Social Behavior II (morality and eusociality)

Question 1

what is required for morality to evolve

Answer 1

1. empathy
2. care about wellbeing of others (prosocial tendencies)
3. fairness

Question 2

evolved morality - how would this evolve?

Answer 2

• Groups that have these traits are more cooperative, it would outcompete those who are not cooperative
• Multilevel selection

Question 3

example of evolved morality

Answer 3

• Hadza hunter-gatherers of Tanzania
• researchers found that genetically related individuals resemble each other in their cooperability
• could lead to this evolve in a group selection framework

Question 4

explain honest and deceitful signals

Answer 4

• there are not just present in sexual selection
• can be seen anytime there is a conflict of interest

Question 5

honest and deceitful signals - conflict of interest

Answer 5

• parent vs offspring
• sibling
• non-kin

Question 6

honest and deceitful signals: conflict of interest - parent-offspring

Answer 6

• Offspring will want to keep getting resources from their parent longer
• But at some point, the parent wants to invest more resources to other children
• There is a gray area: parent-offspring conflict

Question 7

parent-offspring conflict - extra begging

Answer 7

• begging is physiologically demanding and dangerous
• when less related: there is more begging
• when more related - there is less begging

Question 8

parent-offspring conflict: extra begging - research as evidence

Answer 8

• when a bird species evolves a higher level of extrapair mating (less related chicks)
• it also evolves louder begging by chicks

Question 9

honest and deceitful signals: conflict of interest - sibling

Answer 9

• Siblings want to maximize fitness over the fitness of their siblings
• usually happens more when there is not enough resources

Question 10

conflict of interest: sibling - explain the outcome and the direct vs indirect fitness

Answer 10

• Competing against sibling and killing them
• maximizes direct but minimizes indirect (when sibling conflict happens)

Question 11

honest and deceitful signals: conflict of interest - non-kin

Answer 11

• cooperation and conflict
• can be explained by the social contract hypothesis used to explain kin selection
• there’s always have the option to defect but others may refuse to engage w cheaters and only w cooperators

Question 12

conflict of interest: non-kin - examples (non-humans)

Answer 12

• food sharing
• nest defense
• baboons help each other via mutual grooming

Question 13

conflict of interest: non-kin - social contract in humans

Answer 13

• Prisoner’s Dilemma
• Both Cooperate: each gets half
• Both Defect: nobody gets anything
• One Cooperates and one Defects: defector gets all

Question 14

non-kin: social contract in humans - long-term tactics

Answer 14

• always steal
• alternate between steal and split
• tit for tat: do what partner did last time
• but cheating is managed through punishment

Question 15

non-kin: social contract in humans - game theory

Answer 15

uses mathematical equations to ask: can we predict how animals that have mutual interests should behave?

Question 16

non-kin: social contract in humans - game theory modeling

Answer 16

• first, use mathematical models to determine best strategy
• then, ecologists see if it works w real animals
• finally, theorists refine their models when it doesn’t work

Question 17

define eusociality

Answer 17

• has 4 characteristics:
  1. adults live in groups
  2. cooperative care of juveniles (individuals care for brood that is not their own)
  3. reproductive division of labor (not all individuals get to reproduce)
  4. overlap of generations

Question 18

what might select for eusociality

Answer 18

1. kin selection: haplodiploid sex determination and monogamy
2. ecology and life history
3. multilevel selection

Question 19

eusociality hypotheses - kin selection: haplodiploid sex determination

Answer 19

females (workers) are more closely related to their sisters/queen’s daughters (r = 0.75) than they are to their won daughters (r=0.5)

Question 20

kin selection: haplodiploid sex determination - how does this impact direct vs indirect fitness

Answer 20

• very high indirect fitness to help the colony
• females maximize inclusive fitness by acting as workers and investing in the production of sisters

Question 21

kin selection: haplodiploid sex determination - challenges

Answer 21

• many eusocial animals are not haplodiploid
• many haplodiploid animals are not eusocial

Question 22

eusociality hypotheses - kin selection: monogamy

Answer 22

• when an individual can be certain that future siblings will be full siblings
• a new brother or sister increases an individuals fitness just as much as an offspring (r= 1/2)

Question 23

kin selection: monogamy - benefits and challenges

Answer 23

• benefits: in most (or all) lineages, females tend to mate w just one male
• challenge: not sufficient for eusociality to evolve. may not be important, could be correlated w other traits

Question 24

eusociality hypotheses - ecology and life history

Answer 24

• life history that may play a role:
  1. family groups in tunnels/nest and long term care of young
  2. food is not easy to get
  3. ecological limitations on dispersal

Question 25

eusociality hypotheses - ecology and life history example

Answer 25

• Hymenoptera
• all of them have haplodiploidy but only 4 groups evolved eusociality
• the eusocial groups all evolved nests and have extended larval care before eusociality evolved