Altruism and Theory Flashcards
What is kin selection?
Kin selection is an evolutionary force which favours the evolution of traits, or persistence of genes, because of their net beneficial effect on the survival of offspring of genetic relatives.
What is Hamilton’s Rule?
The conditions under which altruistic behaviour will spread via kin selection.
rB > C, where:
r = Relatedness
B = Benefit to recipient
C = Cost to donor
In order for offspring production:
B / C must be greater than relatedness of donor to own offspring / relatedness of donor to recipient’s offspring
Reproduce yourself or help your parents reproduce?
relatedness of donor to own offspring = 0.5
relatedness of donor to recipient’s offspring = 0.5
0.5/0.5 = 1
Therefore, you should help your parents reproduce if with your help they can produce more than 1 offspring.
Reproduce yourself or help your mother reproduce with a new mate?
relatedness of donor to own offspring = 0.5
relatedness of donor to recipient’s offspring = 0.25
0.5/0.25 = 2
Therefore, you should help if more than twice as many offspring are produced.
Reproduce yourself or help your aunt reproduce?
relatedness of donor to own offspring = 0.5
relatedness of donor to recipient’s offspring = 0.125
0.5/0.125 = 4
Therefore, you should help if more than 4x as many offspring are produced.
Explain the prisoner’s dilemma in game theory
Cheat and snitch on the other prisoner:
- Other prisoner remains silent, you are released.
- Other prisoner snitches, both get a medium sentence.
Cooperate:
- Other prisoner remains silent, you will get a short sentence.
- Other prisoner snitches, you get a long sentence.
The best scenario, when you are selfish, is to always cheat when you don’t know what the other player will do, i.e. selfish non-cooperation is the best strategy, even when net population benefits are higher under cooperation. Suggests that true altruism cannot exist.
What is an evolutionary stable strategy?
If an ESS is adopted by the majority of the population, it cannot be beaten by an alternative strategy.
What are the conditions for non-kin altruism evolving? (Tit for tat conditions)
1) Altruistic act has a relatively low cost, as high costs encourages selfishness.
2) Benefit exceeds the cost.
3) Defecation leads to punishment (e.g. loosing cooperative benefits).
4) Encounter rate probabilities between individuals are high (spatial clustering).
5) Individuals recognise each other (higher animals).
What is reciprocal altruism?
Behaviour that temporarily reduces an animal’s fitness whilst increasing another animal’s fitness, with the expectation it will be reciprocated in the future.
