I will discuss our programs to quantify how two important processes -- galaxy mergers and gas accretion from the surrounding intergalactic medium -- affect the evolution of galaxies. I will focus on two samples that provide important markers of such evolution: post-starburst (or E+A) galaxies and extended Lyman alpha nebulae (Ly-alpha blobs).

First, I will describe our project to construct a detailed timeline of how the stellar, gaseous, dust, and nuclear components of galaxies evolve during galaxy-galaxy mergers. Mapping the evolution of these baryonic components over time is now possible with the precise post-starburst ages that we obtain via a new UV-optical spectral-photometric fitting technique.

Second, I will introduce our work to identify galaxies forming via gas-accretion at high redshift. While Ly-alpha blobs are the best candidates for such galaxies, even their basic properties --- their energy sources, spatial distribution, number density --- are poorly understood. I will present initial results from complementary wide-field and deep surveys for Ly-alpha blobs, suggesting that blobs are extremely rare and strongly clustered, and thus the likely precursors of present-day brightest cluster galaxies.