The diversity of microscopic life forms, both prokaryotic (bacteria and archaea) and eukaryotic (protists, fungi, phytoplankton), will be explored. The evolutionary forces responsible for this diversity will be described in detail and contrasted to those at work in macroscopic eukaryotes. Students will learn about the molecular methods used to identify and classify both culturable and non-culturable microbes, and genetically characterize entire populations. Prerequisites: BIOL 107 and 108 or SCI 100, and a 200-level Biological Sciences course. MICRB 265 recommended.