Social Behavior II (morality and eusociality) Flashcards
what is required for morality to evolve
- empathy
- care about wellbeing of others (prosocial tendencies)
- fairness
evolved morality - how would this evolve?
- Groups that have these traits are more cooperative, it would outcompete those who are not cooperative
- Multilevel selection
example of evolved morality
- 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
explain honest and deceitful signals
- there are not just present in sexual selection
- can be seen anytime there is a conflict of interest
honest and deceitful signals - conflict of interest
- parent vs offspring
- sibling
- non-kin
honest and deceitful signals: conflict of interest - parent-offspring
- 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
parent-offspring conflict - extra begging
- begging is physiologically demanding and dangerous
- when less related: there is more begging
- when more related - there is less begging
parent-offspring conflict: extra begging - research as evidence
- when a bird species evolves a higher level of extrapair mating (less related chicks)
- it also evolves louder begging by chicks
honest and deceitful signals: conflict of interest - sibling
- Siblings want to maximize fitness over the fitness of their siblings
- usually happens more when there is not enough resources
conflict of interest: sibling - explain the outcome and the direct vs indirect fitness
- Competing against sibling and killing them
- maximizes direct but minimizes indirect (when sibling conflict happens)
honest and deceitful signals: conflict of interest - non-kin
- 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
conflict of interest: non-kin - examples (non-humans)
- food sharing
- nest defense
- baboons help each other via mutual grooming
conflict of interest: non-kin - social contract in humans
- Prisoner’s Dilemma
- Both Cooperate: each gets half
- Both Defect: nobody gets anything
- One Cooperates and one Defects: defector gets all
non-kin: social contract in humans - long-term tactics
- always steal
- alternate between steal and split
- tit for tat: do what partner did last time
- but cheating is managed through punishment
non-kin: social contract in humans - game theory
uses mathematical equations to ask: can we predict how animals that have mutual interests should behave?
non-kin: social contract in humans - game theory modeling
- 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
define eusociality
- 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
what might select for eusociality
- kin selection: haplodiploid sex determination and monogamy
- ecology and life history
- multilevel selection
eusociality hypotheses - kin selection: haplodiploid sex determination
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)
kin selection: haplodiploid sex determination - how does this impact direct vs indirect fitness
- very high indirect fitness to help the colony
- females maximize inclusive fitness by acting as workers and investing in the production of sisters
kin selection: haplodiploid sex determination - challenges
- many eusocial animals are not haplodiploid
- many haplodiploid animals are not eusocial
eusociality hypotheses - kin selection: monogamy
- 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)
kin selection: monogamy - benefits and challenges
- 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
eusociality hypotheses - ecology and life history
- 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
eusociality hypotheses - ecology and life history example
- 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
