Life on Earth appears to be dominated by higher plants and animals. Yet an immense variety of microbial eukaryotes swarm in the foliage, grass, soil, bogs, ponds, streams, lakes, and oceans. These inconspicuous organisms are flagellates, algae, ciliates, sarcodines, slime molds, apicomplexans. This assemblage is generally termed the protists. Our course is to build a comprehensive picture of protistan diversity. The major steps of eukaryotic evolution will be in focus. By tracking phylogenetic affinities in protistan lineages we will elucidate the major branches on the tree of eukaryotic life.