polygyandry vs promiscuity
Polygyandry: Both males and females mate with many partners, often with some level of cooperation or shared parental care.
Promiscuity: Both males and females mate with many partners, with no pair bonding or parental cooperation.
queen honey bees are ___ while the drones are ___.
polyandrous; monogamous
socio-ecological framework of mating systems
under typical asymmetries, ___ are the limited sex while ___ are the limiting sex.
if resources are monopolizable, ____ or ____ systems will emerge depending on which is the ___ sex.
If not, ___ or ____ will evolve as the resources drives living together.
If resources are unnecessary to breed, then _____ is more likely.
male; female
polygynous; polyandrous; limiting
monogamy; polygynandry
promiscuity
there are 4 hypotheses of how monogamous systems evolve. what are they?
mate limitation hypothesis - potential mates dont form group, roam widely, too costly to locate and defend many
mating guarding hypothesis - restrict mating behavior of partner
mate assistance hypothesis - resources critical to reproduction and both parents necessary to raise young
infanticide hypothesis - high rate of infanticide, partner can help defend young
multiple mating has fitness cost, and an example is increased ____ count showing higher infection rate.
white blood cell
describe female mate guarding in burying beetle.
after female lays eggs, male will climb a perch and emits pheromones to call other females. sensing these pheromones, female partner will run and push male off his perch, ending the signal
in european starlings, _____ improve success of offspring. having 2 parents at a nest offset high ___ and ___ of raising young. thus the monogamy.
parental care; cost; workload
in prairie voles, males guard and pair with females. they defend offspring from mainly ____.
infanticide
in white-handed gibbons, there is much ___ risk of infanticide in _____ pairs that ____.
lower; monogamous; polyandrous groups
in rock-haunting ringtail possum, pattern of ___ distribution favors a ____ mate guarding system.
female; monogamous
in red phalaropes (shorebirds), how can male monogamy to a polyandrous female function if the male is raising offspring of other males?
it is the cost the male has to take to have any offspring at all, thus male is taking a small net benefit in a compromised situation.
why are spotted sand pipers polyandrous?
- OSR is male-biased
- nest around immense mayfly hatches (food)
- single parent can do as well as pair
there are 4 hypotheses supporting indirect benefits of polyandry. what are they?
- good genes hypothesis - produce higher quality offspring
- genetic compatibility hypothesis - increase odds of receiving geentically complimentary sperm (eg. pseudoscorpions)
- genetic diversity hypothesis - increase genetic diversity
- inbreeding avoidance hypothesis - avoid inbreeding
sons of sexually successful males are more successful than sons of less sexually successful males.
what is this hypothesis
sexy son hypothesis
in blue tits and bluethroats, offsping of ____ had stronger immune response.
EPC
what is MHC?
major histocompatibility complex
MHC genes code for proteins in our immune system and play a role in binding foreign antigens
compared to ___ hives, polyandrous bee hives has stronger ______ system, produced more ____, and some (__%) survived the winter, unlike ___ hives that do not survive winter.
monogamous; immune; honeycomb; 25%; monogamous
in purple-crowned fairy wrens, females of ____ pairs are more likely to engage in EPC (__%) while in typical pairs only ___%.
this shows that polyandrous mating functions to lower the costs of _____.
incestuous; 46; 3
incest
state the 3 hypotheses that support direct benefits of polyandry.
- additional resources hypothesis
gain more resources
eg. red-winged black bird, bee, butterflies - additional care hypothesis
gain more caregivers
eg. dunnocks - infanticide reduction hypothesis
create greater uncertainty about paternity of offspring to reduce infanticide
eg. hanuman langurs - males that have mated with females unlikely to commit infanticide
what are the 4 hypotheses supporting functions of polygynous systems?
- female defense hypothesis
female forms groups to better access resources/reduce predation risks, and males will follow and guard them - resource defense polygyny hypothesis
when resources are clumped, males defend territories against multiple females - lek polygyny hypothesis
females widespread, don’t form groups, males wait for them at leks where the resources are - scramble competition polygyny hypothesis
females widespread, don’t form groups, males find females
female defense hypothesis
resource defense polygyny hypothesis
lek polygyny hypothesis
scramble competition polygyny hypothesis
match the above to the below:
- resources are evenly distributed
- resource distribution is clumped
- resources are distributed heterogeneously/unevenly
- resources are evenly distributed
- female defense hypothesis - resource distribution is clumped
- resource defense polygyny hypothesis - resources are distributed heterogeneously/unevenly
- lek polygyny hypothesis
- scramble competition polygyny hypothesis
female gorillas group together ro defend from predators. males form ______ to compete for and control access to these groups.
harems aka dominant male groups
the below demonstrates the _________ hypothesis in __________ systems.
amphipods construct ______made of pebbles and shells, and ____ them to their _____ to transport them around.
males capture females by gluing its house to its own, so male can ____ female against rival males.
this behaviour results in _________ of up to ___ female houses per male.
female defense; polygymous
houses; glue; bodies
defend
apartment complexes; 3
male bats that can guard a female harem can sire as many as ___ offspring per year.
50
