Editing Behavioral ecology (section)

===Evolutionarily stable strategy===
In short, [[evolutionary game theory]] asserts that only [[Strategy (game theory)|strategies]] that, when common in the population, cannot be "invaded" by any alternative (mutant) strategy is an ESS, and thus maintained in the population. In other words, at equilibrium every player should play the best strategic response to each other. When the game is two player and symmetric, each player should play the strategy that provides the response best for it.

Therefore, the ESS is considered the evolutionary end point subsequent to the interactions. As the fitness conveyed by a strategy is influenced by what other individuals are doing (the relative frequency of each strategy in the population), behavior can be governed not only by optimality but the frequencies of strategies adopted by others and are therefore frequency dependent ([[Frequency dependent selection|frequency dependence]]).

Behavioral evolution is therefore influenced by both the physical environment and interactions between other individuals.

An example of how changes in geography can make a strategy susceptible to alternative strategies is the parasitization of the African honey bee, [[African bee|''A. m. scutellata'']].