Parental Investment (4a) Flashcards
Parental investment/Parental care attributes? (2)
• Gamete related.
• Benefit of current offspring.
What do we mean by benefit of current offspring?
We mean that the benefit of raising this offspring MUST OUTWEIGH producing more offspring. AKA quality over quantity.
Benefits of adaptive value of parental care?(2)
• Improved survival of offspring.
• Improved quality of offspring.
Costs of adaptive value of parental care? (2)
• Reduced future survival of parent.
• Reduced mating opportunities for parent.
In parental care, what do offspring always do?
Offspring always try & get more from parents.
It’s optimal for the parent to do what?
To invest a certain amount of energy into the 1st offspring (wean), then invest in producing a 2nd offspring when cost of raising no.1 > benefits of raising no.2.
It’s optimal for offspring to do what? (2)
• Demand investment from mother until mother’s fitness starts to decline.
• Decrease inclusive fitness
- because ½ of offspring genes are shared with mother.
Inclusive fitness?
= a measure of an individual’s total genetic contribution to subsequent generations.
Inclusive fitness/fitness types? (2)
• Direct fitness.
• Indirect fitness.
Direct fitness?
= personal reproduction/an individual’s fitness.
Indirect fitness?
= additional reproduction by relatives (made possible by an individual’s actions).
Kin selection?
= care for others/other siblings to facilitate offspring growth.
Who does parental care?
Generally provided by females.
Why is parental care generally provided by females?
Anisogamy.
When might paternal behavior evolve?
When costs of parenting for males is less than that for females.
Why does Infanticide happen?
It is because the males don’t think that they are the father of the offspring produced.
If males are more confident that an offspring is theirs, what happens?
They take care of the offspring.
Egs of animal populations that practice Infanticide? (2)
• Wild dogs.
• Lions.
How do colony-based species recognize their offspring?
By specific calls known to offspring.
Eg of offspring recognition? Explain
Bats.
• where they have a specific call frequency that the offspring know.
Kin selection basically?
= where animal risks itself to save relatives.
Eg of kin selection?
Meerkats.
Confidence of paternity hypothesis?
= hypothesis that states that one should expect the parent with the highest certainty to be parental care-giver.
2 types of fertilization under Confidence of paternity hypothesis?
- Internal fertilization.
* External fertilization.
Describe the 2 types of fertilization.
● Internal fertilization.
= maternal care.
● External fertilization.
= paternal care.
Eg of external fertilization?
Frog fertilization.
In Parental-Offspring Conflict: # Offspring, Why don’t parents have lots of offspring?
It depends on the trade-offs of:
• offspring # & quality (more offspring, low quality).
• offspring # & parental reproductive success (reproductive success is independent of offspring #, as long as the offspring can produce their own offspring, i.e., will grandchildren be produced?).
What does sibling rivalry solely depend on?
Food supply.
2 influences of sibling rivalry?
• Asynchronous laying.
• Incubation of young.
How do the 2 influences affect sibling rivalry?
● Asynchronous laying.
= less sibling rivalry.
● Incubation of young.
= more sibling rivalry.
Why don’t parents step in to save the attacked young?
It depends. If:
● Chicks all same size.
= more fighting, poor survival.
● Chicks different sizes.
= less fighting, better survival.
Care allocation by sex, who gets better parental care?/Who is invested in more?
Male offspring.
Why are male offspring given better care & quality of food?
Sexy sons hypothesis.
Eg of care allocation by sex? Explain.
Songlarks.
- where male offsprings grow faster because mothers give better quality food to sons.
Parental investment/Parental care?
= any parental trait that increases the fitness of the offspring & is likely to have originated and been currently maintained for this function.
What is preferred in parental care?
That the benefits outweigh the costs of caring for offspring.
Explain the Parental investment graph observed in Rhesus monkeys?
It explains/shows that offspring are always trying to get more from their parents.
How are Meerkats an example of Kin selection?
Meerkat that warns other meerkats of incoming predator (meerkat on the lookout) risks its life to save its relatives.
Egs of offspring recognition? (4)
• Fry.
• Cliff swallows.
• Bats.
• Ring-billed gulls.
Results of parents not treating offspring equally? (3)
• Sibling rivalry.
• Siblicide.
• Parental favouritism.
Things that the eldest chicks are allowed to do by the parents? (2)
• Attack & kill younger siblings.
• Drive younger ones from the nest.
Egs of organisms that are Obligate brood reducers? (2)
• African black eagles.
• Giant pandas.
Egs of organisms that are facultative brood reducers? (2)
• Cattle egret.
• Blue-footed boobies.
Obligate brood reducers attributes? (2)
• Insurance against failure (polyovulating).
• Eldest is allowed to attack & kill younger siblings.
Why do giant pandas abandon the 2nd cub?
It’s because it’s a burden to provide milk of for more than one cub is too much.
Why is there an unequal distribution of food to offspring?
It’s because it’s more beneficial to focus on the offspring that is already strong than the offspring that is weak.
Trade offs of unequal parental care? (2)
• Offspring number vs Quantity.
• Offspring number vs Parental future reproductive success.
Why do parents allow eldest to kill other siblings?
Because of resource limitations.
Facultative brood reducers attributes? (4)
• Environmental capacity (policy of parental optimisms).
• Eldest is allowed to drive younger ones from the nest.
• Parent feeds stronger ones & starve weaker offspring.
• Solely depends on food supply.
Why does the parent feed stronger offspring & starve the weaker offspring?
It’s because of limited food supply.
Blue-footed boobies features? (2)
• Conditional siblicide.
• Policy of parental optimisms.
What do we mean when we say conditional siblicide?
We mean that siblings are killed if their weight is less than 80% normal.
How do parents evaluate the reproductive value of offspring?
By checking for a red colour as this indicates the presence of carotenoid pigments & therefore a stronger immune system and increased survival.
Explain the differential allocation of sex? (2)
● Increased density population, less resources, females get more preferential treatment as resources aren’t enough to ensure males get big enough.
● Decreased density population, more resources, males get more preferential treatment as resources are enough to ensure males get big enough.
Egs of male only parental care? (3)
• Seahorses.
• Mallee fowls.
• Sticklebacks.
Why male only parental care? (2)
• Costs are less in males than in females.
• Confidence of paternity hypothesis.
Eg of where there is both parents caring for offspring?
St. Peter’s fish.
St. Peter’s fish spawning options/instances? (3)
• Biparental care.
• Male only care.
• Female only care.
Thing to note about St. Peter’s fish?
Mouthbrood.
Results of mouthbrooding? (2)
• Weight loss due to reduced feeding.
• Cost of brood care is increased in females than males.
Confidence of paternity hypothesis?
= states that the sex providing parental care is more likely to take care of the offspring.
How do parents recognize their young? (2)
• Chemicals.
• Sound frequency of sound calls.
Thing to note in sound calls in colonies?
More colonies, Higher chance of recognizing colonies.
What is the consequence of SS?
Parental care.
Parental care forms among others from start to end? (4)
• Gamete provision.
• Egg attendance.
• Egg brooding.
• Offspring maturation.
Result of more parental investment?
Produces more reproductive & fit offspring that can survive.
