  Culture evolves following a process that is akin to biological evolution,
although with some significant differences. At the same time culture has often
a collective good value for human groups. This paper studies culture in an
evolutionary perspective, with a focus on the implications of group definition
for the coexistence of different cultures. A model of cultural evolution is
presented where agents interacts in an artificial environment. The belonging to
a specific memetic group is a major factor allowing agents to exploit different
environmental niches with, as a result, the coexistence of different cultures
in the same environment.
