Evolution is simply a character change in a population over time.
*Biological* evolution requires that this change have an underlying, heritable (genetic) basis.
However, behaviors can also change through 'cultural evolution' without any genetic foundation.
What many fail to recognize is that evolution is exclusively a population-level phenomenon - individuals cannot 'evolve'.
Evolutionary change can only be confirmed by measuring changes in quantifiable character sets among populations over time, or among populations that have been geographically separated for some period.