Kin Selection - 21

Question 1

In social interaction between two individuals, what are the four possible individual interactions

Answer 1

1. cooperation/mutualism
2. selfishness
3. spite
4. altruism

Question 2

Explain mutualism

Answer 2

both the donor and recipient increase fitness due to the interaction

Question 3

Explain selfishness

Answer 3

the donor’s fitness increases while the recipient’s fitness decreases

Question 4

Explain spite

Answer 4

both the donor and recipient’s fitness decreases

Question 5

Explain altruism

Answer 5

the donor’s fitness decreases while the recipient’s increases

Question 6

What is an example of selfishness

Answer 6

cannibalistic tadpoles eat cane toad eggs which was a good nutrition source for the tadpoles and reduces future competition

Question 7

Define inclusive fitness

Answer 7

both direct and indirect fitness

Question 8

Define direct fitness vs. indirect fitness

Answer 8

direct = an individual’s reproductive success
indirect = the reproductive success of relatives with the same genes

Question 9

Define kin selection

Answer 9

natural selection that favours the spread of alleles that increase INDIRECT fitness

Question 10

What is Hamilton’s Rule

Answer 10

that an allele for altruistic behaviour will increase if Br -C > 0 (benefit x coefficient of relatedness - cost > 0. or rearranged if r > C/B

Question 11

Explain the coefficient of relatedness (r) in Hamilton’s Rule

Answer 11

it is the probability that homologous alleles in two individuals are identical by descent

Question 12

Explain the example of Belding’s Ground Squirrels being an example of altruistic behaviour

Answer 12

the squirrels alarm call, but it was found that females call more than males in trill populations because more calls are done when daughters or granddaughters are nearby compared to cousins, or nieces that have a smaller r value

Question 13

Explain example of White-Fronted Bee-Eaters being an example of altruistic behaviour

Answer 13

nonbreeders pair with members of the group and help raise young, this happens because they have limited resources.
As the group size increased up to 6 per group, the amount fledging also increases. They found individuals to help more if they are more closely related too

Question 14

Explain the example of Cannabilistic Tadpoles as an example of altruistic behaviour

Answer 14

they prefer to eat non-kin (22/28 times they ate non-kin) even though they had no direct way of knowing if they were related or not

Question 15

What are the 4 ways that individuals are able to recognize their kin

Answer 15

1. indirect mechanisms (time/location - hatchlings in a nest)
2. phenotype matching (they look more like their parent’s traits)
3. vocal cues (sounding/making calls similar to the parent)
4. “recognition” genes (ex. MHC that produce glycoproteins that act as odor cues)

Question 16

What is the armpit effect and example

Answer 16

individuals learn what you smell like and others with a similar smell are relatives (because of the similar MHC genes)
ex. belding’s ground squirrel spend more time smelling individuals that are less related

Question 17

Define the greenbeard effect

Answer 17

allele frequency increases because individuals favour others known to have that allele too

Question 18

what are the 3 steps? needed for the greenbeard effect to occur

Answer 18

1. when an allele produces a greenbeard, meaning the allele can be recognized
2. when an allele produces the ability to recognize a greenbeard
3. when an allele discriminates based on presence/absence of greenbeard

Question 19

Explain the greenbeard effect using slime mold amoebae as an example

Answer 19

some of the cells form the stalk and sacrifice themselves on behalf of the cells that form spores
the csA protein on cell surface, sticks to other csA proteins to form the stalk, they produce the beard (csA proteins) -> recognizes other cells with beards (adhesion) -> and discriminate in labs not in soil??