ANTH, Ch. 6

false

According to Darwin's theory of natural selection, only those behaviors or modifications that increase longevity are favored and retained in subsequent generations. true or false?

true

Competition in the quantity of sperm leading to differences in testes size is most likely to occur in social groups in which females often mate with multiple males during estrus, such as in multimale, multifemale groups. true or false?

males transfer in the company of other transferring males; males choose to disperse to a group with resident males that they are already familiar with; males investigate neighboring groups before leaving their natal group

Dispersal is often a dangerous and stressful time for males. Which of the following are tactics that males often use because they reduce the cost of leaving their natal group? -Males can choose to stay permanently on their own. -Males transfer in the company of other transferring males. -Males choose to disperse to a group with resident males that they are already familiar with. -Males can attempt to join more than one group at a time in order to determine which one will accept him. -Males investigate neighboring groups before leaving their natal group.

true

Hrdy's hypothesis that infanticide is an evolved reproductive strategy has been subject to criticism. Sommer believes that the criticism is the result of "naturalistic fallacy." true or false?

true

Humans and other primate species have many elements of reproductive physiology in common. true or false?

access to food, reproductive success, predation rates

In some situations, female primates develop dominance hierarchies within social groups. Identify the areas affected by an individual female's rank. -access to food -reproductive success -predation rates -sociality

neither males nor females actively care for the young

In the animal world, how do most species care for their offspring? -Both males and females actively care for their young. -Mostly males actively care for the young. -Mostly females actively care for the young. -Neither males nor females actively care for the young.

true

Infanticide is sometimes a substantial source of mortality in a primate group. true or false?

false

Intersexual selection plays a more significant role in primates than intrasexual selection. true or false?

they can use their resources to acquire other mates; caring for young does not increase their fitness

Male primates typically do not care for their offspring. Which of the following are accurate explanations of why they do not care for their offspring? -Females do not allow males to care for the young. -They can use their resources to acquire other mates. -Caring for young does not increase their fitness. -Males lack knowledge of how to care for offspring. -Males lack sufficient energy to care for offspring.

true

Males groom females more often than females groom males as a function of mate guarding. true or false?

false

Multimale, multifemale groups are generally associated with high levels of male parental investment. true or false?

the fitness of offspring raised by one parent is high; acquiring additional mates is relatively easy

Parenting strategies vary greatly in the animal kingdom. One strategy is unequal parental investment, in which males contribute very little, if anything, to rearing the offspring. Identify the situations in which unequal parental investment will be favored. -The fitness of offspring raised by one parent is high. -Acquiring additional mates is relatively easy. -Females give birth to multiple infants at once. -Females are widely separated in an environment.

true

Primate females are predisposed to invest in their offspring to a greater degree than primate males because females lactate. true or false?

male reproductive success

Sarah Hrdy suggests that the occurrence of infanticide among langurs is an evolved strategy. What might infanticide enhance in primates that practice it? -the ability of females to care for young, since resources are shared among fewer infants -female reproductive success -male reproductive success -the genetic fitness of offspring

intrasexual selection

Sexual dimorphism arises from _______________ ______________.

true

Sexual dimorphism is most pronounced in species with high levels of competition between males, such as in one-male, multifemale groups. true or false?

females who lack male support will be greatly stressed when the group is overtaken by a strange male, as there are no males to protect them from the new leader

Stress levels of female baboons are depicted in the graph below, plotting cortisol (a stress hormone) levels in relation to various events in the social group as well as to whether or not the female has a close male associate. What can be concluded from this graph? -Having a male friend makes no difference to female stress levels. -Females who lack male support will be greatly stressed when the group is overtaken by a strange male, as there are no males to protect them from the new leader. -Females are more stressed when their group is taken over by a relative than by an outsider. -Females with male friends will be the most stressed during a group takeover because their alliance makes them targets.

higher rank leads to higher chances of reproductive success

Studies across a wide range of primate species demonstrate which of the following regarding the rank of the female? -The higher one's rank, the more one will be displaced from prime feeding sites. -Higher rank leads to higher chances of reproductive success. -Higher rank increases the chances of being rejected by a mate. -Higher rank lowers one's chances of reproducing successfully.

females usually produce twins; males play an active role in childcare

Tamarins and marmosets are rare among primates in their reproductive strategies. Identify the characteristics of tamarin and marmoset reproductive strategies. -females usually produce twins -males play an active role in childcare -They are mainly solitary. -Low- and high-ranking females breed equally.

false

The male in one-male, multifemale groups has assured, exclusive access to the females. true or false?

foraging efficiency

The term ___________ ____________ refers to the quantity of nutrients obtained per unit of time.

true

Various primate behaviors, such as chimpanzees using hammers to crack open nuts, would not evolve by natural selection unless they somehow enhanced reproduction. true or false?

reproduction

What is the central act of all living things?

increases genetic fitness

What kind of benefit must a particular behavior provide for it to be considered an evolutionary advantage for a primate? -provides animal with longer life -increases genetic fitness -improves animal's learning process -allows animal to have better social interactions

longevity, rank, age, social bonds

Which features drive variation in female reproductive performance? -longevity -rank -age -social bonds -access to mates

females try to protect the offspring; females try to confuse males about paternity

Which of the following are potential counterstrategies to prevent infanticide in primates? -Females try to protect the offspring. -Females try to confuse males about paternity. -Females hide their young from infanticidal males. -Females use weapons to fight off males.

male-female relationships are affected by the threat of infanticide; infanticide is an evolved reproductive strategy in males

Which of the following are true regarding infanticide? -Male-female relationships are affected by the threat of infanticide. -Infanticide is an evolved reproductive strategy in males. -Infanticide is never a major source of mortality for infants. -Females rarely attempt to stop infanticide from occurring.

subtly resist a juvenile's attempt to nurse

Which of the following is a typical method a primate mother uses to encourage independence in her offspring? -Subtly resist a juvenile's attempt to nurse. -Ignore them altogether. -Turn them over to another primate mother. -Give them a threatening gesture.

nursing offspring for an extended period of time

Which of the following is an aspect of mating that humans have in common with other primates? -nursing offspring for an extended period of time -male parental investment -females can only become pregnant during a short period of time once per year -pair bonding is the most common mating system

her ability to obtain nutrient-rich resources

Which of the following is the most important factor in determining a female primate's reproductive success? -her ability to attract males -her ability to influence males -her ability to obtain nutrient-rich resources -her ability to get males to protect her

male gorillas mate guarding their female partners; baboon males threatening each other; male and female gibbon pairs vocalizing together

Which of the following primate activities are behaviors that evolved to enhance reproduction? -male gorillas mate guarding their female partners -baboon males threatening each other -male and female gibbon pairs vocalizing together -chimpanzees learning sign language to communicate with humans

intersexual selection does not play a significant role in primates; sexual selection results in male adaptations that enhance their ability to compete with other males for access to females; intrasexual selection favors traits that increase success in male-male competition

Which of the following statements accurately describe a feature of sexual selection in primates? -Intersexual selection does not play a significant role in primates. -Sexual selection results in male adaptations that enhance their ability to compete with other males for access to females. -Intrasexual selection favors traits that increase success in male-male competition. -Sexual selection is not as strong as ordinary selection.

females form friendships with one or two adult males; male friends can intervene on behalf of their female friend and protect the female's young

Which of the following statements regarding the threat of infanticide in baboons and its impact on male-female relationships are true? -Females form friendships with one or two adult males. -Females avoid all males in order to avoid the possibility of infanticide. -A friendship between a female with offspring and a male can increase the chances of infanticide. -Male friends can intervene on behalf of their female friend and protect the female's young.

INTERSEXUAL SELECTION: females choose mates; attractive traits that indicate quality; rare among primates INTRASEXUAL SELECTION: male-male competition; larger canines

Which of these features of sexual selection characterize intersexual selection and which characterize intrasexual selection? -females choose mates -attractive traits that indicate quality -rare among primates -male-male competition -larger canines

all of the above

Which of these features related to mating systems and reproductive behaviors are known to vary in primates? -courtship patterns -parental care -mate choice -all of the above

females fight over access to food resources

Why are dominance hierarchies among the females of a primate species formed? -Females fight over access to food resources. -It improves fitness and reproductive success for all of the females. -Females fight over access to males. -It helps distribute care for infants.