Evolution of Sociality Flashcards
Dilution Effect
Living in a group has the possibility of a predator eating someone other than you
Cooperative Foraging
Bigger group can handle big/tough things with less cost to energy
-Work together to get more food and expend less energy
Hamilton’s Rule
An altruistic allele increases when r x B > C
r; relatedness
B; benefit
C; cost
Inclusive Fitness
An individual can get copies of her genes into the next generation either by producing more offspring herself or by helping her kin in their reproductive endeavors
Eusociality
A single female or caste produces the offspring and nonreproductive individuals cooperate in caring for the young
Game Theory
When social conditions determine behavioral strategies
Evolutionary Stable Strategy
A behavior that, when adopted by most of the population, cannot be invaded by another strategy
Reciprocity
Mechanisms whereby the evolution of cooperative or altruistic behavior may be favored by the probability of future mutual interactions.
Group Selection
Differential fitness of groups causes some groups to outcompete others
Individual Selection
Differential fitness of individuals causes some genotypes to outcompete others
Hawk-Dove Conflict
V= Payoff
C= Cost of fighting
-Similar to Prisoner’s Dilemma (rewards and costs)
Zone of Conflict
When priorities are mismatched between parents and their offspring
-Parents try to value all offspring equally but also need to value themselves and their energy
Provide Costs and Benefits of Sociality
Benefits
-Dilution Effect
-Cooperative Foraging
Costs
-Parasite Load (living in close proximity, infections/parasites transfer a lot quicker)
-Decreased Reproduction Output (more competition for mates, especially in eusocial populations; ants and bees only have the queen mate)
What leads to Cooperation?
- Kin Selection
- Reciprocity
- Group Selection
Provide characteristics of eusociality
- Reproductive division of labor
- Cooperative rearing of young
- Overlapping generations
Explain haplodiploid sex determination
All males are haploid and all females are diploid
-Because of the genetics of haplodiploidy, when a queen in a colony mates with a single male, sister workers are related to one another on average by a coefficient of relatedness r of 0.75; that is, the probability that a given parental allele ends up in both sisters is 0.75
-The probability that the sisters share a given allele copy through their mother is 0.25 (as in the case of diploid species), but because all males are haploid, the probability that sisters share an allele copy through their father is 0.5
Explain Prisoner’s Dilemma
T= Temptation
R= Reward
P= Punishment
S= Sucker’s Payoff
-See where you have the most benefit, dealing high may have a bigger reward or a bigger consequence
Provide Examples of Conflict among Kin
Offspring value contributions to self more than to siblings (offspring only care about themselves and about the parent feeding them but does not care about their siblings)
Explain Honest versus Dishonest Signaling
-Honest signals are enforced by the community; community is more aggressive towards liars
-Honest signals tend to be more costly but are responded to
Altruistic
An action that has the immediate consequence of reducing an individual’s own fitness while increasing the fitness of another
