This exercise allows students to share a common and exciting scientific experience; use of a sequence database to analyze an unknown sequence. Specifically, the students learn to use database searching for identification of an organism and its close relatives. Students are provided via e-mail with ribosomal RNA sequences from organisms unknown to the students. They are directed to access the GenBank nucleotide sequence database, search it using their sequences, and then analyze the data to identify the organism from which the sequence was derived. Students are also asked to identify close relatives of the unknown and evaluate the degree of divergence between their unknown and its relatives.