Kinship and Kin recognition

Question 1

discriminative parental care

Answer 1

cognitive or physiological mechanisms will evolve for recognizing offspring, but only if there is risk of error.

breeding colonies of bats, after pup is born the mother hangs it from the cave roof and goes to forage. Moms recognize pup’s smells and sounds

Question 2

swallows discrimination

Answer 2

cliff swallows- discriminate parental care. young often leave nest and move around, so parents will recognize chick’s voices and face before care. the chicks themselves have more variety in their sounds

barn swallows- non discriminate parental care. rare to find another chick in their nest, they’re very dispersed. no parental recognition, will accept fosters.

Question 3

lambs discriminatory care

Answer 3

mother ewe will inspect her lamb at birth, learns its individual odour and rejects all other lambs so she’s not parasitized.

Question 4

what sort of discriminations would parents make?

Answer 4

1. phenotypic quality: can this offspring convert parental investment into parental fitness?
2. quantity and need: how much difference will this investment make?
3. identity: is this my offspring?

Question 5

human examples of discrimination

Answer 5

parentage matters, more resources given to genetic offspring
offspring quality matters some parents may abandon or kill offspring

Question 6

direct kin

Answer 6

offspring and grand offspring

Question 7

other kin

Answer 7

any other relatives who arent direct descendants.

Question 8

coefficient of relatedness

Answer 8

r.
% of genes that are shared by individuals of common descent.

Question 9

r for parent to offspring?

Answer 9

0.5

Question 10

r for grandparent - grandoffspring?

Answer 10

0.25

Question 11

r for first cousins?

Answer 11

0.125

Question 12

Hamilton’s Rule

Answer 12

if rB-c > 0, then altruism will occur
r=relatedness
B=benefit
c=costs

Question 13

alarm calls

Answer 13

vocalizations that alert other animals to danger. callers usually suffer a cost because they draw attention to themselves, but others around them benefit since they can escape.

Question 14

ground squirrels alarm calling

Answer 14

dispersal is sexually asymmetric. females remain close to natal burrow, but males disperse. females are expected to alarm call more since they are around more of their relatives.

Question 15

kin recognition

Answer 15

the ability to identify relatives, and assess genetic relatedness. permits kin selection

Question 16

kin selection

Answer 16

a form of natural selection, where individuals engage in self sacrificial behaviour that benefits the genetic fitness of relatives. Gives the actor indirect fitness.

Question 17

kin recognition systems

Answer 17

production of kin phenotypic labels or cues
sensory perception of label and and comparison /matching
action by individual

Question 18

kin recognition mechanisms in ground squirrels

Answer 18

odours from oral and dorsal glands.
they can discriminate based on scent, and can tell if they are kin even if they had never encountered the related individual.
explored non kin odours longer

Question 19

sweaty t shirt study

Answer 19

women preferred the body odours of men who had dissimilar MHC genes from their own

Question 20

4 mechanisms of kin recognition

Answer 20

location (indirect): treat any individual in nest as kin.

association/familiarity (indirect): treat any individual you are familiar with as kin. works if raised in family groups, so phenotypes are reliable cues

phenotype matching (direct): individuals inspect and learn certain phenotypes of their relatives and use these to recognize kin if encountering unknown individuals

self referent phenotype matching (armpit effect, direct): learn your phenotype, to later compare or match unknown phenotypes with your template

Question 21

cuckoo tactics

Answer 21

brood parasites- keep watch over nest hosts and once eggs are laid, replace host’s egg with their own, which is colour matched. (Mimetic eggs)

Question 22

brood parasite adaptations

Answer 22

must choose host species and time their egg laying, remove egg when they lay their own

mimetic eggs

short egg incubation time and fast chick growth rate

Question 23

counter adaptation of brood parasite hosts

Answer 23

choose nest sites that are hard to parasitize, territory defence

morning incubation

mottled eggs (Distinct pattern)

ejection (puncture or grasp eggs)

brood desertion

Question 24

host parasite arms race, cuckoos

Answer 24

cuckoos have different host races, and each race lays distinct eggs that best mimic their specific host.

Question 25

cuckoo host co-evolution

Answer 25

do hosts reject different eggs? experiment

common hosts all discriminated against a model egg that didnt match except for dunnocks (new host)
other suitable host species showed more rejection than common hosts
unsuitable species didn’t discriminate against
species with smaller bills suffer greater rejection cost (damage to own eggs) so usually deserted. species with large bills would eject.

Question 26

mechanisms of host rejection

Answer 26

desertion and ejection

desertion: time and energy to start new clutch

ejection: may not be physically possible, may damage own eggs, may mistakenly eject own eggs

Question 27

why dont hosts discriminate chicks if they can discriminate eggs?

Answer 27

not adaptive to discriminate chicks, and also dont have the same frame of reference as they do with eggs as cuckoo chicks ejects all other eggs when hatched.

cost of recognition errors (accidentally learning parasite is own young and rejecting own young in future)

Question 28

costs of being a host in brood parasitism

Answer 28

time and energy raising parasite
recognition errors (may toss out own chicks/eggs)
ejection itself is hard (cuckoos often choose smaller species who cant eject without damaging other eggs)
abandonment costs (starting over, but you may get parasitized there too.)

Question 29

parasite chick trickery

Answer 29

have redder mouths naturally to signal more hunger
larger, appear in better condition
their begging call matches that of multiple chicks