Rapid Growth of Massive Galaxies: A Paradox for Hierarchical Formation Models

On behalf of the survey teams I summarize the designs and results of the Las Campanas Infrared Survey and Gemini Deep Deep Survey, both of which were initiated to understand the nature of red galaxies and to study the history of stellar mass assembly. Our results from luminosity function analysis, ISM absorption line measurements, and spectral synthesis modeling show that near-infrared selected galaxies at 1<z<2 are not only massive and abundant but also old and metal enriched, indicating rapid formation of massive systems at higher redshifts.