chapter 14 Flashcards
activities of adult that ENHAnCE SURVIRORSHIP of offspring is called
parental care
invilved with growth, reproduction, and survivorshiipi; result of natural selection this is called
life history traits
Hypothesis that assume natural selection favors behaviors/ traits that maximize individual lifetime reproduction success this is called
life history theory
Natural selection favors evolution of behaviors that maximize an individual’s lifetime reproductive success
-energy (effort) is limited
This is called?
Life history trade-offs
Reproductive effort reduces growth and survivorship effort
-tradeoffs
this is called?
Energy (effort) is limited
Life history trait species A (fly) species B Species C (humans)
Fecundity ________ ________ _____________
Survivorship _________ ________ ______________
Parental care _________ ________ ______________
Life history trait species A (fly) species B Species C (humans)
Fecundity High Intermediate Low
Survivorship Low Intermediate High
Parental care Low Intermediate High
Many small offspring, high growth rate, little parental care this is called
Ex) mice
R-selected species
Fewer, larger offspring, slow growth rate, lots of parental care this is called
Ex) elephant
K- selected species
Can life history theory explain variation in fish?
Larger body= larger maturation, larger eggs, fewer reproductive events per year, and higher level of parental care
-small species= opposite trend
(therefore patterns reflect BASIC LIFE HISTORY TRADE OFFS)
Do humans show history trade-offs?
Analyzed female British aristocracy over 1100 years
-NEGATIVE CORRELATION between lifespan and offspring
-Positive correlation between lifespan and age of first reproduction
-both patterns consistent with life history theory trade-offs
variation in parental care in humans
-species vary in parental care
-only females (_______________)
-Only males (_______________)
-both species (_________________)
1) maternal care
2) paternal care
3) bi-parental care
Females typically ____________________ than males
provide more parental care
each sex has different benefits/cost of providing care
sexual conflict
-females KNOW offspring are theirs
-Males less certain of OFFSPRING PATERNITY; have a higher cost of providing care (care for unrelated individuals)
-evolution of REDUCED CARE by males
this is called
Paternity Uncertainty
Why do males vary the level of care within a clutch of offspring in boobies?
certainty of paternity affects males level of care
-males will provide low care when certainty of paternity is low
The evolution of male-only care
-Mammals and birds= _______________-
-Fish, amphibians, and reptiles= _____________
1) female-biased parental care
2) Male-biased
Mammals and birds=
INTERNAL FERTILIZATION/ DETERMINATE growth (reach adult size)
Fishes, and amphibians (and some reptiles)=
EXTERNAL FERTILIZATION/ INDETERMINATE growth (never stop growing
increase certainty of paternity
-larger females produce more eggs, parental care costly to females
-limits growth and FUTURE FECUNDITY
-For fish, higher costs for females vs lower costs for MALE ONLY CARE
external fertilization
(The evolution of male only care)
-Paternity certainty affected by __________________________
mode of fertilization
(The evolution of male-only care)
-_________________ growth affects fecundity
Indeterminate
(The evolution of male-only care)
Male-only care can evolve in species with ____________ fertilization and ___________ reproductive events
-external
-multiple
(the evolution of male-only care)
-________________: multiple reproductive events throughout lifetime
Iteroparity
(the evolution of male-only care)
_______________: reproduction occurs only once
Semelparity
What affects the level of male parental care in bluegill sunfish?
-Males should reduce care as their certainty of paternity declines to avoid caring for unrelated offspring
-males that observe sneakers near their nest during spawning should provide less care to eggs compared to males that do not see sneakers near their nest during this period
(parental care affected by paternity certainty)
Why do water bugs have male only care despite having internal fertilization and sperm storage by females?
Male water bugs have a HIGH DEGREE OF CERTAINTY of percentage despite having INTERNAL fertilization
What is the benefit of parental care
enhance survivorship of young
what is the cost of parental care?
reductions in both current and future reproduction
Parents and offspring under different SELECTED PRESSURES:
-Parents- maximize REPRODUCTIVE SUCCESS
-Offspring-Maximize energy /protection received from parents to survive to reproductive age
this is called
Parent-offspring conflict theory
Increasing offspring SURVIVAL at cost of parents ability to invest in other offspring this is called
parental investment
Optimal level of parental investment is ALWAYS HIGHER FOR OFFSPRING THEN FOR PARENT this is called
parent-offspring conflict theory
(predation risk and parental care in songbirds)
Common costs of parental care is PREDATION RISK
-________________________: parents should maximize their LIFETIME reproductive fitness; offspring should maximize the energy and protection in order to survive to reproductive age
Parent-offspring conflict theory
(predation risk and parental care in songbirds)
results:
-Pre-stimulus and control periods- ______________ in food delivery rates
-Predator stimulus treatment- __________ food delivery rate
1) no difference
2) reduce
(predation risk and parental care in songbirds)
-Adults __________ level of parental care in response to a heightened risk of ________________
-supports parent-offspring conflict theory
1) Modify
2) mortality
If egg-guarding parental care increases offspring success, why don’t all males attend eggs at a high level in frogs?
Males with SMALL CLUTCHES may be searching for additional mating opportunities
Within a species, why is there much variation in parental care such as egg guarding in treehoppers?
1) egg guarding will increase egg survival (current reproduction)
2) Increased egg guarding will decrease future reproduction
Birds incubate eggs to maintain HIGH TEMPERATURES for proper development. How costly is it?
Individuals with large clutches will pay high incubation costs and experience lower reproductive fitness in the future compared to those with small clutches
Differential offspring mortality often within single clutch
-Adaptive for parent= reduces cost of CURRENT REPRODUCTION enhances survivorship and FUTURE REPRODUCTION
this is called
Brood reduction
Chicks hatch on different days this is called
Hatching asynchrony
Does hatch asynchrony affect offspring mortality?
Hatching asynchrony facilitates brood reduction by creating offspring of DIFFERENT SIZE/ COMPETITIVE ABILITY
Some marine mammals give birth in consecutive years, but pups not weaned for two years. Lactation costs are high for female with two pups, the younger pup rarely survives this is called
Brood reduction
Why fo females give birth in consecutive years in fur seals?
Brood reduction (pup death) is function of FOOD AVAILABILITY. Parents can raise pups in consecutive years when food availability is high, but cannot be PREDICTED IN ADVANCE
__________________ is common in birds of prey (endangered eagles)
- __________________ increases survivorship of second offspring
1) brood reduction
2) Food supplementation
Brood parasitism reduces the cost of parental care and can result in a ___________________________
Co-evolutionary arms race
Females lays egg in the nest of CONSPECIFIC FEMALES
-reduces cost of parental care
this is called
Brood parasitism
Brood parasites can lay all (__________) or some eggs (_______________) in the nest of another female
1) pure parasite
2) nesting parasites
What reproductive strategy leads to the highest fitness (pure parasite, nesting parasite (mixed strategy), or nonparasites?
Nesting parasites had highest reproductive success
(brood parasitism ENHANCES FITNESS in part by reducing cost of PARENTAL CARE
-Females lays an egg in nest of another species this is called
Interspecific brood parasitism
Only lays eggs in nest of another species this is called
ex) brown-headed cowbirds
Obligate brood parasite
Why do some host species accept most parasite eggs while other species reject most parasite eggs?
1) evolutionary lag hypothesis
2) Bill size hypothesis
(evolutionary history with brown-headed cowbirds and bill length explain VARIATION IN EGG REJECTION)
Species with SHORT HISTORY OF COEXISTENCE with parasites will be acceptors; those with long history will have evolved to be egg REJECTORS this is called
Evolutionary lag hypothesis
Only species with LARGE BILLS can lift egg out of nest to reject it this is called
Bill size hypothesis
Radical changes in behavior during breeding season
-Early: concentrate on ____________________ mates
-Later: concentrate on _____________________
-_________ causes parental care to occur
1) finding and attracting
2) providing care to offspring
3) prolactin
_____________ : Hormone that influences PARENTAL CARE
-levels in VERTEBRATES VARY over reproductive season
Prolactin
Does prolactin affect parental care in rats?
Prolactin strongly affects parental care behavior
(females with prolactin exhibited higher levels vs. controls and females not primed exhibited little care)
In birds what causes prolactin levels to increase during egg laying?
1) sight of eggs stimulates prolactin production
2) Tactile stimulation (brood patch contact with eggs) stimulates prolactin production
What hormone lowers parental care in earwigs?
JH (Juvenile hormones)
