Book excerpt: Based on recent archaeological surveys and excavations, the chapters in this volume provide current, comprehensive, area-by-area summaries of the region's Precolumbian past. Research in the last two decades has indicated that the evolution and adaptations of the indigenous cultures of the region parallel those found elsewhere in Mesoamerica, from the simple Formative groups to the complex states of the North. The topics discussed in the book--areal and cultural syntheses and specific problems such as chronology, social organization, and economic systems--present much new information crucial to the understanding of cultural variations in Mesoamerica.