Medically Relevant Activities in Evolution Education

Geoff Finch, Ecology and Evolution

Introduction

Research has suggested that feelings of interest and engagement in a subject as well as general academic performance as measured by, for example, attendance and grade, is partly predicted by levels of intrinsic and extrinsic motivation. Intrinsic motivation appears to be most closely associated with high performance and interest in understanding the material (Maurer et al. 2013). Levels of intrinsic and extrinsic motivation to learn are associated with learning outcome achievement (Maurer et al. 2013), and premed students have been found to be less intrinsically motivated to learn about science than non-premed students (Pacifici and Thomson 2011). My goal is to understand the effect of using medically relevant activities on the motivations of premed students in evolution in order to develop strategies to increase their motivation to learn. This project is conducted in an undergraduate evolution course that is required for biology majors.

TAR Questions

Does the use of medically relevant examples in learning activities improve comprehension of concepts in evolutionary biology for all students? Is there an especially pronounced improvement for premed students? Do premed students feel more motivated to understand the material after doing an active learning exercise with a medically relevant topic?

Approach / Methods

Students in this evolution course learn about several topics that are related to the evolution of cancer across the tree of life: the prisoners dilemma and the evolution of cooperation, major transitions in individuality, and the evolution of multicellularity. I designed an activity that uses Peto's paradox (Fig. X) to teach about these concepts. Peto's paradox arises from an expected positive relationship between the number of somatic cell division and rates of cancer occurence across the tree of life. In reality, large and long-lived species, such as elephants, do not exhibit elevated cancer rates relative to other species. To understand this concept, students work in small groups to play a game that simulates how cancerous cells emerge from somatic cell divisions. A second round of the game illustrates how particularly long-lived or large animals avoid cancer. Results of each group's game are visualized together to analyze trends across groups.

Fig. 2: A simplified depiction of the expected and observed trends in cancer incidence across animals, i.e. Peto's paradox

Fig. 1: The incidence of multicellularity and cancer or cancer-like phenomenon across the tree of life. Copied from Aktipis et al. 2015.

The objective of the activity is to impress on students the relevance of evolution to medicine while acheiving the following learning outcomes.

Students will be able to recall multilevel selection as a mechanism for the evolution of cooperation.
Students will recall the conditions for multicellular cooperation that must be violated to lead to cancerous growth
Students will be able to explain Peto's paradox and describe how somatic mutations can lead to cancer
Students will be able to explain how multilevel selection acts to favor the evolution of cooperation.

Following the activity, students completed a minute paper on the prompt, "Did you like this activity? Why/Why not?" These responses were analyzed for patterns associated with interest in the content and a sense of real-life relevance. Indications that students enjoyed the lesson because of the content are interpreted as preliminary evidence that medically relevant activities may increase motivation, interest in the topic, and consequently achievement of learning outcomes.

Results

In total, 156 minute paper responses were coded based on whether or not they enjoyed the activity and their stated reasons. Each response could receive multiple codes, including both positive and negative codes. The majority of codes (84%) were positive (Fig X). Positive- and negative-coded responses were broadly categorized as relating to course design or course content.

Course content

the majority of both positive and negative feedback was focused on the structure and delivery of the activity, rather than the content. Among positive responses that mentioned course content, the most common code was that relating to cancer or Peto's paradox (8.3% of total responses), and 3.8% of responses indicated that the content was generally interesting. These responses were anonymous, so unfortunately it is not possible to determine whether such positive feedback was more common among premed majors. Conversely, 3.2% of respondents found the activity to be boring or overly simple, 1.9% found it irrelevant, and 1.9% thought that it was not a good use of discussion time.

Fig. 3: Pie chart showing the proportions of positive and negative codes among all responses (n = 156).

Fig. 4: Summary of positive-coded responses. These illustrate the proportion of total responses that were assigned each code related to the design of the activity (top) and the content (bottom). Key words associated with each code are listed on the right.

Course design

The majority of responses were related to the structure of the activity. 35.9% enjoyed the activity because it was interactive or engaging. Many (31.4%) also indicated that this type of activity helped them learn concepts more effectively. Many responses (23.1%) described the activity as fun or appreciated that it felt like game. Among negative feedback, the most common themes were that aspects of the activity were unclear (12.2%) or that the results of the simulations didn't actually exhibit the expected trends associated with Peto's paradox (3.2%).

Fig. 5: Summary of negative-coded responses. These illustrate the proportion of total responses that were assigned each code related to course design or execution (top) and course content (bottom).

Discussion / Lessons Learned

Student responses to this activity were overwhelmingly positive. However, because of the emphasis on course design, the minute paper responses were not very effective in answering the question of whether the use of a medically relevant activity increased student motivation. Additional data will be necessary to assess this.

It is clear from student responses that they appreciated the interactive nature of this activity. This does offer some insight into the TAR question investigated here; perhaps the use of medically relevant examples (i.e. content) is less important for student engagement and motivation than the nature of the activity.

This project could be repeated with additional data more specifically assessing student reactions based on whether they are premed or not. Additionally, the prompt used for the minute paper response could be narrowed to encourage a greater focus on the content, so as to offer greater insight into the TAR questions investigated here.

About the Author

I am a PhD candidate in the Department of Ecology and Evolutionary Biology. I research drivers of chromosome number variation in plants, with a focus on desert species with very low chromosome numbers.

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