Week 13: Kinship and cooperation and non kin

Question 1

cooperation

Answer 1

Comes from latin ⇒ together (co) + to work (operari)

Question 2

altruism; how are C/B measured?

Answer 2

a type of cooperation where one individual help another but they incur a cost while the other receives a benefit
- Costs and benefits are measured in terms of reproductive success
- cost to actor but benefit to recipient
- widespread in animal behavior and easy to evolutionarily explain

Question 3

mutualism

Answer 3

benefit to actor and recipient

Question 4

selfishness

Answer 4

benefit to actor and cost to recipient

Question 5

spite

Answer 5

cost to actor and cost to recipient

Question 6

Group selection

Answer 6

acting for the good of the species; People viewed as naturally group oriented, acting selfishly only when socialized to do so by a particular ideology (capitalism)
- widespread view in animal behavior through the 1970s
- Still common in folk wisdom, social sciences, nature documentaries, some biologists

Question 7

Wynne-Edwards

Answer 7

wrote Animal dispersion in relation to social behavior in 1962
- Argued that many animal behaviors are adaptations to the group rather than the individual
- Population have self regulating mechanisms

Question 8

self restrain hypothesis

Answer 8

David lack argued that birds laid optimal clutch size for their current environment, and that probability of survival was not independent of clutch size
- Increased clutch: too many mouths to feed
- Decreased clutch: fewer to start with, fewer to survive

Question 9

what did studies to test the self restrain hypothesis find?

Answer 9

biologists not generally view clutch size as a solution for optimizing genetic fitness

Question 10

what are animals put on earth to do? (3)

Answer 10

• Eat
• Grow
• Reproduce ⇒ eat and grow to reproduce

Question 11

why do animals have babies?

Answer 11

Animals make babies in order to make copies of their genes
- To make copies of themselves? ⇒ No, babies aren’t perfect copies
- Individuals only last a lifetime but genes endure for many generations

Question 12

why do animals take care of their babies? (3)

Answer 12

• To help their babies survive to adulthood
• So they can make babies of their own
• And thus copies of mom and dads genes

Question 13

what would happen if there was a gene for altruism?

Answer 13

on average genes for indiscriminate altruism will go extinct, while genes for carrying selectively for offspring will become common

Question 14

when is group selection possible? (2)

Answer 14

• High rate of group extinction
• Low rate of migration among groups ⇒ genes stay in groups
  (mathematically, group selection is just a subset of kin selection)

Question 15

what should group selection be contrasted with?

Answer 15

people commonly contrast group selection with individual selection but really the contrast is with gene level selection
- People seem to think that group selection is somehow nicer than gene level selection
- Group selection requires high rates of group extinction, meaning intense intergroup competition ⇒ war

Question 16

Inclusive Fitness

Answer 16

the sum of direct fitness and indirect fitness, minus the help from others advancing your own fitness
- Usually refers to fitness of alleles, not individuals
- Not the same as physical strength and athleticism

Question 17

Direct fitness

Answer 17

reproductive success with the number of offspring surviving to the average first year of reproduction

Question 18

Indirect fitness

Answer 18

the individual’s influence on the direct fitness of genetic relatives, weighted for each relative by the coefficient of relatedness between the two

Question 19

Hamilton’s rule

Answer 19

refers to the probability that a gene for helping kin will evolve
- An allele favoring altruistic behavior can evolve if the altruistic behavior is generally directed toward individuals that are also likely to share that allele by common descent

Question 20

key variables of hamiltons rule? (3)

Answer 20

• Cost to donors direct fitness (C)
• Benefit to recipients direct fitness (b)
• Coefficient of relatedness between donor and recipient (r)

Question 21

what is the equation for Hamiltons rule?

Answer 21

c<br
- Given a range of options chose br-c = max

Question 22

coefficient of relatedness (r)

Answer 22

probability that the alleles at a particular locus chosen at random from two individuals are identical by descent

Question 23

how do you calculate coefficient of relatedness?

Answer 23

1. Identify all paths by which focal individuals are connected => Paths may go up from one individual and down to the other (Only up once, down only once)
2. For each path, identify coefficient of relatedness for that path =>ceach step is ½ and multiply values for each step along a given path
3. If focal individuals are connected by more than one path, add the R’s for each individual path

Question 24

how many genes do grandkids have of each parent in diploids?

Answer 24

1/4
- in sexual diploid species, each offspring has half of the genes of each parent

Question 25

why are kin social with one another?

Answer 25

related individuals cooperate - non human primate groups are sometimes hundreds of years old

Question 26

cooperative breeding

Answer 26

kids stay at the nest to help out with the next set of babies ⇒ temporarily foregoing their own reproduction

Question 27

why do birds have cooperative breeding more than mammals? (2)

Answer 27

- birds don't lactate - older siblings can help feed offspring

Question 28

Eusociality

Answer 28

reproductive division of labor ⇒ with or without sterile castes - Overlapping generations - Cooperative care of young

Question 29

Haplodiploidy

Answer 29

one of the offspring types are haploid rather than diploid like the other offspring

Question 30

is haplodiploid necessary or sufficient for evolution of eusociality?

Answer 30

its neither - Appears to favor evolution of eusociality - Ancestral state of eusocial lineages generally seems to be monogamy

Question 31

what is the relatedness of sister and brother bees?

Answer 31

sister relatedness is ¾ but brother relatedness is ¼

Question 32

how does eusociality work in non insect species?

Answer 32

Often eusociality in non insect species is a temporary thing depending on environmental circumstances - siblings take care of younger siblings

Question 33

ways to estimate relatedness (3)

Answer 33

- Spatial association ⇒ anyone in the vicinity as kin (especially for the phylopatric sex) - Social association ⇒ anyone that you grew up with - Phenotype matching ⇒ treat anyone who looks/smells/behaves identical as kin

Question 34

Kinship systems

Answer 34

humans recognize familial relationships on both sides of the family - Every human society has terms for recognizing these relationships

Question 35

do animals and humans need conscious knowledge of kinship to behave differently toward kin?

Answer 35

no

Question 36

what makes some individuals worth more to an actor?

Answer 36

their reproductive expendancy - Age, fertility, and other qualities

Question 37

Paternity certainty

Answer 37

whether a father knows if the offspring is their own ⇒ the mother typically knows but the father less likely knows - The degree of cooperative care provided by older generations to an offspring is calibrated by paternity certainty

Question 38

which older generations are the most and least likely to take care of offspring?

Answer 38

maternal grandmother is most likely and paternal grandfather is least likely

Question 39

when will two individuals participate in an exchange?

Answer 39

as long as b-c>0 - some likelihood that the person will pay you back later - If actions are reciprocated then they both zero out

Question 40

necessary conditions for reciprocity? (2)

Answer 40

- Repeated interactions - Traits that make individuals more likely to engage in mutual exchange and avoid exploitation

Question 41

what traits make an individual more likely to engage in mutual exchange? (3)

Answer 41

- Individual recognition - Memory - Accounting of balances punishment of cheaters

Question 42

how common are clear cases of reciprocal altruism in animals?

Answer 42

very rare - We need to be careful about repayment because payment may come in different currencies

Question 43

what do vampire bats do for reciprocal altruism?

Answer 43

They die if they fail to feed 3 nights in a row - They share blood with bats ho haven't fed

Question 44

do bats share with non relatives?

Answer 44

Happens with relatives and non relatives - food sharing occurs with non kin and is not a maladaptive byproduct - Bats may get social bonds through this where they exchange other forms of help - Vampire bats have large brains

Question 45

Tragedy of the commons

Answer 45

when you have a village and there is a nice common space that people can raise sheep, if someone raises more sheep and wipes the grass out everyone is hurt - this requires some restraint by each person to keep the resource for everyone - intergroup encounters and conflicts are common ⇒ different species have different ways of overcoming the collective active problem

Question 46

CAP

Answer 46

collective action problems

Question 47

solutions to cap

Answer 47

Punishment - for humans ⇒ death - For other species it depends on the context, but there is no punishment for failure to participate in an intergroup conflict => Punishment does not happen in the context of intergroup conflict (warfare) but punishment happens in other social ways

Question 48

why might someone not participate in collective action/

Answer 48

There may not be a collective action problem to begin with ⇒ ex: if someone is wounded, then how are they supposed to participate in the battle when they cannot afford to fight - We need to document if they are on equal footing to begin with - non participators are starting off with lower energy ⇒ participants have higher energy and can afford to participate with extra calories to spare

Question 49

what does male rank allow for? When do male coalitions form?

Answer 49

reproductive success; When there are multiple males in a group male coalitions will form in certain species because there is male dominance - achieving high rank and maintaining high rank for reproductive success may require coalitions with other males

Question 50

what type of male hierarchies do males typically have?

Answer 50

linear or transitive - Whole point is access to mating opportunities ⇒ shapes male fitness

Question 51

how do males have a higher rank with maturity?

Answer 51

they have more social net worth - Use social relationships as coalitions to achieve higher rank later on - More sociality means more reproductive success

Question 52

when might alpha males have to concede mating?

Answer 52

for support form other males - The more support lover ranking males provide, the higher the amount of reproductive chances they get

Question 53

what prevents mating skews?

Answer 53

coalitions, female synchrony, and choice - Males can only effectively monopolize one female at a time but when many are ready for mating at once this makes it more difficult for males to do that - Females also show preferences toward certain males ⇒ rank, protection, food resources, infanticide, etc.

Question 54

what do coalitions need to be successful?

Answer 54

large asymmetry - Targets don’t fight back when asymmetry is high - successful coalitions will maximize rank differences within them so certain males don't challenge later on - which male is able to access the female after the conflict results in mostly one male mating with the female

Question 55

types of coalitions? (3)

Answer 55

- All down conservative - bridging - all up revolutionary

Question 56

All down conservative

Answer 56

higher ranked males gang up against the ones below them

Question 57

briding

Answer 57

males higher and lower ranked than a certain individual gang up against them

Question 58

all up revolutionary

Answer 58

low ranking males gang up on higher ranking males ⇒ reduces skew among males - the second ranking male typically challenges the high ranking male - The high ranking male may recruit another lower ranked male against the second male

Question 59

how do coalitions form in regard to fighting ability?

Answer 59

Coalitions are formed such that asymmetry in fighting ability is maximized - Mid ranking males form more coalitions than low ranking males - tend to go to the male who contributed more competitive ability - Reciprocal altruism, but strong asymmetry due to different bargaining power

Question 60

end card

Answer 60

:)