IB 329 EXAM 3 REVIEW QUESTIONS
Costs of parental care, types of investment - Answers - Costs: time, energy, vulnerable
to predation
Types of investment: protection from predation, protection from elements,
provisioning/feeding
Influence of operational sex ratio & differential investment into gametes on parental care
- Answers - Operational sex ratio influence on parental care:
female biased in polygynous species
biased towards males --> parental care is at a timely cost. Variance in reproductive
success is higher, don't have 100% confidence offspring is theirs
Differential gamete investment influence on parental care:
Females initially invest more than males, confident offspring is theirs --> they should
provide majority of parental care
Tradeoffs between current vs. future reproduction - Answers - Time, energy, risks spent
by parent on current offspring (parental investment) can influence possibility of having
future offspring.
Young v old parents
Bi-parental care and male biased parental care (why?) - Answers - common in birds,
males provide more parental care than females, males take the burden of care knowing
offspring are theirs
Why: caring for the right offspring provides fitness benefit through increased young
survival
Offspring recognition: mechanisms & tradeoffs - Answers - Take care of the right
offspring
Requires recognition system
Sibling conflict: parental & offspring perspectives - Answers - Sibling agression and
siblicide
Parental: only one offspring is essential to pass on genes (masked booby - first
surviving offspring always kills the second)
Offspring: competition for resources
Parent-offspring conflict - Answers - Some actions that increase fitness of offspring may
reduce fitness of parents.
Conflict higher with younger parents - still have high rep. potential.
Conflict higher as offspring age - benefit/cost ratio of taking care of young decreases
, Parental favoritism: ultimate explanation
Asynchrony in hatching? - Answers - - Occurs when resources are variable and adults
have more young than they can raise (bet hedging)
Ex: Differential investment into eggs, Young fed preferentially - ex: barn swallows -
differential feeding based on color signal
Ultimate explanation: parents max fitness by putting all resources into one offspring
Asynchrony in hatching increases parental care efficiency, increases or dec. favoratism
Genetic basis for mating system/parental care - Answers - The vole/vasopressin
example: single gene (vasopressin) responsible for parental care and pair bonding
Praire voles - monogamous, parental care - vasopressin receptor expressed at higher
levels
Meadow voles - polygynous, no male parental care
What are helpers at the nest? Direct and indirect benefits of helping? - Answers -
Juveniles delaying their dispersal to help second nesting effort.
Direct: learning about parental care, inherit territory & resources
Indirect: passing on genes through helping relatives
Nest helpers - who helps? How does it relate to: Overlapping generations? Dispersal? -
Answers - Usually females juveniles.
Primary helpers = offspring of parents, get indirect benefit, expend most energy
Secondary helpers = non offspring, get direct benefit
- Dispersal is delayed, reduces cost associated w/ dispersal
-Promotes overlapping generations, key to the evolution of social groups
What is inclusive fitness? - Answers - Total fitness gained by helping:
Direct fitness(own rep.) + Indirect fitness (relative's rep.)
We share more genes with relatives than the pop., by helping them we pass on those
shared genes!
Reasons for helping (proximate versus ultimate) - Answers - Proximate:
learning/expeience, becoming a better parent
Ultimate: increase fitness
-Indirect genetic benefits (help relatives)
-Territory limitation
-Learning/experience
What is reproductive skew (RS)
-Factors influencing degree of RS
-Incentives to allow RS - Answers - The distribution of reproduction across members of
a group, high = only few ppl. rep., low = everyone rep. equally
- Factors:
Costs of parental care, types of investment - Answers - Costs: time, energy, vulnerable
to predation
Types of investment: protection from predation, protection from elements,
provisioning/feeding
Influence of operational sex ratio & differential investment into gametes on parental care
- Answers - Operational sex ratio influence on parental care:
female biased in polygynous species
biased towards males --> parental care is at a timely cost. Variance in reproductive
success is higher, don't have 100% confidence offspring is theirs
Differential gamete investment influence on parental care:
Females initially invest more than males, confident offspring is theirs --> they should
provide majority of parental care
Tradeoffs between current vs. future reproduction - Answers - Time, energy, risks spent
by parent on current offspring (parental investment) can influence possibility of having
future offspring.
Young v old parents
Bi-parental care and male biased parental care (why?) - Answers - common in birds,
males provide more parental care than females, males take the burden of care knowing
offspring are theirs
Why: caring for the right offspring provides fitness benefit through increased young
survival
Offspring recognition: mechanisms & tradeoffs - Answers - Take care of the right
offspring
Requires recognition system
Sibling conflict: parental & offspring perspectives - Answers - Sibling agression and
siblicide
Parental: only one offspring is essential to pass on genes (masked booby - first
surviving offspring always kills the second)
Offspring: competition for resources
Parent-offspring conflict - Answers - Some actions that increase fitness of offspring may
reduce fitness of parents.
Conflict higher with younger parents - still have high rep. potential.
Conflict higher as offspring age - benefit/cost ratio of taking care of young decreases
, Parental favoritism: ultimate explanation
Asynchrony in hatching? - Answers - - Occurs when resources are variable and adults
have more young than they can raise (bet hedging)
Ex: Differential investment into eggs, Young fed preferentially - ex: barn swallows -
differential feeding based on color signal
Ultimate explanation: parents max fitness by putting all resources into one offspring
Asynchrony in hatching increases parental care efficiency, increases or dec. favoratism
Genetic basis for mating system/parental care - Answers - The vole/vasopressin
example: single gene (vasopressin) responsible for parental care and pair bonding
Praire voles - monogamous, parental care - vasopressin receptor expressed at higher
levels
Meadow voles - polygynous, no male parental care
What are helpers at the nest? Direct and indirect benefits of helping? - Answers -
Juveniles delaying their dispersal to help second nesting effort.
Direct: learning about parental care, inherit territory & resources
Indirect: passing on genes through helping relatives
Nest helpers - who helps? How does it relate to: Overlapping generations? Dispersal? -
Answers - Usually females juveniles.
Primary helpers = offspring of parents, get indirect benefit, expend most energy
Secondary helpers = non offspring, get direct benefit
- Dispersal is delayed, reduces cost associated w/ dispersal
-Promotes overlapping generations, key to the evolution of social groups
What is inclusive fitness? - Answers - Total fitness gained by helping:
Direct fitness(own rep.) + Indirect fitness (relative's rep.)
We share more genes with relatives than the pop., by helping them we pass on those
shared genes!
Reasons for helping (proximate versus ultimate) - Answers - Proximate:
learning/expeience, becoming a better parent
Ultimate: increase fitness
-Indirect genetic benefits (help relatives)
-Territory limitation
-Learning/experience
What is reproductive skew (RS)
-Factors influencing degree of RS
-Incentives to allow RS - Answers - The distribution of reproduction across members of
a group, high = only few ppl. rep., low = everyone rep. equally
- Factors:
