  Recent years have seen a series of large-scale photometric surveys with the
aim of detecting substructure in nearby dwarf galaxies. Some of these objects
display a varying distribution of each stellar population, reflecting their
star formation histories. Also, dwarf galaxies are dominated by dark matter,
therefore luminous substructure may represent a perturbation in the underlying
dark material. Substructure can also be the effect of tidal interaction, such
as the disruption of the Sagittarius dSph by the Milky Way. Therefore,
substructure in dwarf galaxies manifests the stellar, structural and kinematic
evolution of these objects.
