National biology reforms often define evolution as the unifying concept in biology. However, few inservice teachers have an understanding of this role. The purpose of this study was to evaluate the effectiveness of a course sequence in evolution designed for inservice biology teachers on their conceptions of the role of evolution in biology. Twenty-two teachers attended a course for two quarters. The course covered the history and mechanics of evolutionary theory, included a 12-day field trip to the Galapagos Islands, and ended with a synthesis of course materials into classroom lesson plans. Teachers' views of the role of evolution in biology did not change as a result of the program. No significant change occurred in the number of the teachers who included evolution in their descriptions of biology (approximately 50%), with only two teachers recognizing the unifying role of biology. At the conclusion of the course, teachers were as likely to define evolution as a subordinate concept in biology as they were to describe it as the superordinate theory tying disparate biology topics into a coherent whole. Despite a course specifically designed to present evolution as the unifying theory in biology, the teachers were unwilling or unable to change previously held views of biology. (PR)