Kin Selection

Question 1

Altruism

Answer 1

an action that reduces an individuals own fitness while increasing the fitness of another individual

Question 2

inclusive fitness

Answer 2

Direct Fitness (# offspring) plus equivalents gained through support

Question 3

Nash Equilibrium

Answer 3

best strategy given others responses

a strategy that is the best response, given other participant’s responses –> no-one benefits further unless multiple participants agree to change their strategies

Question 4

Evolutionarily Stable Strategy

Answer 4

a strategy that cannot be invaded by a rare mutant using an alternative strategy

a special case of Nash equilibrium

Question 5

Prisoners Dilema

Answer 5

Turn in for 0 charge, confess for chance at min charge, or get turned in and face full charge

Nash equilibrium: best strategy given others strategy so if your partner talks you should talk and if they don’t you shouldn’t either

Question 6

Cooperatively Breeding

Answer 6

some members forego reproduction while in the group, help elsewhere

May risk death by defending the colony.
Devote energies toward rearing of young of others (helping at the nest).

Question 7

Eusocial

Answer 7

individuals cooperate in the care of young

There is reproductive division of labor, with sterile (or nearly sterile) workers assisting fecund individuals.

Question 8

Kin Selection (Hamilton 1963)

Answer 8

Selection acting on individuals related through recent, common descent

Question 9

Hamiltons Rule

Answer 9

Fitness = direct fitness + r x fitness effect on relatives

Fitness = direct fitness + indirect fitness

Inclusive Fitness

Question 10

Hamilton’s Rule (CONT)

Answer 10

c = cost to altruist
b = benefit to altruist relatives
w = fitness if selfish

Question 11

prairie dog watcher

Answer 11

acting selfishly because he has least chance of being eaten

Question 12

Haplodiploidy

Answer 12

Females develop from fertilized eggs (Diploid)

Males develop from unfertilized eggs (Haploid)

Question 13

Reciprocal Altruism

Answer 13

Altruism is rewarded with altruism

Defectors are ‘punished’ because they do not receive cooperation in the future (ex. vampire bats)

Question 14

Cost of helping

Answer 14

fitness when not helping - fitness when helping

Question 15

Benefit

Answer 15

fitness when helped - fitness when not helped

Question 16

what is the formula for fitness if being altruistic?

Answer 16

w - c + r x b

Question 17

when should you act altruistically?

Answer 17

c fitness if selfish

Question 18

what is r?

Answer 18

relatedness, r, the probability that two individuals share a particular allele
group members are more similar to one another than to members of other groups

Question 19

how do you figure out relatedness of siblings for haplodiploids?

Answer 19

chance the mother gave the chromosome to the kid x the chance the kid picked the mothers chromosome = (1/2)(1/2) = 1/4 related to sibling

change dad gave the chromosome x chance kid picked the chromosome = (1)(1/2) = 1/2 related

total relatedness = (1/4) + (1/2) = 3/4 related

females are more related to their sisters than their daughters! r = .75 vs r=.5