Description: This site, provided by David and Wayne Maddison of the Departments of Entomology and Ecology and Evolutionary Biology, of the University of Arizona, is "designed to contain information about the phylogenetic relationships and characteristics of organisms, to illustrate the diversity and unity of living organisms, and to link biological information available on the Internet in the form of a phylogenetic navigator." It does this via a browsable and searchable tree of phylogenetic categories. Users can follow the detailed tree or use an express page to get to a specific life group or organism. This is a complex site, and users are advised to study carefully the description of the project and help pages. It is a site that is awesome in its ambition, as well as its content.