Chapter 10 Part Two Flashcards
Monogamous rock-haunting ringtail possum is an example of and provides support for the ________________ hypothesis
mate limitation hypothesis (low female density and broad dispersion)
What type of factors influence the mating behaviors of the rock-haunting ringtail possum?
ecological factors
Mating with more than on male per female occurs in (none, few, many, or all) of the 14 major taxonomic groups explored in one study and in _____% of the populations examined
1) all
2) 89%
Galapagos hawk mating system = ____________
ranges along a continuum from monogamy to extreme polyandry (associated with scarcity of suitable territories; males then outnumber the limited # of territorial, breeding females)
males then form cooperative defense teams to hold sites; females generate a male harem of up to 8 partners all of whom have an equal chance of fertilizing the females eggs making the mean fitness of each individual, as part of a team, greater than any single individual alone
Wattled jacana mating systems
bird species of territorial females that fight for and defend preferred territories and give each male his own clutch of eggs to care for
75% of the clutches laid by polyandrous females are of mixed paternity so males tend to care not just for their own offspring but for others as well (males are monogamous)
Red phalarope mating systems
shorebird; females are larger and more brightly colored than males
females fights for males and the male then provides parental care for the clutch he receives regardless of the paternity of that clutch (males are monogamous)
red necked phalarope
care for broods of their own; males prefer his original sexual partner 9/10 times reducing the risk that the eggs he will care for were fertilized by another male
spotted sandpiper
sex-role reversed species; females lead courtship, are larger, and are more combative
females arrive first to breeding grounds and fight between each other for territories; second male she mates with has a reduced chance of having fertilized all of the eggs if his mate had stored sperm from the first male; only a few females reach greater reproductive success than the males (atypical results for most animals - greater female reproductive variance)
spotted sandpipers (can/cannot) reach greater reproductive success by laying more eggs in each clutch having utilized rich food resources.
CANNOT: stuck at 4 egg only clutches, any more has negative consequences
Must produce more clutches then to reach greater reproductive success as they cannot produce more eggs within a single clutch
Because males care for the clutches while females defend territories, to have greater reproductive success means the need to acquire another mate to then care for the additional clutch(es)
For female spotted sandpipers, female fitness is limited by _____________ more so than production of __________, which is rare among animals.
1) access to mates
2) gametes
Male spotted sandpipers are forced into monogamy because of what ecological factors:
adult sex ratio - limited opportunity for polygyny for males, females compete for access to mates
nesting areas - super abundant mayfly (food) provides ample resources to care for young and support multiple clutches
young are precocial - move, feed, and thermoregulate themselves
all these factors mean that females enjoy the benefit of knowing their initial clutch would have optimal chances of survival should they move on to produce an additional clutch
What hypothesis is this: females mate polyandrously to produce offspring of higher genetic quality or viability
good genes hypothesis
The grey foam nest treefrog is an example that provides support for what hypothesis explaining the genetic benefits of polyandry in females
a. good genes hypothesis
b. genetic compatibility hypothesis
c. genetic diversity hypothesis
d. inbreeding avoidance hypothesis
a. good genes hypothesis
female clutches that have been fertilized by at least ten males (which occurs for 90% of females) had a greater chance of surviving to metamorphosis than the tadpoles from females having only had a single mate
yellow toothed cavy (guinea pig)
example providing support for the good genes hypothesis; females who copulate with more than one male have a reduction in the rates of stillbirths and losses of babies before weaning
dark-eyed juncos
greater reproductive success in subsequent offspring; greater supply of nutrients given to the larger sized eggs produced by females of this species for extra-pair mates leads to higher quality sons and fecund females from those extra pair matings
superb-fairy wren mating provides support for the ____________ hypothesis
good-genes hypothesis (they have the highest rate of extra pair paternity of any other avian species)
“The sexy son” idea refers to what, and what specific species did the book refer to for this?
sons inherit the attractiveness of their fathers as the result of extra-pair mating leading them to be more successful reproductively (females also inherit the same tastes for these attractive males); dark-eyed juncos, superb fairy-wrens, and field crickets
European starlings “sexy son”
research indicated that sons inherit behavioral qualities from their polygynous fathers and their subsequent optimal behavioral qualities are not the result of maternal effects from hormones deposited in the eggs (same given to eggs fathered by monogamous vs. polygynous mates)
Older males in songbirds species have (better or worse) reproductive success compared to younger males
better (support for the good genes hypothesis - they’ve demonstrated a strong ability to survive)
cuckholding mates, evident in some species including the blue tit, provides support for what hypothesis regarding mating systems?
good genes hypothesis (females uninfected with malaria but paired with mates infected will seek more extra pair copulations)
Genetic compatibility hypothesis
females mate polyandrously to increase the odds of receiving genetically complementary sperm
When gametes with especially compatible genes unite, they result in highly viable progeny
female pseudoscorpions prefer (new or previous) partners providing support for what hypothesis?
1) new
2) genetic compatibility hypothesis
If presented with same mate 90 minutes later will reject his spermatophore 85% of the time
Genetic diversity hypothesis
females mate polyandrously to increase the heterozygosity (genetic diversity) of either individual offspring or of the group of offspring produced in a single bout
Support for the genetic diversity hypothesis
Individual level:heterozygous offspring less likely than homozygous offspring to have potential defects as a result of recessive alleles.
Group level: greater diversity in the population as a whole may allow survival of the species if exposed to disease outbreak or better survival odds in a range of environmental conditions
Avian examples providing support for the genetic diversity hypothesis
superb starlings - those seeking extra pair copulations had mate pairs with partners less heterozygous than themselves and extra pair copulations resulted in more heterozygous offspring
bluethroat - extra pair offspring more heterozygous than mate pair offspring (and those more heterozygous offspring also enjoyed greater immune functioning)
Mammalian examples providing support for the genetic diversity hypothesis
madrills - brightly colored faces preferred (sexually selected honest signal); females mate with genetically compatible males with genes most dissimilar to their own (MHC - major histocompatibility complex)
MHC variation plays a role in what
mate choice decisions; greater variation = greater heterozygous and dissimilar genetic makeup for mating
Seychelles warbler females will seek extra pair matings if their mate pair has (high/low) MHC diversity
low
- There is a positive association between MHC diversity and juvenile survival offering support for the idea that MHC diversity and the extra pair copulations that are influenced by that diversity produce genetic benefits in the form of a more diverse immune system
Eusocial insects and support for the genetic diversity hypothesis
genus Apis (honey bee): highly polyandrous females (accepting sperm from 10-63 males depending on species)
Evidence provides support for __________ being the ancestral mating system of bees with __________ being a more recent derived characteristic.
1) monogamy
2) polyandry
Most queen bees need only mate once to obtain enough sperm for a lifetime of reproduction
Benefits of polyandry among bee species
genetic diversity; midler forms of foulbrood disease compared to bees with monogamous queen; greater colony-level disease resistance; less variation within a species on the level of immune responses; genetically diverse workforce (better equipped for survival)
