Elephant Tusks and Natural Selection: Leveraging Naïve Student Models to Identify and Address Misconceptions Surrounding Biological Evolution

Biological evolution remains an instructional challenge for U.S. science educators. A 2019 Gallup poll, for example, reports that nearly 40% of American adults continue to reject evolutionary theory in favor of purely creation-centered worldviews (Brenan, 2019; Miller et al., 2022). For the science teacher, who must already navigate the philosophical and theological objections of parents and students, a contentious public discourse only generates additional pedagogical challenges. By the time students enter the secondary science classroom, they have often inadvertently adopted common but false beliefs regarding the rate of evolutionary change, the amount of scientific evidence in support of evolution, and the capacity for an individual organism to rapidly adapt to its changing environment. These misconceptions not only hamper students’ ability to develop accurate conceptual models but serve to buoy the various arguments that teachers must address if students are to ultimately accept accurate models of evolutionary theory (Rudolph & Stewart, 1998; Rutledge & Warden, 2000).

To counter misconceptions within abstract scientific topics such as evolution, national reform documents, including the Next Generation Science Standards (NGSS), prescribe lesson sequences that simultaneously mimic the work of scientists and act as critical grounding experiences for students (NRC, 2012; NGSS, 2014). The curricular shift has been noteworthy, with many contemporary lesson sequences centering concrete exploratory and explanatory activities (e.g., Janney et al., 2022; Kidd et al., 2023). Evolutionary theory, unsurprisingly, has received significant curricular attention, resulting in numerous concrete instructional interventions that target key conceptual ideas such as natural selection, coevolution, inheritance, and genetic variation (e.g., Reynolds, 2019; Wilcox et al., 2017).

Alone, however, even exceptionally designed instructional sequences are unlikely to fully eliminate deeply held misconceptions surrounding evolution and other complex topics, unless they are explicitly addressed. Longstanding research in student conceptual change suggests that for learners to avoid rejection or false accommodation (accepting a modified version of the accurate model and/or accepting the accurate model only in “school” settings), they must first identify inconsistencies within their own models (Appleton, 1993). To do so, science teachers must not only draw out student thinking through questioning, but simultaneously scaffold students toward the rejection of false ideas. Unfortunately, when it comes to abstract science concepts, students are adept at “classroom camouflage,” capable of imitating a deep level of understanding, even if it is only surface level. Thus, it can be difficult for science teachers to assess and address individual misconceptions in large classrooms in real time.

This article puts forth Naïve (pre-instruction) Student Modeling as a simple, yet effective instructional strategy designed to draw out early student sensemaking, and present opportunities through which students begin to question the legitimacy of their explanations surrounding complex scientific phenomena such as evolutionary theory.

Class action research conducted during the 2019 spring semester in seventh-grade honors science classes found some benefit to engaging in naïve model development prior to moving into more concrete experiences. A mixed-design ANOVA indicated that mean conceptual growth between pre- and posttests was statistically significantly greater for lesson sequences that utilized naïve modeling before a concrete experience than sequences that began with a concrete experience [F (1,1) = 7.508, p = .007]. (Figure 1).

In the following example of Naïve Student Modeling, biological data surrounding tusk growth patterns in elephants in response to poaching is used to reveal early student misconceptions surrounding evolutionary theory (Table 1). As students clarify, present, and scrutinize their initial models, they not only begin to identify inconsistencies within their own thinking, but they also provide critical insight to the instructor prior to engaging in more content-specific activities.

Genetic bottlenecks arising from anthropogenic environmental disturbances can offer an effective way to explore evolutionary ideas in the science classroom. Perhaps most famously, a dramatic uptick in the phenotypic frequency of industrial melanism in “Peppered Moths,” due to heavy environmental damage caused by the newly industrialized United Kingdom of the 19th century, offers an often oversimplified but powerful example of natural selection driving population change (Cook et al. 1999).

A less well-known, yet similar evolutionary phenomenon has occurred in some African elephant populations. Global demand for ivory has long driven catastrophic poaching activity, with some estimates suggesting an annual mortality rate of nearly 30,000 (Bale, 2020). However, intense ivory harvesting, which resurged during the 1970s and 1980s, resulted in even more significant regional African elephant declines, with some populations experiencing losses upward of 50–90% (Chiyo et al., 2015). Though there is significant natural variability in tusk size due to genetic and environmental factors, poachers are thought to more frequently target older adult males. This results in an age-striated downward selection pressure, making smaller tusks dramatically more prevalent in these populations. Specifically, these elephant populations have observed an overall reduction in tusk length and circumference, and an increased expression of the typically rare and potentially X-linked tusklessness gene among females, which causes them to have no tusks at all (Campbell-Station et al., 2021).

An overall reduction in tusk size may have unpredictable ecological implications for African elephants. Large tusks are useful for foraging, clearing access routes to nutrient-rich vegetation, stripping bark from trees, and digging for water. By using their tusks, elephants regularly reshape their environments, producing downstream effects for smaller organisms. It is unclear how significant alterations to elephants’ physiology and behavior may impact their broader ecosystem (Maron, 2018). For the biology student, the story of the African elephant is compelling, not only because elephants are well-known charismatic megafauna, but also because this case-study perfectly illustrates the convergence of anthropogenic evolutionary pressures with currently advantageous, yet almost certainly detrimental, trait expression.

Requiring that students expose their thinking surrounding a new topic is nontrivial. For one, students rarely consider scientific phenomena in their everyday lives. They also place themselves at heightened social risk by expressing potentially incorrect lines of thought. It is crucial that educators seeking to make effective use of naïve student models increase opportunities for students to honestly reveal their thinking while maintaining a classroom environment in which they feel comfortable doing so.

Prepare students to engage in naïve modeling. We have found it useful to spend the preceding class period introducing the structure of the activity, establishing classroom norms, and discussing expectations for participation (Table 2). As students will ultimately evaluate the ideas of their classmates, it is crucial that they are shown how to properly critique ideas without falling into personal attacks. Historical examples from science including the purported rivalry of Sir Issac Newton and Robert Hooke, debates about the structure of the solar system, and the complex politics surrounding Watson and Crick’s triple helix model of DNA can be useful stories to draw on when discussing proper and improper strategies for scientific debate.

Introduce poaching as a key ecological threat to African elephants and other megafauna. The level at which poaching is explored may vary according to student age and previous exposure to global ecological challenges. Various media sources can function as useful introductory material (articles, videos, etc.). For example, Fobar (2023) offers insight into potential economic drivers specifically related to elephant poaching. The introductory material should meet the following objectives:

1. Identifies poaching as a detrimental human activity driven largely by economic factors.

2. Discusses the role of poaching in funding regional conflicts.

3. Discusses the ecological implications of heavy poaching in terms of population dynamics and trophic-level interactions.

Note: At this stage, students should not be presented with any introductory material that describes behavioral or physiological changes that elephants have experienced because of poaching pressures. It is crucial to leave this unaddressed for students to first attempt to unpack on their own.

Pose two overarching questions to students: (a) What have been the historical impacts of poaching on the African elephant? and (b) How is poaching causing these changes? Use a projector or whiteboard. Provide each student group with the set of data presented in Figure 2 (adapted from Chiyo et al., 2015; Maron, 2018). Additionally, provide each student an “Initial Model Development” page (Figure 3) and ask students to record the overarching questions. The figures highlighted in this lesson are only examples. At the instructor’s discretion, alternative data sets may also be useful in displaying long-term trends in African elephant physiology.

Present the following set of instructions:

1. Examine the data carefully. Interpret each piece of data individually, then as a group.

2. Discuss any conclusions that can be reached from each figure.

3. Work with your group to respond to the following prompts: (a) What have been the historical impacts of poaching on the African elephant? and (b) Explain how poaching is causing these changes.

4. Using the “Initial Model Development” page, sketch or describe your group’s responses. Include as much detail as possible.

In our experience, students typically require 30–60 minutes to (a) make sense of the data, (b) discuss its implications, and (c) put forth a detailed explanatory model. Monitor student groups carefully by listening to discussions, interpretations, and conclusions to ensure that groups remain focused. Ask clarifying questions (Table 3) to each group, allowing students to speak freely without correction or input, utilizing neutral verbal and physical responses to increase student response rate. Make mental note of their explanations. It is not uncommon for students who are accustomed to a Teach-Practice-Apply classroom model to look to the instructor for approval, and some students may become visibly uncomfortable with the lack of a conclusive response. However, the objective at this stage is not to ensure total comprehension, but to provide students the opportunity to explore their own sensemaking. That students experience some discomfort with their own explanations will be useful in this activity.

With guidance, most groups will correctly ascertain that African elephant populations under heavy poaching pressures tend to experience an overall reduction in tusk size and circumference, and an increased expression of the tusklessness phenotype (no tusks at all). However, when prompted to explain this connection, student answers often fail to show the evolutionary connection between natural selection and gene expression. Some common student explanations include:

1. As poaching increases, African elephants grow smaller tusks to reduce their chances of being targeted by poachers.

2. As poaching increases, African elephants physically reduce or remove their tusks (typically through some form of “brushing” with rocks or trees) to avoid being targeted by poachers (Figure 4).

3. As poaching increases, African elephants choose to have offspring with smaller tusks to protect them from poachers.

Note how each explanation suggests an intentional avoidance strategy on the part of the elephants rather than the natural outcome of selective pressures. Students often draw on their own experiences when problem-solving and will similarly anthropomorphize animal responses. Even explanation 3, which appears to suggest an at least rudimentary understanding of natural selection, is not drawing a succinct connection between selective culling and reproductive success. Instead, like explanations 1 and 2, explanation 3 inaccurately implies an active form of decision-making on behalf of the animal. Students frequently reference the data or the elephants’ desire to survive as supporting evidence despite there being no clear connection between this “evidence” and the explanation put forth in their model. They must be made skeptics of these more obvious logical flaws before proceeding into deeper conceptual ideas of evolutionary theory. Otherwise, they are at increased risk of false accommodation in which they attribute adaptation to anthropomorphized decision-making.

Ask each student group to present their models to their classmates. As groups present, encourage other students to contribute questions or comments that either support or challenge their classmates’ ideas. Carefully monitor participation for respectful and meaningful conversation. Student interactions should foster dialogue and elicit useful and insightful criticism so that individuals may begin to notice potential weaknesses in their proposals—planting seeds of doubt. For students to abandon their prior inaccurate notions surrounding evolutionary theory, they must, of their own accord, begin to doubt their legitimacy. To generate effective student dialogue, prior to beginning the activity, scaffold students toward appropriate interactions by asking questions such as

• How useful would it be for students who share ideas if I just responded with, “Your idea is bad”?

• What if I just said, “I like your idea”?

• What types of questions or comments might be more useful? Why?

• Why might we want to focus our comments on people’s ideas and not on their character?

Continue to maintain impartiality during presentations, even if students note key flaws in their own models or those of their classmates. For example, it is not uncommon for students to question the cognitive capability of elephants to connect their tusk length to their risk of being poached when such an idea is presented. However, it is still critical at this stage to withhold approval of specific student ideas to continually foster a classroom environment where learners do not solely rely on the teacher as the sole source of information, but instead become comfortable with intellectual uncertainty. Record student observations and arguments on the whiteboard for later use. Ask students to meet with their groups again to make immediate adjustments to their explanatory models following classmate critique, advising them to be prepared for further reflection and revision as they proceed throughout the unit. With naïve sensemaking regarding evolutionary theory clarified for the student and made visible to the instructor, it is now appropriate to move students into more typical concrete experiences.

When generating naïve explanatory models for a complex phenomenon such as elephant tusk reduction, students will often inadvertently use what are vaguely defined and poorly constructed notions of evolutionary theory. When tested, even by their equally misinformed classmates, these models generally crumble due to inherent flaws in logic. Their weakness is an important tool for the classroom science teacher who, with careful mediation, can leverage the students’ desire for understanding as a powerful weapon in combating misconceptions. With seeds of doubt priming students to abandon previously held notions of evolution, subsequent concrete experiences will be significantly more impactful as students have already begun the crucial process of integrating scientifically accurate models. The strategy of using naïve explanatory models preceding a concrete experience is not solely limited to evolutionary theory and can be applied to a variety of complex scientific topics such as the phases of the Moon, Earth’s seasons, and states of matter. For these and other topics, the process should be as follows:

1. Introduce a scientific phenomenon with data.

2. Provide students the opportunity to generate naïve explanatory models.

3. Encourage classmate critique, and discussion.

4. Allow students to reconsider their initial models.

5. Begin concrete learning experiences.

Revealing naïve student sensemaking surrounding evolutionary theory and other abstract science topics without significant educator interference requires attentive mediation, a well-established level of trust between the instructor and their students, and careful instructional planning. The strategy, although effective, is accompanied by some risk. If proper scaffolding and support are lacking, students may (a) adopt inaccurate models presented by their classmates, (b) solidify incorrect ideas, or (c) opt out of participation due to frustration, confusion, or fear of judgment. The teacher must be acutely aware of their students’ capabilities, provide carefully tailored scaffolding, and monitor their classroom to avoid pitfalls (e.g., students attacking individuals rather than ideas). However, if done properly, students and teachers will find the strategy to be challenging, engaging, and useful in the elimination and replacement of misconceptions with scientifically accepted models.