Title: Galaxy Evolution in the Spitzer Era: What Have We Learned?

Abstract: The Spitzer Space Telescope provides a unique view of distant galaxies by measuring the infrared emission from obscured star formation and AGN. I will discuss how Spitzer observations of cosmologically distant galaxies have improved our understanding of galaxy evolution. In particular, I will focus on recent results from several deep surveys, including GOODS, MUSYC, and AEGIS, which combine deep Spitzer data with multiwavelength ground-based observations, and data from the Hubble Space Telescope and the Chandra X-ray Observatory. I will also discuss Spitzer observations of gravitationally lensed distant galaxies, which provide a detailed view of very distant star-forming galaxies. The combination of these rich datasets provides new constraints on the assembly histories and black hole formation in distant galaxies. I will summarize these current constraints, and discuss challenges that remain to understand galaxy evolution.