IB 329 EXAM 3 QUESTIONS WITH VERIFIED ANSWERS
parental care types of investment - Answers - -protection from predation
-protection from elements
-provisioning/feeding
parental care costs - Answers - -time
-energy
-vulnerable to predation
bigger gametes - Answers - increase zygote size and survival
more gametes - Answers - increase potential number of offspring
females initial investment - Answers - more than males
larger gamete size, internal development in some animals
do females have a greater incentive to make sure their initial investment is not wasted?
- Answers - if so, females should provide the majority of parental care
variance in reproductive success - Answers - -usually greater for males than females
(especially in polygynous species)
-times spent caring for offspring = less mating opportunities
-potential reproductive rate is greater for males than females
is cost of parental care greater for males or females? - Answers - males
EPCs - Answers - -parental care should be proportional to probability offspring are
yours
-females can be quite confident of maternity, males (when females mate multiply) are
less confident of paternity
how much investment should parents make on current offspring? - Answers - increased
investment = increased probability/increased fitness for parents
trade off between current and future reproduction? - Answers - time, energy, risks spent
by parent on current offspring (parental investment) can influence possibility of having
future offspring
life history traits - Answers - characteristics of an individual that influence survival and
reproduction
-age at maturity
-number of offspring produced
,-lifespan
-number of reproductive events
potential tradeoff - Answers - -more energy invested now, less energy available for
future reproductive efforts
-increased parental investment can affect survival of adults (potentially decreasing
fitness)
-therefore, each increment of parental care is subject to selection
operational sex ratio - Answers - -ratio of sexually receptive males to receptive females
-females limited by number of eggs, gestation, so ratio often male biased
bi-parental care - Answers - common (particularly in birds)
male biased parental care - Answers - -in some species, males provide more care than
females
-greater rhea, seahorses, African cichlids
-solenosteira macrospira
-giant water bugs
solenosteira macrospira - Answers - -the male's shell is covered with numerous egg
cases
-after mating, females deposit egg cases on their mate's shell, and the males carry this
burden (which can exceed 50% of the male's wet mass) until the eggs hatch
giant water bugs (belostomatidae) - Answers - -large bugs, eggs also larger than typical
aquatic insect
-need to exchange gases (CO2 out, O2 in) which is easier out of water
-males carry eggs glued to back
-males moisten eggs laid out of water
is male biased parental care really an exception to the rule? - Answers - if males help
rear young, fitness increases through increased young survival
what is parental care driven by? - Answers - the distribution of resources, the
operational sex ratio, previous investments, ecological conditions
caring for the right offspring - Answers - -offspring recognition in colonial species
-mexican free-tailed bats
-cliff swallows can recognize own young, rough winged swallows cannot
caring for the wrong offpsring - Answers - -it is not worth making a mistake and not
caring for your own offspring (recognition systems are not perfect)
-communal care of offspring common in some species that live in groups
-dwarf mongoose
-brood parasites (cowbirds, cuckoos)
, brood parasites-cowbirds - Answers - -caring for the wrong offspring, the extreme
-bay-winged cowbird: colonial, builds own nests, egg dumping?
-screaming cowbird: lays eggs in nests of 1 species, the bay-winged cowbird
-shiny cowbird: lays eggs in nests of 176 species
sibling conflict - Answers - -sibling aggression and siblicide
-occurs when resources are variable or in short supply?
-offspring compete for resources (only share 50% of genes)
-masked booby: have two eggs, first hatched chick always kills second chick
-blue-footed booby: have two eggs, often raise two young
parent-offspring conflict - Answers - -selection may act on parents and offspring
differently
-some actions that increase fitness of offspring may reduce fitness of parents
-*conflict higher with younger parents* (still have high potential reproduction)
-*conflict increases as offspring age* (and benefit/cost ratio of taking care of young
decreases)
parental favoritism - Answers - -likely occurs when resources are available and adults
have more young than they can raise (bet hedging)
-females can invest in eggs differently (even choose sex in some species)
-young can be fed preferentially
-honest signals of quality in offspring?
-asynchrony in hatching (birth order) can promote or reduce sibling conflict and parental
favoritism
can parents control sex of offspring? - Answers - -haplo/diploid organisms (like ants,
bees and wasps)
fertilized egg = female; un-fertilized egg = male
-temperature dependent sex determination (TSD): many reptiles
genetics basis for mating system/parental care - Answers - -prairie voles: monogamous,
male parental care
-meadow voles: polygynous, no male parental care
-in male prairie voles, vasopressin and dopamine in the forebrain regulate affiliation
between mates (bond formation)
-vasopressin receptor is expressed at higher levels in prairie voles (monogamous
species) than in meadow voles (polygynous species)
-Lim and colleagues, used a viral vector to transfer the vasopressin receptor gene from
the prairie vole (monogamous species) into the meadow voles (polygynous species)
-with this change in a single gene, the polygynous species essentially became
monogamous and males exhibited parental care
mechanisms of parental favoritism - Answers - -differential feeding/care
-number of eggs/size of litter
parental care types of investment - Answers - -protection from predation
-protection from elements
-provisioning/feeding
parental care costs - Answers - -time
-energy
-vulnerable to predation
bigger gametes - Answers - increase zygote size and survival
more gametes - Answers - increase potential number of offspring
females initial investment - Answers - more than males
larger gamete size, internal development in some animals
do females have a greater incentive to make sure their initial investment is not wasted?
- Answers - if so, females should provide the majority of parental care
variance in reproductive success - Answers - -usually greater for males than females
(especially in polygynous species)
-times spent caring for offspring = less mating opportunities
-potential reproductive rate is greater for males than females
is cost of parental care greater for males or females? - Answers - males
EPCs - Answers - -parental care should be proportional to probability offspring are
yours
-females can be quite confident of maternity, males (when females mate multiply) are
less confident of paternity
how much investment should parents make on current offspring? - Answers - increased
investment = increased probability/increased fitness for parents
trade off between current and future reproduction? - Answers - time, energy, risks spent
by parent on current offspring (parental investment) can influence possibility of having
future offspring
life history traits - Answers - characteristics of an individual that influence survival and
reproduction
-age at maturity
-number of offspring produced
,-lifespan
-number of reproductive events
potential tradeoff - Answers - -more energy invested now, less energy available for
future reproductive efforts
-increased parental investment can affect survival of adults (potentially decreasing
fitness)
-therefore, each increment of parental care is subject to selection
operational sex ratio - Answers - -ratio of sexually receptive males to receptive females
-females limited by number of eggs, gestation, so ratio often male biased
bi-parental care - Answers - common (particularly in birds)
male biased parental care - Answers - -in some species, males provide more care than
females
-greater rhea, seahorses, African cichlids
-solenosteira macrospira
-giant water bugs
solenosteira macrospira - Answers - -the male's shell is covered with numerous egg
cases
-after mating, females deposit egg cases on their mate's shell, and the males carry this
burden (which can exceed 50% of the male's wet mass) until the eggs hatch
giant water bugs (belostomatidae) - Answers - -large bugs, eggs also larger than typical
aquatic insect
-need to exchange gases (CO2 out, O2 in) which is easier out of water
-males carry eggs glued to back
-males moisten eggs laid out of water
is male biased parental care really an exception to the rule? - Answers - if males help
rear young, fitness increases through increased young survival
what is parental care driven by? - Answers - the distribution of resources, the
operational sex ratio, previous investments, ecological conditions
caring for the right offspring - Answers - -offspring recognition in colonial species
-mexican free-tailed bats
-cliff swallows can recognize own young, rough winged swallows cannot
caring for the wrong offpsring - Answers - -it is not worth making a mistake and not
caring for your own offspring (recognition systems are not perfect)
-communal care of offspring common in some species that live in groups
-dwarf mongoose
-brood parasites (cowbirds, cuckoos)
, brood parasites-cowbirds - Answers - -caring for the wrong offspring, the extreme
-bay-winged cowbird: colonial, builds own nests, egg dumping?
-screaming cowbird: lays eggs in nests of 1 species, the bay-winged cowbird
-shiny cowbird: lays eggs in nests of 176 species
sibling conflict - Answers - -sibling aggression and siblicide
-occurs when resources are variable or in short supply?
-offspring compete for resources (only share 50% of genes)
-masked booby: have two eggs, first hatched chick always kills second chick
-blue-footed booby: have two eggs, often raise two young
parent-offspring conflict - Answers - -selection may act on parents and offspring
differently
-some actions that increase fitness of offspring may reduce fitness of parents
-*conflict higher with younger parents* (still have high potential reproduction)
-*conflict increases as offspring age* (and benefit/cost ratio of taking care of young
decreases)
parental favoritism - Answers - -likely occurs when resources are available and adults
have more young than they can raise (bet hedging)
-females can invest in eggs differently (even choose sex in some species)
-young can be fed preferentially
-honest signals of quality in offspring?
-asynchrony in hatching (birth order) can promote or reduce sibling conflict and parental
favoritism
can parents control sex of offspring? - Answers - -haplo/diploid organisms (like ants,
bees and wasps)
fertilized egg = female; un-fertilized egg = male
-temperature dependent sex determination (TSD): many reptiles
genetics basis for mating system/parental care - Answers - -prairie voles: monogamous,
male parental care
-meadow voles: polygynous, no male parental care
-in male prairie voles, vasopressin and dopamine in the forebrain regulate affiliation
between mates (bond formation)
-vasopressin receptor is expressed at higher levels in prairie voles (monogamous
species) than in meadow voles (polygynous species)
-Lim and colleagues, used a viral vector to transfer the vasopressin receptor gene from
the prairie vole (monogamous species) into the meadow voles (polygynous species)
-with this change in a single gene, the polygynous species essentially became
monogamous and males exhibited parental care
mechanisms of parental favoritism - Answers - -differential feeding/care
-number of eggs/size of litter
