Fig. 5

Phylogenetic tree showing the hypothesized relationships for nine animal phyla. a Inferred from morphological and developmental characters (based on Freeman 2005, Figure 31.10); b inferred from molecular characters (based on (Freeman 2005), Figure 31.13). In a closed book laboratory exercise, students are asked to map each of three characters onto each of these two trees. The characters are: (1) body cavity (acoelomate, pseudocoelomate, or eucoelomate), (2) number of opening to the digestive tract (one or two), and (3) segmented body (yes or no). As part of a lecture exam, students are asked to map each of four characters onto tree (a). The characters are: (1) body cavity (acoelomate, pseudocoelomate, or eucoelomate; the question asked on the Final Exam during S07, for which we have data, omitted asking about body plans), (2) embryological development (protostome or deuterostome), (3) true tissues, and (4) symmetry (radial or bilateral)