Teaching evolution is a tricky business. Less teaching seems to give better understanding of the theory. Evolutionary processes are dialectic relations between many actors, individuals, groups, abiotic and biotic factors etc., different from mechanistic descriptions of relations between singular objects in other scientific theories. This difference, in combination with religious beliefs confuses efforts to get understanding and acceptance of the theory of evolution. With the new curriculum for Swedish compulsory school, science education has to be linked to students’ own experiences in order to promote critical thinking and skills useable in daily life. Further, biology in science teaching during the first school years is focused on general observations and fundamental concepts, not on scientific methods and evolutionary processes. Thus, students often experience biology as a subject filled with facts about simple relations and teleological explanations, making the theory of evolution superfluous. The objectives here were to design teaching in evolutionary theory adapted to the professional needs of students and to assess the learning outcome. Three different courses in evolutionary theory were included. Two pre-service teacher training programs, for nursery school and for year 4–6 in the compulsory school, and one for students in environmental studies were included. Assessments of learning outcome were made by analyses of texts written by the students. The quality of the science knowledge content and the personal and professional development were assessed by using the 4 R’s of Doll. Associations between concepts and understanding were evaluated using clustering and ordination statistical techniques. The learning outcome was good showing visible progressions in the understanding. Thus, it is important to assess the understanding of concepts rather than estimating their frequency in students texts.