PCB 3043 Chapter 10

Why might selfish behaviors be less favored when animals interact with closely related family members? -Close relatives are more likely to retaliate severely in response to selfish behaviors than unrelated individuals. -Closely related individuals share genes and can indirectly increase each others fitness through successful reproduction. -An individual that acts selfishly toward close relatives increases the fitness of the relatives at the expense of its own fitness. -Committing a selfish act against close relatives often causes an individual to produce fewer offspring of its own.

-Closely related individuals share genes and can indirectly increase each others fitness through successful reproduction.

A population of territorial mammals experiences an increase in population density. Why might individuals in the population give up defending their territories? -Less aggressive individuals are significantly less likely to be noticed by predators. -Sharing resources make individuals more attractive to the many potential mates. -Individuals do not have to travel as far to find food as competition rises. -Defending territories is too costly against the greater number of conspecifics.

-Defending territories is too costly against the greater number of conspecifics.

What is the difference between direct and indirect fitness? -Direct fitness is a measure of the number of offspring an individual produces. Indirect fitness measures the fitness an individual gains by helping care for another's offspring. -Direct fitness quantifies natural selection on phenotype, whereas indirect fitness measures natural selection on genotype. -Direct fitness measures the health of an individual, whereas indirect fitness measures the health of the population. -Direct fitness quantifies he advantageous mutations an individual passes to its offspring. Indirect fitness quantifies the advantageous mutations in the individual's extended family.

-Direct fitness is a measure of the number of offspring an individual produces. Indirect fitness measures the fitness an individual gains by helping care for another's offspring.

The coefficient of relatedness is the probability that two individuals have inherited the same copies of a gene from a recent common ancestor. The coefficient of relatedness ranges from 0 to 1, which indicates that the compared pair is either not at all related or genetically identical, respectively. Determine the coefficient of relatedness between each pair of specified family members. Enter your answers in decimal form and do not round your answers. Full sister and brother in a haplodiploid system:

0.25

The coefficient of relatedness is the probability that two individuals have inherited the same copies of a gene from a recent common ancestor. The coefficient of relatedness ranges from 0 to 1, which indicates that the compared pair is either not at all related or genetically identical, respectively. Determine the coefficient of relatedness between each pair of specified family members. Enter your answers in decimal form and do not round your answers. Full sister and brother in a diploid system:

0.5

Classify each situation according to whether it would favor the evolution of cooperation or altruism: A young adult scrub jay cannot find a breeding territory of its own so it remains with its parents and helps raise their next brood of chicks.

Altruism

Classify each situation according to whether it would favor the evolution of cooperation or altruism: The fertile sisters of sterile honeybee workers need feeding and tending if they are to grow and reproduce.

Altruism

Classify each situation according to whether it would favor the evolution of cooperation or altruism: Meerkats have more time to find food and tend to offspring if all the meerkats take turns guarding the colony of several families.

Cooperation

Classify each situation according to whether it would favor the evolution of cooperation or altruism: Unrelated wolves that form a pack are more likely to catch enough prey than they would be if they each hunted alone.

Cooperation

Classify the benefits to individual birds as a result of living in a large or small flock: Easier to find infrequent or hidden food sources.

Large flock

Classify the benefits to individual birds as a result of living in a large or small flock: Increased access to genetically diverse mates.

Large flock

Classify the benefits to individual birds as a result of living in a large or small flock: Lower probability of being attacked by a predator.

Large flock

Classify the benefits to individual birds as a result of living in a large or small flock: Less competition for food.

Small flock

Male pied kingfishers rarely produce young in their first year as adults. Some young males, called primary helpers, aid their parents in raising a brood of chicks. Primary helpers increase their parents' fitness by 1.8 chicks. Because a parent is commonly replaced by a stepparent, the coefficient of relatedness, r, between the primary helpers and the chicks equals 0.32. Secondary helpers help and unrelated set of parents raise a brood of chicks and increase these parents' fitness by 1.3 chicks. The coefficient of relatedness between the secondary helpers and the chicks they help raise is 0. Delayers are males that don't help raise any chicks in their first adult year. During their second adult year, primary helpers, secondary helpers, and delayers have, on average, 2.5 chicks, but the survival rates, Psm, vary between these males. Primary helpers have a Psm of 0.32, secondary helpers a Psm of 0.67, and delayers a Psm of 0.29. Calculate the inclusive fitness of the primary helpers. -0.98 -0.40 -0.58 -1.83

-0.98

Calculate the inclusive fitness of an elephant that has two calves and has helped raise two of her cousins. The coefficients of relatedness, r, for a parent and offspring is 0.5 and between cousins is 0.25. Assume that the probability of survival for the elephants is 100%. -1.0 -1.5 -4.0 -2.5

-1.5

Which of the following is a characteristic of a eusocial species? -Non-overlapping generations of parents and offspring living together in the same group. -One adult and numerous juveniles living within a small group. -A reproductive dominance hierarchy made up of one or a few dominant individuals and the presence of sterile (non-reproductive) individuals. -Pairs of individuals building nest structures and caring for offspring together.

-A reproductive dominance hierarchy made up of one or a few dominant individuals and the presence of sterile (non-reproductive) individuals.

What does inclusive fitness measure? -How many offspring an individual produces. -The survival rate of an individual. -An individual's direct and indirect fitness. -The genetic profile of an individual.

-An individual's direct and indirect fitness.

Suppose a goat farmer wants to use artificial selection to breed goats for increased milk production in the most cost-effective way possible. What strategies would be most effective for the goat farmer to use? -Breed offspring from the herd with the highest milk production. -Have goats live in social herds. -Have goats live and breed in different places. -Breed the females with highest milk production.

-Breed offspring from the herd with the highest milk production. -Have goats live in social herds.

How does direct fitness differ from indirect fitness? -Indirect fitness only occurs in eusocial species. -Direct fitness is better for eusocial species because each individual has a very high coefficient of relatedness. -Direct fitness involves an individual participating in the reproduction and care of its own offspring; indirect fitness involves an individual caring for the offspring of related individuals. -Indirect fitness is the survival and reproduction of an individual, and direct fitness is the survival of an individual to reproductive age.

-Direct fitness involves an individual participating in the reproduction and care of its own offspring; indirect fitness involves an individual caring for the offspring of related individuals.

In a haplodiploid mating system, how can the coefficient of relatedness between two sisters be 0.75 (75%)? -Male and female bees are both diploid. The males contribute 100% of their genes to their offspring, and females contribute 50%. Therefore, each female offspring shares 75% of her genes with her sister siblings on average. -If a queen mates with a single drone, then all the resulting females have all of the same genetic contribution from the male, since males are haploid and contribute 100% of their genes. -Females can reproduce asexually, meaning they produce clones, and those clones share on average 75% of the genes of their sisters. -Females are haploid, and they pass on 100% of their genes, whereas males are diploid and pass on 50% of their genes, meaning that the coefficient of relatedness is 0.75.

-If a queen mates with a single drone, then all the resulting females have all of the same genetic contribution from the male, since males are haploid and contribute 100% of their genes.

Select the statements of evidence that a haplodiploid sex-determination system is not required for the evolution of eusociality. -Prairie dog colonies are dominated by an alpha female and alpha male who produce diploid male and female offspring. -Naked mole rat colonies are dominated by a queen and several kings who produce diploid male and female offspring. -Bee colonies are dominated by a queen and several fertile males who produce diploid male and female offspring. -Termite colonies are dominated by a queen and king who produce diploid male and female offspring.

-Naked mole rat colonies are dominated by a queen and several kings who produce diploid male and female offspring. -Termite colonies are dominated by a queen and king who produce diploid male and female offspring.

Male pied kingfishers rarely produce young in their first year as adults. Some young males, called primary helpers, aid their parents in raising a brood of chicks. Primary helpers increase their parents' fitness by 1.8 chicks. Because a parent is commonly replaced by a stepparent, the coefficient of relatedness, r, between the primary helpers and the chicks equals 0.32. Secondary helpers help and unrelated set of parents raise a brood of chicks and increase these parents' fitness by 1.3 chicks. The coefficient of relatedness between the secondary helpers and the chicks they help raise is 0. Delayers are males that don't help raise any chicks in their first adult year. During their second adult year, primary helpers, secondary helpers, and delayers have, on average, 2.5 chicks, but the survival rates, Psm, vary between these males. Primary helpers have a Psm of 0.32, secondary helpers a Psm of 0.67, and delayers a Psm of 0.29. Select the statement that is true about inclusive fitness in these kingfishers. -Primary helpers have both higher indirect and direct fitness. -Secondary helpers have the lowest rates of inclusive fitness because both their direct fitness and indirect fitness is low. -Only primary helpers increase their inclusive fitness by increasing indirect fitness. -Secondary helpers and delayers gain a fitness advantage through indirect fitness.

-Only primary helpers increase their inclusive fitness by increasing indirect fitness.

Male pied kingfishers rarely produce young in their first year as adults. Some young males, called primary helpers, aid their parents in raising a brood of chicks. Secondary helpers help an unrelated set of parents raise a brood of chicks. Delayers are males that do not help raise any chicks in their first adult year. Male role/Indirect fitness/Direct fitness Primary helper/0.32/0.40 Secondary helper/0.00/0.84 Delayer/0.00/0.29 Given the data found In the table, which reproductive strategy leads to the highest inclusive fitness and which to the lowest. -Delayer, secondary helper. -Primary helper, secondary helper. -Primary helper, delayer. -Secondary helper, delayer.

-Secondary helper, delayer.

A breeding pair of birds receives help raising their young from an unrelated male bird. How might providing this assistance improve the fitness of the unrelated male bird? -Because he does not ever produce offspring of his own, the helper bird has a longer and healthier life. -The cooperative relationship helps the unrelated male survive until he can find a mate and produce offspring of his own. -Rearing unrelated offspring delays sexual maturity in the helper bird so he has fewer offspring over the course of his life. -In exchange for help at the nest, the breeding pair offers the helper male some of their offspring to rear as his own.

-The cooperative relationship helps the unrelated male survive until he can find a mate and produce offspring of his own.

Under what conditions does natural selection favor individuals that live in groups, such as herds or flocks? -When the chance of finding a high-quality mate increases in a group. -When working as a group makes it easier for individuals to obtain enough food. -When the risk of predation is reduced for individuals in a group. -When being in. a group means each individual spends more time on vigilance.

-When the chance of finding a high-quality mate increases in a group. -When working as a group makes it easier for individuals to obtain enough food. -When the risk of predation is reduced for individuals in a group.

Termites are a diploid eusocial species in which a colony's queen and king produce both sons and daughters through sexual reproduction. What evolutionary reasons may explain why workers forgo reproduction unless the king or queen dies? -Workers that leave the home colony are unlikely to establish a new colony. -Workers increase their indirect fitness by contributing to the survival of their siblings. -Workers are more closely related to their siblings than they are to their own offspring. -Workers have a higher direct fitness than kings and queens.

-Workers that leave the home colony are unlikely to establish a new colony. -Workers increase their indirect fitness by contributing to the survival of their siblings.

The coefficient of relatedness is the probability that two individuals have inherited the same copies of a gene from a recent common ancestor. The coefficient of relatedness ranges from 0 to 1, which indicates that the compared pair is either not at all related or genetically identical, respectively. Determine the coefficient of relatedness between each pair of specified family members. Enter your answers in decimal form and do not round your answers. Mother and son in a diploid system:

0.5

Classify the benefits to individual birds as a result of living in a large or small flock: More opportunity to feed.

Large flock

Classify the benefits to individual birds as a result of living in a large or small flock: Less conspicuous to predators.

Small flock

Classify the benefits to individual birds as a result of living in a large or small flock: Lower transmission rates of diseases.

Small flock