Analyzing change in students' gene‐to‐evolution models in college‐level introductory biology

Abstract

Research in contemporary biology has become increasingly complex and organized around understanding biological processes in the context of systems. To better reflect the ways of thinking required for learning about systems, we developed and implemented a pedagogical approach using box-and-arrow models (similar to concept maps) as a foundational tool for instruction and assessment in an Introductory Biology course on genetics, evolution, and ecology. Over the course of one semester, students iteratively constructed, evaluated, and revised "Gene-to-Evolution" (GtE) models intended to promote understanding about the connections linking molecular-level processes with population-level outcomes. In practice, a successful GtE model contextualizes information provided in a case study and explains how genetic-level variation originates at the molecular level, is differentially expressed among individuals, and is acted upon by the environment to produce evolutionary change within a population. Our analyses revealed that students' ability to construct biologically accurate models increased throughout the semester. Model complexity peaked near mid-term then subsequently declined. This suggests that, with time, students were building more parsimonious models, shedding irrelevant information, and improving in their ability to apply accurate and appropriate biological language to explain relationships among concepts. Importantly, we observed the greatest relative gains in model correctness among students who entered the course with lower mean GPA. In an analysis comparing performance among achievement tritiles, lower-performing students effectively closed the achievement gap with the highest performing students by the end of the semester. Our findings support the effectiveness of model-based pedagogies for science teaching and learning, and offer a perspective on pedagogical application of modeling strategies to foster systems thinking and knowledge structuring in college-level biology. # Momentum is growing among biology educators for rethinking our approaches to teaching and learning in college-level biology. In particular, there is interest in employing strategies that help students transition toward a way of thinking that is more reflective of contemporary

Modeling with a Conceptual Representation: Is It Necessary? Does It Work?

“…Additionally, our data indicate that students begin the modeling task by representing their current ideas or hypotheses about the system, and then add to this understanding additional information they encounter about the system before ultimately subtracting non-relevant information and settling in on a final representation. The latter has been seen with SBF type models in the undergraduate classroom as well (Dauer et al, 2013).…”

Scientific Process Flowchart Assessment (SPFA): A Method for Evaluating Changes in Understanding and Visualization of the Scientific Process in a Multidisciplinary Student Population

“…Knowledge is represented in cognitive structures, or schema. These structures can change to accommodate new knowledge through the process of accretion, wherein new information is added to the existing cognitive structure without significantly changing the cognitive structure (Ifenthaler, 2010; Ifenthaler et al , 2011; Dauer et al , 2013; Speth et al , 2014). Tuning is the alteration of single components in a cognitive structure.…”

A framework for understanding the characteristics of complexity in biology

“…The process of air moving in and out of the lungs is a continuous, interactive, simultaneous, and dynamic set of processes. SBF representations, like student-created models, are limiting in that the nature of some processes cannot easily be represented in the models frequently used to elicit learners' mental models of the systems (Dauer et al 2013;Hmelo-Silver et al 2007). For example, representing the diffusion of oxygen and carbon dioxide across a capillary wall in a lung as a simultaneous (not sequential) process is challenging in a static drawing unless the learner specifically reports this process as simultaneous.…”

“…One example is the structures-behaviorfunction (SBF) framework that has been used to both support and research students' systems thinking (Bray-Speth et al 2014;Dauer et al 2013;Hmelo-Silver et al 2007; Table 1 Dimensions of complexity (right column), taken and adapted from Feltovich et al (2004), organized into components, functional relationships, etc. The middle column represents the potential reductive tendencies that affect learners' reasoning about complex biological systems (Spiro et al 1988) Sequential: process have steps that occur in serial.…”

“…Constructed models (from question prompts targeting specific dimensions) may provide critical information about some dimensions, for example, heterogeneous components, simultaneous processes, or non-linear functional relationships (Bray-Speth et al 2014;Dauer et al 2013;Liu & Hmelo-Silver 2009). For example, in a recent semester, introductory biology students at our university constructed conceptual models of gene regulation of expression and struggled to represent simultaneous events in the lac operon system (JT Dauer, unpublished data).…”