Chapter 10 Part Two

Question 1

Monogamous rock-haunting ringtail possum is an example of and provides support for the ________________ hypothesis

Answer 1

mate limitation hypothesis (low female density and broad dispersion)

Question 2

What type of factors influence the mating behaviors of the rock-haunting ringtail possum?

Answer 2

ecological factors

Question 3

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

Answer 3

1) all

2) 89%

Question 4

Galapagos hawk mating system = ____________

Answer 4

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

Question 5

Wattled jacana mating systems

Answer 5

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)

Question 6

Red phalarope mating systems

Answer 6

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)

Question 7

red necked phalarope

Answer 7

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

Question 8

spotted sandpiper

Answer 8

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)

Question 9

spotted sandpipers (can/cannot) reach greater reproductive success by laying more eggs in each clutch having utilized rich food resources.

Answer 9

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)

Question 10

For female spotted sandpipers, female fitness is limited by _____________ more so than production of __________, which is rare among animals.

Answer 10

1) access to mates

2) gametes

Question 11

Male spotted sandpipers are forced into monogamy because of what ecological factors:

Answer 11

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

Question 12

What hypothesis is this: females mate polyandrously to produce offspring of higher genetic quality or viability

Answer 12

good genes hypothesis

Question 13

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

Answer 13

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

Question 14

yellow toothed cavy (guinea pig)

Answer 14

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

Question 15

dark-eyed juncos

Answer 15

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

Question 16

superb-fairy wren mating provides support for the ____________ hypothesis

Answer 16

good-genes hypothesis (they have the highest rate of extra pair paternity of any other avian species)

Question 17

“The sexy son” idea refers to what, and what specific species did the book refer to for this?

Answer 17

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

Question 18

European starlings “sexy son”

Answer 18

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)

Question 19

Older males in songbirds species have (better or worse) reproductive success compared to younger males

Answer 19

better (support for the good genes hypothesis - they’ve demonstrated a strong ability to survive)

Question 20

cuckholding mates, evident in some species including the blue tit, provides support for what hypothesis regarding mating systems?

Answer 20

good genes hypothesis (females uninfected with malaria but paired with mates infected will seek more extra pair copulations)

Question 21

Genetic compatibility hypothesis

Answer 21

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

Question 22

female pseudoscorpions prefer (new or previous) partners providing support for what hypothesis?

Answer 22

1) new
2) genetic compatibility hypothesis
If presented with same mate 90 minutes later will reject his spermatophore 85% of the time

Question 23

Genetic diversity hypothesis

Answer 23

females mate polyandrously to increase the heterozygosity (genetic diversity) of either individual offspring or of the group of offspring produced in a single bout

Question 24

Support for the genetic diversity hypothesis

Answer 24

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

Question 25

Avian examples providing support for the genetic diversity hypothesis

Answer 25

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)

Question 26

Mammalian examples providing support for the genetic diversity hypothesis

Answer 26

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)

Question 27

MHC variation plays a role in what

Answer 27

mate choice decisions; greater variation = greater heterozygous and dissimilar genetic makeup for mating

Question 28

Seychelles warbler females will seek extra pair matings if their mate pair has (high/low) MHC diversity

Answer 28

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

Question 29

Eusocial insects and support for the genetic diversity hypothesis

Answer 29

genus Apis (honey bee): highly polyandrous females (accepting sperm from 10-63 males depending on species)

Question 30

Evidence provides support for __________ being the ancestral mating system of bees with __________ being a more recent derived characteristic.

Answer 30

1) monogamy
2) polyandry

Most queen bees need only mate once to obtain enough sperm for a lifetime of reproduction

Question 31

Benefits of polyandry among bee species

Answer 31

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)