Definition of a biological species: a group of interbreeding (or potentially interbreeding) individuals, which can produce fertile offspring. A species is reproductively isolated from other groups. Purpose: Students will data of Ensatina eschscholtzii sightings collected by Dr. R.C. Stebbins to determine if his hypothesis that all Ensatina eschscholtzii found in California belong to one species. BACKGROUND: The small salamanders of the genus Ensatina are strictly Page