Evolution education is of increasing interest to the science education community. This special issue of the "Journal of Research in Science Teaching" has been devoted to the subject of evolution. The following articles are included: (1) "Evolution: Biological Education's Under-Researched Unifying Theme" by Catherine L. Cummins, Sherry S. Demastes, and Mark S. Hafner; (2) "Conceptions of Natural Selection: A Snapshot of the Sense-Making Process" by John Settlage, Jr; (3) "Identifying Critical Junctures in Learning in a College Course on Evolution" by John E. Trowbridge and James H. Wandersee; (4) "Evolution in Secondary School Biology Textbooks of the PRC, the USA, and the Latter Stages of the USSR" by Frederick A. Swarts, O. Roger Anderson, and Frank J. Swetz; (5) "A Study of the Presence of Evolutionary Protoconcepts in Pre-High School Textbooks" by Kodi R. Jeffery and Linda E. Roach; (6) "Teaching Evolution and Natural Selection: A Look at Textbooks and Teachers" by Maria Pilar and Jimenez Aleixandre; (7) "From Down House Landlord to Brazilian High School Students: What Has Happened to Evolutionary Knowledge on the Way" by Nelio Marco Vincenzo Bizzo; (8) "Conceptualizing a Teaching Experience on the Development of the Idea of Evolution: An Epistemological Approach to the Education of Science Teachers" by Ruth Zuzovsky; (9) "The Great Evolution Trial: Use of Role-Play in the Classroom" by Jonathan Duveen and Joan Solomon; (10) "Comments and Criticism"; (11) "Point: Belief, Understanding, and Teaching of Evolution" by William W. Cobern; and (12) "Counterpoint: Belief, Understanding, and the Teaching of Evolution" by Mike U. Smith. (ZWH)