Inbreeding Flashcards
1
Q
implications of inbreeding (2)
A
- all of us carry deleterious recessive alleles and close relatives likely carry some of the same bad alleles
- mating with close relatives gives these alleles a good chance to pair up into homozygotes
2
Q
inbreeding consequences
A
- inbreeding depression
3
Q
inbreeding depression
A
- increased homozygosity of the entire genome, may result in reduced fitness
4
Q
what causes inbreeding depression (2)
A
- expression of deleterious recessive alleles
- loss of heterosis
5
Q
- when does inbreeding increase
A
- with closeness of inbreeding
6
Q
examples of inbreeding depression (3)
A
- corn inbreeding resulted in lower smaller corns due to loss of heterosis
- more birds eggs fail as inbreeding in creases
- mortality rate of offspring is greater of first cousins than of unrelated parents
7
Q
inbreeding depression formula
A
inbreeding depression = 1 - (Winbred/Woutbred)
8
Q
what are Winbred and Woutbred measures of
A
- measures of traits that correlate with fitness
9
Q
inbreeding avoidance mechanisms (4)
A
- mate choice (kin recognition)
- dispersal
- differences in maturation times between brothers and sisters
- morphological adaptations
10
Q
morphological adaptations to avoid inbreeding (4)
A
- plants with separate sexes
- male/female structures in separate flowers
- heterostyly
- pollen self incompatibility
11
Q
permanently inbred species (3)
A
- fig wasps
- naked mole-rats
- social spiders
12
Q
how are social spiders inbred (4)
A
- in an established colony, a females with egg-sacs will leave to form a new colony
- offspring mature and mate
- colony size increases
- offspring mature and mate again and colony size increases to become an established colony
13
Q
when is inbreeding depression expected to be a problem (2)
A
- when an outbred species switches to inbreeding
- social spiders are though to have originated from outbred subsocial species
14
Q
outbred spiders (4)
A
- single female with egg-sac
- spiderlings grow
- spiders disperse as subadults
- spiders mate
15
Q
when should inbreeding be tolerated (2)
A
- when costs of avoiding inbreeding exceed costs of inbreeding depression
- graph costs of avoiding depression against inbreeding depression
16
Q
cost of avoiding inbreeding (3)
A
- due to dispersal as subadults
- due to solitary living as adults
- costs: finding mates, predation, etc
17
Q
long term effects of inbreeding (2)
A
- purging of recessive deleterious alleles
- high homozygosity and low variability
