This article describes the use of an enquiry-based approach to the study of human evolution in a practical context, integrating role-playing, jigsaw cooperative learning and scientific argumentation. The activity seeks to unravel the evolutionary relationships of five hominids and one ape from rather "messy" evidence. This approach enhanced the motivation of the students when learning about evolution, as well as fostering their understanding of the nature of science and their appreciation of the role of cooperative learning in science contexts. (Contains 2 figures and 2 tables.)