Chemistry and kinematics of stars in dwarf galaxies

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Are dwarf galaxies the same as the protogalactic fragments that merged to form large galaxies, as described in the hierarchical galaxy formation models?    Was the Galactic thick disk formed through disk heating by a merger at an intermediate epoch?  How similar are the star formation histories of the dwarf spheroidal galaxies to the gas rich dwarf irregular systems?    Questions such as these can now be addressed through detailed chemical analyses of the individual stars in the low-mass dwarf galaxies in the Local Group, made possible with the large 8 to 10-m class telescopes and high efficiency spectrographs.  My research involves the determination of the chemical composition of old stars in dwarf spheroidal galaxies and young stars in dwarf irregular galaxies.   Currently, comparisons of stars in dwarf galaxies with similar stars in our  Galaxy show very little in common, but we are on the verge of a breakthrough as results from the multi-object spectrographs begin to emerge.   Analyses of hundreds of stars per dwarf galaxy allow us to examine hierarchical galaxy formation, as well as test our assumptions about stellar nucleosynthesis in general.  The next generation of telescopes and instrumentation will make it possible to reach the old stars in the more isolated dwarf galaxies for the first time, which may be different from the nearby systems that we are currently able to study, as well as stars in more distant dwarf galaxies such as those orbiting the Andromeda galaxy and possibly those in the Virgo cluster.