The Star Formation History of the Local Group
  The star formation histories of Local Group galaxies are summarized. The three large spirals are discussed individually, whereas the discussion of the Local Group dwarfs concentrates on differences and commonalities. While Local Group galaxies exhibit an amazing diversity in their star formation and enrichment histories even within the same morphological type, they share a number of common global properties. Major determining factors for their evolution are galaxy mass and environmental effects such as ram pressure and tidal stripping. It seems likely that low-mass dwarf irregular galaxies evolve into dwarf spheroidals. 
Eva K Grebel (University of Washington & MPI for Astronomy)