The discussion above highlights the power of stellar population synthesis to infer mean stellar properties from integrated light, and constrain galaxy formation models. Presently, well tested stellar population synthesis models can be used to determine mean stellar ages and abundances of Fe, Mg, Ca, C, and N. The recent addition of the latter two elements may spark the emergence of a more complex picture of galaxy formation. In order for that to happen, more work is needed to refine chemodynamical models used to interpret the abundance measurements and their relation with global galaxy properties in terms of the physics of galaxy formation. There has been very promising recent progress on this front, which, due to space limitations, could not be reviewed here (e.g., Arrigoni et al. 2010, Pipino et al. 2009a, b). More theoretical work is also needed to develop better stellar population synthesis models to ascertain the reality of current abundance determinations, and to include more elements in the pool of reliable abundances. On this front as well, different groups are making steady progress (Lee et al. 2009, Coelho et al. 2007, Peterson 2007). In that regard, it is particularly desirable to extend stellar population synthesis modelling towards the UV, in order to match the upcoming observing capabilities that will make possible collection of large samples of galaxy spectra at redshift beyond 2. With the expected developments in theory and observations, this field will likely go through very exciting times in the next decade.
The author thanks Yonsei University and the organizers, especially Suk-Jin Yoon and Sukyoung Yi, for a truly delightful workshop. The hospitality of the Department of Astrophysical Sciences at Princeton University, where this paper was partly conceived, is warmly acknowledged. Conversations with David Spergel, Charlie Conroy, Jenny Graves, Inger Jørgensen, and Richard McDermid contributed substantially to the formulation of some of the ideas presented in this paper. This work was supported by Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., on behalf of the international Gemini partnership of Argentina, Australia, Brazil, Canada, Chile, the United Kingdom, and the United States of America.