Click on the link below to start the lab.

http://www.hhmi.org/biointeractive/activities/shells/gallery.html

Learning Objectives:  to organize a set of 20 shells into categories, create an evolutionary tree (cladogram) based on this classification system, to realize that superficial similarities do not always indicate close evolutionary relationships.

Key Concepts: dichotomous keys, cladograms (phylogenetic trees), taxonomy, evolution.