Prof. Zaritsky, in collaborations including UA undergraduate and graduate students, is undertaking a variety of programs on galaxy structure and evolution. These programs range from finding the lowest mass galaxies in and around the Local Group, to using the most dark matter dominated large galaxies in the Universe to test models of dark matter, to searching for the existence of intermediate mass black holes in dwarf galaxies, to exploring the effect of dust distributed in the halos of galaxies on cosmological measurements.