This module is made up of four concepts. The goal of the first concept is to elicit an understanding of primate relatedness, phylogeny, and how specific characteristics are beneficial for life in an arboreal environment. The next concept explains the overarching trends in hominin evolution and the selective pressures that encouraged their development. Concept three examines specific fossils and the characteristics that are associated with them. This concept serves to provide a timeline of hominin evolution. The final concept encourages students to understand characteristics in the hominin lineage and how they relate to social behaviors. This concept ends by driving home the point that evolution is a dynamic and continual process.