Teaching and learning about the biological evolution: Conceptual understanding before, during and after teaching.

This study is part of a project with the main purpose of developing a teaching-learning sequence that enables the students to construct a scientific model of the biological evolution. Another purpose is to document the students’ conceptual development. Our theoretical background is the model of conceptual change initially proposed by Posner et al (1982). Here we focused on two key concepts in evolution – “variation” and “natural selection”. The development and the long-term retention of these concepts among Swedish students (16 – 19 years old) were studied. The students’ prior knowledge was investigated by a pre-test before teaching. During the teaching period some students were interviewed about these concepts, and small group discussions about the same concepts were videotaped. Approximately a year after teaching the students was given a delayed post-test. The majority of the students abandoned their prior ideas of strive and need, and adopted a more scientific view of these concepts. This was evident both in the interviews and in the post-test. The conceptual development of the interviewed students is discussed in the paper