Abstract
This thesis proposes to make a significant contribution to the conceptual change literature. I investigate, from a developmental perspective, the manner in which students’ knowledge about evolution is constructed. Research in theories of conceptual change has taken two general directions: the coherent theory view (e.g., framework theory) or the fragmented knowledge view (e.g., “knowledge in pieces”). Much research on how people construct knowledge about evolution has taken a coherent theory perspective (Evans, 2000, 2001, 2008, et al., 2010; 2013; Gelman & Legare, 2011; Shtulman & Calabi, 2013). More recently however, Nehm and colleagues have argued that the nature of people’s emerging understanding about evolution is more fragmented than research has first suggested (Nehm & Ha, 2011; Ha & Nehm, 2014). Over a series of four studies, evidence suggests that people’s emerging understanding about evolution is developmentally staggered and that knowledge exists as fragmented knowledge rather than as coherent theories. The first study examined parent-child conversations from 52 families (with children aged 2- to 12-years) in a natural history museum. This study found that family museum visitors do not spontaneously discuss evolutionary concepts while visiting the natural history museum. For this reason, evolutionary exhibits that primarily use static displays need to make the topic of evolution much more apparent for parents and children to learn the intended contents. They would also benefit by including suggestions of wh- questions that parents could use to direct children’s attention to salient aspects of the museum displays. In the second study, I have adapted an existing coding scheme such that it would be more suitable to be used with novice learners, i.e., secondary school students (ages 12, 14 and 16, N = 106) when coding for their understanding about evolution. This study found that learning about evolution is context dependent where students are more likely to apply their knowledge about evolution to microevolutionary events than macroevolutionary events. These findings suggest that in teaching evolution, teachers and educators need to make the meanings of evolutionary terms (e.g., evolve, adapt, fittest) more explicit and use more different examples to support students in learning about evolution. In the third study, I report the findings of a teaching intervention that was aimed at helping students improve their understanding of evolutionary processes. One-hundred-fifty-nine students (ages 16 to 19) participated in this study. Comparing peer and individual learning strategies, this study found that peer learning was superior to individual leaning, but only when low level cognitive processes were involved. For cognitively more complex tasks, all students would benefit from receiving timely feedback from teachers or a more knowledgeable peer. Finally, the fourth study investigated whether or not understanding evolution was related to other aspects of everyday life (e.g., pro-environmental worldviews, affect about nature). There were a total of 148 adults who were included in this study. A positive relationship was found between people’s understandings about evolution and pro-ecological attitudes. This finding has potential implications on teaching for science literacy. Understanding how evolution works may be a gateway to people endorsing more environmentally friendly attitudes and behaviours. Evidence from the four studies suggests that there is a clear developmental trend throughout early childhood and mid- to late-adolescence in the way people reason about evolution. Whereas some concepts such as variation and selection are understood first, other concepts such as selection and time are less well understood. This is true even for young people 16 years and older. Potential implications on pedagogy are discussed.