  A class of measure-valued processes which model multilevel populations
undergoing mutation, selection, genetic drift and spatial migration is
considered. We investigate the qualitative behaviour of models with multilevel
selection and the interaction between the different levels of selection. The
basic tools in our analysis include the martingale problem formulation for
measure-valued processes and a generalization of the set-valued dual
representation introduced in Dawson-Greven (2014). In particular we describe
the ergodic behaviour of these processes and review some situations under which
deme level selection determines the long-time behaviour.
