Evolution is the basis for all biological processes and is the lens through which we understand the living world, and a comprehensive understanding of evolution is necessary to understand biology and to be a scientifically literate citizen. Unfortunately, science teachers do not consistently teach evolution as an overarching concept in biology, if it is taught at all (Berkman & Plutzer, 2015; Sickel & Friedrichsen, 2013; Veal & Kubasko, 2003). Therefore, students often have a weak understanding of evolutionary theory and do not understand its importance in biology and in everyday life (Catley, 2006). This includes biology majors, who have been found to exhibit initial naïve conceptions of natural selection; even after an instructional intervention, only 30% of students demonstrated a complete lack of misconceptions regarding natural selection (Nehm & Reilly, 2007). This lack of understanding extends to genetic drift (Andrews et al., 2012), macroevolution (Abraham et al., 2012), phylogenies and tree-thinking (Phillips et al., 2012), and other evolutionary mechanisms and associated concepts.

Students enter introductory biology with certain conceptions about evolution that are often based on factors other than scientific evidence, such as identification with denialist positions (Darner, 2019), anti-evolution positions, prior education, and personal beliefs (Chi et al., 2012). The theory of conceptual change asserts that naïve conceptions are deeply rooted within students’ conceptual frameworks, which are shaped by these prior life experiences (Duit & Treagust, 2003). To access and potentially change these naïve conceptions, course material needs to be made relevant to students’ lives in order to prompt conceptual change. However, students rarely view evolution as an important topic in their lives. This likely leads them to engage in educational experiences that could facilitate evolutionary understanding only for the sake of fulfilling expectations of schooling, which is unlikely to facilitate genuine conceptual change. Teaching methods that elicit students’ naïve conceptions and provide anomalous evidence that contradicts students’ previously held theories to prompt conceptual change have shown positive gains in student engagement with evolutionary theory in their daily lives (Heddy & Sinatra, 2013).

The initial conceptual change model suggests that, after experiencing cognitive dissonance via dissatisfaction with the current framework, students should be exposed to another framework that is intelligent, plausible, and fruitful (Posner et al., 1982). This framework must explain the phenomena being investigated to a greater extent than their previously held framework, make sense to the student, be able to be believed by the student, and allow the student to understand similar concepts (Duit & Treagust, 2003). If these conditions are met, then accommodation of the framework may follow. However, accommodation is not the only possible outcome; several other possibilities have been proposed to occur when learners encounter anomalous data (Chinn & Brewer, 1998; Hemmerich et al., 2016). The strategies (usually employed unconsciously) are used by individuals to deal with anomalous evidence and include ignorance, rejection, expressing uncertainty about its validity, excluding it as irrelevant, holding in abeyance, reinterpretation to fit the naïve framework, acceptance leading to peripheral theory changes, and acceptance leading to complete accommodation of another theory (Chinn & Brewer, 1998). Thus, complete theory change is only one of several possible outcomes of presenting students with anomalous evidence, and many of the other potential outcomes do not result in the learner abandoning their inaccurate framework entirely and fully accommodating the scientific model. While numerous science teaching strategies may result in progress toward conceptual change, this result is ultimately immaterial if students do not perceive the content as relevant to them and worthy of retention and further use. Therefore, in order to truly access students’ preexisting framework and have the opportunity to accommodate a scientific framework, it is necessary to make the material relevant to students’ daily lives (Dole & Sinatra, 1998).

We argue that if evolutionary theory is taught and understood in relation to individuals’ daily lives, students will be better equipped to make informed decisions regarding socioscientific issues. An understanding of evolution has the potential to illuminate issues such as the reality of one’s impact on biodiversity and habitat destruction, the role of biotechnology in medical and agricultural contexts, the phenomenon of antibiotic resistance and responsible antibiotic use, and the shared evolutionary history of all species. Thus, comprehension of these evolutionary ideas may foster more thoughtful and scientifically informed decision-making in nonscientists.

The theory of conceptual change and the principle that quality science education should be related to students’ day-to-day lives is the basis for the Teaching for Transformative Experiences in Science (TTES) model (Pugh, 2002). This model is grounded in Dewey’s ideas of students’ active engagement and experiences being essential components of changing one’s perception about a topic. The TTES model describes transformative experiences as a situation in which students seek opportunities to use scientific ideas outside of class in ways that enable them to integrate scientific ideas into their schema, resulting in an expanded perception of a natural phenomenon encountered in their everyday lives. This experience prompts an appreciation for the scientific idea’s applicability to everyday contexts, empowered by this expanded perception (Pugh, 2011). In short, transformative experience is posited as three components that mutually support one another (1) active use (AU), (2) expansion of perception (EP), and (3) experiential value (EV) (Figure 1).

The TTES model was previously used to foster transformative experiences in undergraduate education majors with limited biology backgrounds over the course of a three-day instructional treatment (Heddy & Sinatra, 2013). This treatment consisted of differential evolution instruction being provided to comparison and treatment groups for one hour each day, for a total of three hours over the three days. Both groups received lectures on the concepts of adaptation, variation, inheritance, speciation, domestication, and extinction in the first session. The lecture delivered to the treatment group included examples of AU, EP, and EV, based on the instructor’s experiences for each evolutionary concept. At the end of the first session, students were asked to attempt to apply the six evolutionary concepts outside of the classroom before the second session in order to facilitate discussion on the applicability of these concepts to “real life.” During the second session, students discussed how they used the evolutionary concepts and identified how their experiences fit into the components of the transformative experience. At the end of the session, students were again asked to find ways to use these evolutionary concepts outside of class. The third and final session was very similar to the second, in which the instructor and students shared experiences, identified instances of AU, EP, and EV, and discussed how the evolutionary ideas were useful in daily life. The TTES model resulted in significantly higher scores on the Transformative Experience Survey (TES) and significantly higher posttest scores on a conceptual change instrument for the treatment group than the comparison group (Heddy & Sinatra, 2013).

Based on the positive gains elicited in three days in the study described, we believe that nonscientists’ worldviews toward science, evolution in particular, can be greatly enhanced through implementation of the TTES model in a semester-long, introductory biology course with instruction focusing on students’ transformative experiences regarding evolutionary concepts. This course will hereafter be referred to as the TTES/E course to denote that instruction is being guided by the TTES model in order to elicit transformative experiences and increase conceptual understanding of evolution.

After taking an introductory biology course taught from the TTES/E perspective, to what extent do students:

1. actively use evolutionary concepts in their daily lives?

2. expand their perceptions of natural phenomena when applying evolutionary concepts?

3. acknowledge the experiential value of evolutionary concepts in shaping their worldview?

This study took place at a public, four-year, large (approximately 20,780 students), primarily residential, R2 institution in the midwestern United States. Data collection occurred in a special section of introductory biology for nonmajors designed to be taught entirely from an evolutionary perspective. This course used the TTES model and research-supported methods of increasing students’ conceptual knowledge to teach introductory biology with evolution as a unifying concept, demonstrating how evolutionary mechanisms have contributed to the structure of the living world. One of the ultimate goals of this course was to foster conceptual change and transformative experiences in a group of general education students.

The TTES/E course addressed the same concepts taught in general education sections of the course, but was structured around the evolutionary principles of adaptation, variation, inheritance, speciation, domestication, and extinction as in prior literature using the TTES model (Heddy & Sinatra, 2013). These evolutionary principles have been proposed to underlie the common essentialist misconception that species are fundamentally unchanging entities (Shtulman, 2006), leading to the argument that these principles are critical for understanding evolution (Shtulman & Calabi, 2012). Therefore, this framework was useful in assessing students’ misconceptions about the evolutionary principles as they relate to essentialist thought.

This course met twice a week for an hour and 50 minutes per session and did not have a separate lab section taught by another instructor; rather, the instructor (first author) integrated lab activities throughout the semester. The course was structured as a flipped classroom, in which students watched and took notes on lecture videos online using a provided outline prior to class. These lecture videos presented the biological content typically taught in the course and six additional lecture videos were specifically dedicated to presenting the evolutionary principles. Class activities were designed to relate one of the six evolutionary principles to the biological concepts embedded in that unit and were embedded with a priori questions designed to practice AU, EP, and EV of the evolutionary principle being addressed. Written reflection questions completed after class discussion of the evolutionary principle were designed to prompt students to consider how the evolutionary principles relate to the world around them in order to elicit AU and EP, and how these principles relate to their lives and collective scientific knowledge in order to elicit EV. Specific examples of questions and prompts for the evolutionary principle of variation can be found in Table 1.

Participants in this study were consenting students in the TTES/E course, which was designated as an honors course, meaning that all participants were members of the university honors program. This was arranged in order to ensure that written responses would be high quality and suitable for qualitative analysis. Participants were all first-year students with an average ACT score of 29.3. Sixteen students consented to participate in this study.

At the conclusion of the course, 15 selected-response items and three open-ended questions from the TES (Heddy & Sinatra, 2013) were administered using Qualtrics (Table 2). The selected-response items were Likert-scored, with 1 meaning “strongly disagree” and 6 meaning “strongly agree.” Reliability of the Likert-scored items was high (15 items; α = 0.9529). The active use subscale consisted of nine items (α = 0.906), the expansion of perception subscale consisted of two items (α = 0.9207), and the experiential value subscale consisted of four items (α = 0.9245). Two items were eliminated from the expansion of perception subscale due to low internal reliability. Each open-ended question was intended to encourage student responses regarding each dimension of transformative experiences.

After administering the survey, student responses were averaged for each subscale (AU, EP, and EV) and descriptive statistics were calculated on each mean. For each subscale, a single-sample t-test was used to compare the mean score for that subscale to a score of 4 on a Likert scale, which corresponds to “slightly agree.” This analysis allows us to see if participants agree with statements significantly greater than “slightly” on any single dimension of transformative experience.

Written responses to the three open-ended questions were coded using NVivo, version 12. Responses were coded using the coding scheme used by Heddy and Sinatra (2013), in which responses were coded for level of out-of-school engagement. In this coding scheme, responses were scored on a scale of 0 to 3, in order of increasing evidence of out-of-school engagement. A score of 0 was assigned for responses that were not understandable, responses that indicated that the student did not engage in AU, EP, or EV, or no response. A score of 1 was assigned for responses that indicated that the student engaged in AU, EP, or EV in class, but showed no evidence of engagement outside of class. A score of 2 was assigned for responses that indicated that the student engaged in AU, EP, or EV, outside of class, but did not give a detailed description of the situation(s) in which they did so. Finally, a score of 3 was assigned for responses that indicated that the student engaged in AU, EP, or EV outside of class and provided a specific example of how they did so. Both authors independently coded the responses. Cohen’s κ was used to determine interrater reliability for all subscales. There was moderate agreement between coders on all subscales (κ_AU = 0.663, κ_EP = 0.525, κ_EV = 0.619). All coding differences were discussed, and consensus was reached on all responses. Following coding for out-of-school engagement, responses were also coded inductively for themes in how students applied evolutionary principles to their daily lives.

Students’ mean Likert scores on the active use items of the TES were significantly higher than 4 on the Likert scale, which corresponded to “slightly agree,” t(15) = 2.695, p = 0.017 (Figure 2). Students were also asked, “Give an example of how you used or thought about the evolution ideas you learned.” Of the 16 responses provided for this question, nine students were coded as a 2 or 3, meaning that students stated that they used evolutionary principles outside of class either with or without a specific example. One student explained their active use of evolutionary principles as, “After class, when talking to my parents or boyfriend, I would tell them about the cool evolutionary ideas I learned in Bio class. Things were just very interesting.” This response, coded as a 2, showed that the student was thinking about and explaining evolution to other people in their lives outside of class. Another student shared, “I follow science subreddits, so it’s interesting to apply what I’ve learned to the different posts about plants and animals that show up in threads.” This demonstrates that the student was specifically applying evolutionary ideas to various plants and animals that they encountered in their daily lives through social media; this response was coded as a 3.

Open coding of students’ written responses revealed two themes (Table 3) in how students apply evolutionary theory to their everyday lives: enhanced observations of the natural world, specifically a concept of interconnectedness, and discussing evolution in social interactions. The two responses above were coded as discussing evolution in social interactions. Another student responded, “When I look around at nature now, I can think about how biodiversity has effected [sic] it all. I think about how it all has gotten there, and what mutations it had to go through to be the lucky species.” We interpret this as evidence of evolutionary ideas enhancing one’s observations of the natural world and how species impact one another.

Students’ mean Likert scores on TES items asking about expansion of perceptions of natural phenomena, given understandings about evolutionary theory, were also significantly above “slightly agree,” t(15) = 3.3297, p = 0.00457 (Figure 2). When asked, “Give an example of how your experiences have changed due to learning the evolution ideas,” 10 out of 16 students shared responses that were coded as a 2 or 3. Students’ statements of their expansion of perception coded as 2 included, “I often look at species and think about what common ancestor they probably stemmed from. I look at species differently, and I think about them more,” and “I think about how things around me have evolved when I never did in the past.” Responses coded as 3 included a student sharing that their knowledge of evolutionary principles impacted how they view socioscientific issues, expressing that “Political issues like global warming are in a clearer light for me since I’m now better able to look at the issue through the lens of evolution.”

Open coding of students’ written responses revealed two themes (Table 3) in how aspects of students’ worldviews have changed as a result of learning about evolution. One of these themes recurred from the active use section, which was enhanced observations of nature, specifically a concept of interconnectedness. A theme of theory change also emerged in this section, which we coded when a student explicitly stated that an aspect of their prior worldview was changed as a result of instruction. As an example of theory change, one student stated, “I really didn’t know a lot about evolution, in fact I really believed that evolution and religion couldn’t coincide, but after this course, I have a much better understanding of what evolution really is and why its [sic] more than just a theory.” Another student shared, “Well I always thought that humans evolved from chimps, when really we just share a common ancestor. That redefined my existence and if I never learned that I would still be going around telling people we evolved from something that we in fact did not.” Both of these responses were coded as 3, in addition to theory change.

Students’ mean Likert scores on TES items asking the extent to which they acknowledge the experiential value of evolutionary theory were also significantly above “slightly agree,” t(15) = 3.345, p = 0.0044 (Figure 2). In response to the question “Give an example of how you may value the evolution ideas you have learned,” eight students provided responses coded as a 2, while 5 students provided responses coded as a 3.

Within responses coded as 3, one student made a connection between evolution and the importance of conserving biodiversity in the face of probable extinction, stating, “I learned things are more than likely going to die before they have the time to evolve, so we should try to protect and minimize our destruction and impact on their habitats.” Another student expressed, “I value the evolution ideas I’ve learned in that I can understand the importance of seeing how people are more than just their heritage or where they come from. Learning about evolution has made me more open-minded.” This demonstrates that the student values evolution for explaining the shared evolutionary history of all humans and the social implications of that knowledge. Other students conveyed that this knowledge would be valuable in their future careers and personal lives, evident in statements such as “I intend to focus on biological anthropology, so I will be constantly discussing human evolution and the ideas taken from this class on evolution will help contribute to my understanding of greater human evolution,” and “I value the ideas about evolution that I have learned, because I am now a deeper learner. I like to learn about how species have morphed over time. I would like to learn about my ancestry, and where I came from. I would use the stuff I learned in this class to analyze my findings.”

Open coding of these responses revealed three themes (Table 3) regarding how students value evolutionary knowledge: the recurring theme of enhanced observations of nature, specifically a concept of interconnectedness; discussing evolution in social interactions, which recurred from the AU section; and increased understanding of science.

For several students, learning evolutionary principles fostered an appreciation for nature and the interconnectedness of the world around them. One student expressed, “Honestly, I just enjoy knowing these facts about life on earth and how it all connects and came to be. Evolution is an amazing process that intertwines all life on earth in some way and I value that I’m now able to understand how it does that.” Similarly, another student stated, “I value it because I just feel so much more intelligent. I know how things connect, and just how important things are, the species. It is so cool how everything connects. I have a new appreciation for our earth and the species on it.”

Within the theme of discussing evolution in social interactions, students shared that they “will know how to rebut an argument against evolution,” “understand evolution better now and could explain some concepts to others,” and “[are] able to use these ideas that I’ve learned to become more informed and inform others.” Students also expressed that learning about evolution has allowed them to learn more about science, evident in statements such as, “The evolution ideas I’ve learned have helped me to learn more over all [sic] and have clarified topics of science that I’ve learned my entire life but never completely grasped.” Another student appreciated the role of mutation in evolution, sharing “I now understand exactly how evolution occurred, because I wasn’t entirely sure how mutations occurred and why they did.”

The results of the TES reveal that students applied evolutionary theory to their lives to a moderate degree after instruction through the TTES model (Figure 2). A one-sample t-test showed that scores on each dimension were statistically significantly higher when compared with an average response of 4, representing “slightly agree.” This demonstrates that the TTES model can lead to a greater appreciation for evolution in nonbiology majors. Many of the responses indicate that students are actively using evolutionary ideas in their daily lives, using evolutionary ideas to expand their perception of the world, and appreciating the impact that understanding evolution can have on their lives. Further analysis of this qualitative data will provide insight into future incarnations of this curriculum and biology instruction as a whole. While these results are very promising for the efficacy of the TTES model in prompting students to apply evolutionary theory to their daily lives, a few limitations exist. This study took place in a small section with 20 students enrolled, which likely increased the strength of the student-teacher relationship. The investigator in this study was the instructor of the course, which may have impacted student responses. This section was also composed entirely of freshman honors students, so we cannot generalize our results to a larger undergraduate population who are usually provided biology instruction in large enrollment courses. Further redesign, scaling up, and reimplementation of this course is planned to take place over the next several years.

Nonetheless, we do feel these findings offer suggestions to instructors who are interested in structuring courses to foster transformative experiences. First, it is essential that course materials integrate examples of scientific ideas in everyday, nonscientific contexts in order to model transformative experiences. We have found the National Center for Case Study Teaching in Science (NCCSTS) library to be a powerful resource in connecting science to life outside of the classroom. Sharing personal examples of transformative experiences, either from the instructor or from previous students, also serves the purpose of demonstrating the experiential value of scientific concepts. Further, we argue that science education must support students’ feelings of autonomy and competence in order to facilitate active use of scientific ideas, so laboratory activities for this course were designed to give students opportunities to interact with authentic data to construct meaningful conclusions. Finally, employing metacognitive strategies such as the weekly reflection questions employed in this study is likely to help scaffold students’ transformative experiences.