex size to body size.

Q: The area of the brain that is most closely associated with problem solving and behavioral flexibility is thea. neocortex. b. executive brain. c. brain stem.d. hippocampus.

Q: One model of the evolution of intelligence proposes that the primate brain was selected to facilitate behavioral flexibility. This model relates toa. social challenges. b. foraging challenges. c. mating challenges.d. ranging challenges.

Q: Which of the following statements about social hypotheses for the evolution of intelligence in primates is NOT true? a. In larger groups, competition for food, mates, grooming partners, and other valuable resources selects for intelligence. b. In many primates, formation of social bonds used in coalitions, exchange networks, and access to resources selects for intelligence. c. The stresses of keeping track of social relationships in large groups select for intelligence in monkeys that live in large groups. d. The great apes are the most intelligent, have the largest brains, and live in the largest and most complex social groups.

Q: Ecological hypotheses about the evolution of intelligence include the ability to a. allocate investment to many offspring. b. use complex behavior to acquire or access hard-to-find or extracted food. c. enter into reciprocal relationships with conspecifics. d. understand how dominance influences access to food.

Q: Which of the following factors is hypothesized to contribute to the intelligence of primates? a. Teaching behaviors to others b. Provisioning c. Competitive pressures produced by sociality d. Manually manipulating food

Q: Interpret the following inequality as it pertains to parent"offspring conflict. Apply Hamilton's rule, from the current infant's perspective, assuming a gene expressed by the current infant increases maternal investment by a small amount. 1.0 x (increase in fitness of current fetus) 0.5 x (decrease in fitness of future offspring)

Q: Explain the phenomenon of genetic chimeras and how it relates to kin selection in cooperatively breeding marmoset groups.

Q: What evidence exists for reciprocal altruism in primates? Why would reciprocal altruism be common for primates but not for other animals?

Q: Conflict and aggression are a large part of group life for many primate species, which would seem disruptive to social bonds. What, then, keeps social groups cohesive?

Q: What is the evidence for maternal and paternal kin recognition? Illustrate your answer with examples.

Q: Construct a hypothetical example to illustrate how a gene causing altruism in an individual could increase in frequency through kin selection.

Q: What is Hamilton's rule? What are the two fundamental predictions of Hamilton's rule? Devise a primate scenario in which these two predictions of Hamilton's rule would be satisfied.

Q: What is group selection? Why do evolutionary biologists believe that individual selection will be more powerful than group selection when the two are in conflict?

Q: What is altruism? Why was it a puzzle for evolutionary biology before Hamilton?

Q: Compare altruism and mutualism in terms of the fitness effects on actors and recipients.

Q: Reconciliatory contact between opponents immediately following an aggressive encounter can reduce rates of self-scratching, an indicator of stress. If no reconciliation is attempted, then we can assume that a. rates of self-scratching drop back to baseline, regardless of stress level. b. rates of self-scratching remain above baseline, indicating high stress levels. c. only one opponent experiences high stress levels. d. the opponent will have high rates of aggression between them in the future.

Q: In recent studies of chimpanzees, researchers found that a. possessors of food were less likely to share their food with individuals who had recently groomed them. b. grooming is not reciprocal. c. grooming is sometimes a precursor for food sharing. d. grooming is exchanged for mating opportunities.

Q: In a study done with vervets, researchers found that a. genetic relatedness is necessary for contingent reciprocity to occur. b. they responded to recruitment calls from other monkeys after receiving grooming bouts from them. c. contingent reciprocity can evolve as confederates react appropriately to the presence and absence of reciprocity. d. agemates were more likely to be reciprocal.

Q: Evidence for reciprocal altruism a. is absent among primates because they cannot recognize kin. b. is absent among primates because they do not have long-term memories. c. exists among primates because they often live in stable social groups. d. exists among primates because of their longevity.

Q: Reciprocal altruism requires a. many interactions between kin. b. the ability to count. c. that there are no slackers or cheaters. d. sufficient memory to keep track of altruistic and nonaltruistic acts.

Q: In most promiscuously mating primate species that live in multimale, multifemale groups, mothers share 50% of their genes with their offspring. Different offspring of the same female are likely to share what percentage of their genes with each other?a. 0% b. 25% c. 50%d. 100%

Q: Even primate "friends" sometimes come into conflict. Their aggressive interactions may not have a detrimental effect on social cohesion if there isa. kin selection. b. altruism. c. grooming.d. reconciliation.

Q: Matrilines are an example ofa. altruism. b. kin recognition. c. grooming relationships.d. dominance relationships.

Q: Of the following, which is the most certain way to identify kin in primates?a. Phenotypic matching b. Age/cohort c. Proximity/contextd. Reconciliation

Q: Monkey A lives in a group with full siblings. Monkey B lives in a group with half siblings. Monkey C lives in a group with cousins. And monkey D lives in a group with its grandparents. For which monkey in which group is altruistic behavior most likely to occur?a. A b. B c. Cd. D

Q: Which of the following is predicted to occur after conflict results in violence as a way to mend relationships?a. Huddling b. Reconciliation c. Coalition formationd. Altruism

Q: Which of the following is true regarding parent"offspring conflict? a. Weaning is an example of parent"offspring conflict, and this transition reflects a fundamental symmetry in the genetic interests of mothers and offspring. b. A mother is equally related to each of her offspring; in contrast, an offspring is at most 25% related to its siblings but is 100% related to itself. c. A mother is motivated to wean her current infant so she can begin investment in her next infant, but the infant will resist its mother's attempts at weaning because it is not in its genetic best interest. d. Parent"offspring conflict only occurs in primates because reproductive costs are higher than for other mammals.

Q: Parent"offspring conflict occurs a. because parents and offspring share all of their genes. b. because individuals are more closely related to self than to siblings. c. only when siblings are not full siblings. d. only during weaning.

Q: The cooperative breeding system of primates such as marmosets and tamarins can be explained by a. chimerism, which increases fraternal twins' inclusive fitness when they help raise one another's offspring. b. helpers who care for the offspring of the breeding pair, although the helpers are usually not related to them. c. the fact that mothers sometimes allow their daughters to breed. d. mutualism between the nonbreeding helpers.

Q: Studies of red howler monkeys have shown that coalitions of a. fathers and daughters form enduring bonds that are the basis for social groups. b. related males are more likely to experience rank reversals. c. unrelated males last four times as long as coalitions of unrelated males. d. fathers and their maturing sons are necessary to repel incursions into their group by alien males.

Q: Which of the following statements do studies of macaques, vervets, and baboons support? a. Maternal rank is not a good predictor of a daughter's rank. b. Matrilineages rank above or below all members of other matrilineages. c. The stability of female dominance relationships is not a result of kin-based alliances. d. Females inherit patrilineal rank.

Q: Which of the following describes maternal rank and matrilineages in macaque, vervet, and baboon groups? a. Maternal rank is transferred to offspring, particularly daughters. b. Maternal kin occupy dissimilar ranks in the dominance hierarchy. c. Ranking within matrilineages is usually laterally transferred. d. Female dominance relationships are unstable over time.

Q: Which of the following is usually more common among kin than among nonkin in primate groups?a. Aggression b. Foraging c. Alarm callingd. Coalition formation

Q: The apparent stability in female dominance relationships in female-bonded primates may be due toa. abundant food supply. b. kin selection. c. sexual selection.d. habitat seasonality.

Q: Kin selection combined with females remaining in their natal group, in many primate species, has led to a. mutualistic behavior. b. asymmetrical behavior. c. the transmission of rank laterally from sister to sister. d. the transmission of rank from mothers to offspring.

Q: Baboon females a. have strong affinities for both maternal and paternal half sisters. b. are not able to distinguish maternal and paternal half sisters from unrelated females. c. prefer maternal half sisters over paternal half sisters. d. prefer paternal half sisters over maternal half sisters.

Q: When monkeys recognize paternal kin, they may rely ona. gender. b. genotype. c. age similarity.d. phenotype.

Q: Studies of kin recognition by female rhesus monkeys suggest that a. females had weak affinities for their maternal half sisters. b. facial resemblance could be a cue females use to distinguish paternal half sisters. c. females preferred agemates to maternal and paternal half sisters. d. females preferred maternal half sisters to unrelated agemates.

Q: Monkeys and apes recognize their kin through a. genotype mapping. b. patterns of male and female associations. c. contact with their mothers. d. age estimation of adult males in the group.

Q: Recent studies on kin recognition have found that age may provide a good proxy measure of paternal kinship in a. monogamous species. b. species where one male dominates mating activity in a group. c. groups with polygynous mating strategies. d. polyandrous groups.

Q: Phenotypic matching a. is context dependent. b. is common among apes but not monkeys. c. is the ability to recognize kin by a feature such as their smell. d. favors maternal kin over paternal kin.

Q: Primate altruism includesa. grooming conspecifics. b. sibling rivalry.c. autogrooming.d. sharing home ranges.

Q: Which of the following is predicted by Hamilton's rule? a. No altruism should evolve when r< 0.5. b. Altruism evolves only when r> 0.0. c. Altruism evolves only when r< 0.0. d. No altruism should evolve when r> 0.5.

Q: If the coefficient of relatedness between two individuals is 0.5, then a. altruism can evolve if c> 2b. b. altruism can evolve if c< 2b. c. altruism cannot evolve via kin selection. d. altruism will sometimes evolve regardless of the values of cand b.

Q: If the coefficient of relatedness between two individuals is zero (r= 0), then a. altruism can evolve if c> b. b. altruism can evolve if c< b. c. altruism cannot evolve via kin selection. d. altruism will sometimes evolve regardless of the values of cand b.

Q: Imagine a caregiver who helps raise a conspecific's offspring. Such caregiving reduces her fitness by 10% and increases the fitness of the recipient by 25%. According to Hamilton's rule, in which of the following scenarios could this behavior evolve?a. Groups of full siblings b. Groups of half siblings c. Both types of groupsd. Neither type of group

Q: Imagine a caregiver who helps raise a conspecific's offspring. Such caregiving reduces her fitness by 50% and increases the fitness of the conspecific by 50%. According to Hamilton's rule, in which of the following scenarios could this behavior evolve?a. Groups of full siblings b. Groups of half siblings c. Both types of groupsd. Neither type of group

Q: Imagine that an alarm caller sacrifices its life to save other conspecifics. According to Hamilton's rule, how many full siblings would it have to save for the behavior to be favored?a. at least 1. b. at least 2. c. at least 3.d. Hamilton's rule cannot be satisfied.

Q: The coefficient of relatedness (r) between mother and son isa. 0.25. b. 0.5. c. 0.75.d. 1.00.

Q: The coefficient of relatedness (r) between full siblings isa. 0.25. b. 0.5. c. 0.75.d. 1.00.

Q: The coefficient of relatedness (r) is a measure of a. each individual's fitness benefits. b. the probability that two individuals acquire the same allele through descent from a common ancestor. c. the probability that two randomly chosen individuals share an allele. d. sibling relatedness.

Q: Hamilton's rule states that a. altruism evolves only among nonkin. b. selfish genes swamp altruistic genes. c. altruistic behavior is favored if the cost to the actor is less than the benefit to the recipient, devalued by the degree of relatedness. d. altruistic behavior is favored if the benefits to the actor are greater than the costs to the recipients, devalued by their degree of relatedness.

Q: Kin selection predicts a. that group selection is more likely in families. b. that altruism is more likely among relatives. c. that altruism should occur only in higher animals. d. that only 50% of related individuals are altruistic.

Q: Altruistic behavior is more likely a. among kin than among nonkin. b. among nonkin than among kin. c. among kin than among nonkin, but only when kin and nonkin have the opportunity to interact. d. among nonkin than among kin, but only when nonkin interact with each other more than kin do.

Q: The key to the evolution of altruism is that a. recipients have to be more likely to carry the altruistic allele than nonrecipients. b. actors have to be more likely to carry the altruistic allele than nonactors. c. recipients have to be unrelated to the actors. d. nonrecipients have to be more likely to carry the altruistic allele than recipients.

Q: When group selection and individual selection are opposed, a. group selection prevails if groups are large and there is little migration. b. individual selection prevails. c. group selection usually prevails because the conditions for individual selection are too stringent. d. group selection never prevails.

Q: Although alarm calling benefits the whole group, it cannot be explained by group selection because a. callers make themselves conspicuous to the predators, but calling costs little in terms of individual fitness. b. calling reduces the risk of mortality for everyone who hears the call, changing the frequency of callers and noncallers in the population, because everyone benefits. c. noncallers benefit from the alarm call and will have higher fitness than the callers, so selection will suppress alarm calling. d. callers and noncallers have the same relative fitness.

Q: Group selection a. is likely to occur in primates because they live in well-established social groups. b. is likely to occur in primates because certain behaviors benefit the whole group. c. is unlikely to occur in primates because certain behaviors may benefit the group to the detriment of the actor. d. is unlikely to occur in primates because it is a theoretically unsound principle.

Q: Coalitions among male baboons a. allow middle-ranking, cooperative males a chance to gain access to receptive females. b. are an example of mutualistic behavior as all males get equal mating opportunities. c. do not allow lower-ranking males to outcompete higher-ranking males. d. can predict male grooming relationships.

Q: Mutualistic behaviors a. are common in nature when animals work together. b. are rare because "slacking" is often profitable for individuals, not groups. c. involve only kin and never unrelated individuals. d. are profitable for the actor but not the recipient.

Q: Two unrelated male baboons work together to guard a female in estrus to keep away a more dominant male. This is an example ofa. mutualism. b. altruism. c. reciprocal altruism.d. kin selection.

Q: Which of the following is true of altruism? a. Altruism is a strategy favored by sexual selection. b. Altruism can evolve only if the benefit to the group is very high compared with the cost to the actor. c. Altruism cannot simultaneously increase the fitness of all members of the group. d. Altruism cannot evolve unless there is no cost to the actor.

Q: Altruism at first was a puzzle to evolutionary biologists because a. it should be more common in nature because it increases the fitness of recipients. b. it should be more common in nature because it increases the fitness of species. c. it should not be common in nature because it decreases the fitness of actors. d. it should not be common in nature because it decreases the fitness of species.

Q: By definition, altruistic behaviors a. incur a cost to the recipient. b. incur a cost to the actor. c. result in a benefit to the actor. d. are beneficial to the recipient and the actor.

Q: Explain why it is important that we study and understand reproductive strategies of animals, and primates specifically.

Q: What is the evidence demonstrating the importance of socializing for female primates?

Q: Discuss the better documented counterstrategies to infanticide evolved by female primates, and give specific primate examples from the reading.

Q: How does the threat of infanticide influence male"female relationships in baboons? Include in your answer a discussion of mating effort and parenting effort.