Game Theory

frequency dependent selection

in which an allele has a greater selective advantage when it is rare than when it is common in the population.

types of frequency dependent selection

predation and reproduction

frequency dependent predation

hunting morphs/alleles of prey that are most common until population variation switches (blue jays and moths skinner box)

frequency dependent reproduction

rare male effect: a male with a rare phenotype enjoys more than his expected share of matings.

negative assortative mating

when animals mate with others with different or opposite phenotypes/genotypes than them

role of frequency dependent selection

maintaining genetic variation in a population

Evolutionary stable strategy

the optimal strategy for an individual to follow when the rewards (called payoffs) depend on what others are doing

why are ESSs important?

an optimal strategy that increases fitness of an individual

Mixed ESSs

when there are two or more strategies in a population in a stable equilibrium

Mixed ESSs ex

Digger v nest stealer wasps, reproductive strategies of male lizards, orange, yellow, and blue

role of negative assortative mating

maintaining genetic variation as well as avoiding inbreeding; strains of mice identifying kin from smell of urine

game theory

simulating how animals will behave in certain situations/using strategies

Frequency dependence

Benefits & costs of adopting a particular behavioral depend on the frequency of other strategies in a population

requirements for game theory models

1. currency → evolutionary fitness!

2. payoff matrix → determines behavioral strategies that evolve based on benefits and costs

payoff matrix

matrix of two strategies or two opponents

optimal strategy matrix

when the strategy with the highest payoff is along the diagonal

Pure ESS

all individuals adopt the same strategy and no other strategy can invade

types of adaptive behavioral strategies

cooperation, conflict/fighting, reproduction, communication, predator/prey