This lesson used the correspondence of Charles Darwin as an exploration of nature of science (NOS) in a historical context. Specifically, we used his original correspondence about his “provisional hypothesis” of pangenesis as a novel way to explore a scientist's social community. Darwin's community of friends and colleagues in the natural sciences at the time of his writing of his 1868 book Variations formed the basis of this lesson. One basic descriptor of NOS, science as a human endeavor, was used to drive explicit reflection. These letters were rich in detail regarding the idea of science as a community of practice. Our elementary education students' responses indicate the letters surprised them in how personal the correspondents were with one another and how reliant Darwin was on his friends and colleagues for input on his work. Darwin became human as students imagined Darwin's mental state and how he wrestled with his idea and made it public. Students learned that despite Darwin's fame, his idea of pangenesis lacked empirical evidence and thus received little support. They discovered an eminent scientist who was insecure and nervous and who worked hard to develop, study, and publicize his novel idea. This contrasts with popular views of major scientific figures as natural geniuses rather than their success resulting from labor and perseverance.

When students think of evolution, they might imagine T. rex, or perhaps an abiotic scene of sizzling electrical storms and harsh reducing atmospheres, an Earth that looks like a lunar landscape. Natural selection automatically elicits responses that include “survival of the fittest,” and “descent with modification,” and with these historical biological catch phrases, one conjures up images of large animals battling it out on the Mesozoic plane. Rarely do teachers or students apply these same ideas to cancer and the evolution of somatic cells, which have accrued mutations and epigenetic imprinting and relentlessly survive and proliferate. Our questions in this paper include the following: Can cancer become an important teaching model for students to explore fundamental hypotheses about evolutionary process? Can the multistep somatic cancer model encourage visualizations that enable students to revisit and reenter previous primary concepts in general biology such as the cell, mitosis, chromosomes, genetic diversity, ecological diversity, immune function, and of course evolution, continually integrating their biology knowledge into process and pattern knowledge? Can the somatic cancer model expose similar patterns and protagonists, linking Darwinian observations of the natural world to our body? And, can the cancer clone model excite critical thinking and student hypotheses about what cancer is as a biological process? Does this visually simple model assist students in recognizing patterns, connecting their biological curriculum dots into a more coherent learning experience? These biological dynamics and intercepting aptitudes of cells are amplified through the cancer model and can help shape the way biology students begin to appreciate the interrelatedness of all biological systems while they continue to explore pivotal points of biological fuzziness, such as the microbiome, limitations of models, and the complex coordination of genomic networks required for the function of even a single cell and the realization of phenotypes.

In this paper we use clonal evolution of cancer as a model experience for students to recreate how a single, non-germline cell appears to shadow the classic pattern of natural selection in body cells that have gone awry. With authentic STEAM activities students can easily crossover and revisit previous biological topics and the ubiquitous nature of natural selection as seen in the example of somatic cells that result in a metastasizing tumor, giving students insight into natural selection's accommodating and tractable patterns throughout the planet.

Phylogenetic tree diagrams are commonly found in introductory biology curricula and represent the evolutionary relationships of organisms. Tree-thinking, or the ability to accurately interpret, use, and generate these phylogenetic representations, involves a challenging set of skills for students to learn. Although many introductory biology courses incorporate tree-thinking instruction, few studies have identified which instructional methods provide the best learning gains for students. We gathered data from 884 introductory biology students using the Basic Evolutionary Tree-Thinking Skills Inventory (BETTSI) to measure tree-thinking learning gains. We measured tree-thinking differences across five sections of introductory biology, each offering a different instructional intervention, and compared differences among STEM majors and non-STEM majors. After calculating paired differences, we performed a two-way repeated measure analysis of variance (ANOVA) and Scheffe's post hoc test to identify significant differences among and between the different interventions. We found that students who engaged in active tree-thinking instruction had significantly higher tree-thinking learning gains than students who participated in passive or no instruction. Furthermore, these learning gains became even more significant as active-learning became more multifaceted. These active-learning approaches also removed knowledge gaps between STEM majors and non-majors. Instructors must select explicit and active pedagogical approaches to support student tree-thinking to accomplish positive learning gains for all students.

Students with religious beliefs often find it difficult to accept the theory of evolution. It is important that educators feel comfortable addressing student questions on the compatibility of evolution and religion. We designed an online professional development course that taught the foundational principles of both evolution and religion in order to assist secular and non-secular educators in helping their students overcome religious barriers to evolution. This course increased the confidence of science educators to help students resolve perceived conflict between evolution and religion. Utilizing a reconciliation model will help religious educators drive science acceptance.

Evolutionary theory is fundamental to biology, yet evolution instruction in high schools has often been unsatisfactory. How or whether high school biology teachers teach evolution is influenced by their own acceptance or rejection of evolutionary theory, parents' and community members' views, and in the case of some private schools, their religious affiliations. Studies documenting how evolution is taught in public high schools have been conducted, yet private schools remain underresearched.

Arkansas high school biology teachers employed by public and private schools were invited to complete a survey composed of the Measure of Acceptance of the Theory of Evolution (MATE) and other items designed to allow comparison of their treatment of topics within evolutionary theory. Specifically, we sought to compare public and private teachers' acceptance of evolution, how they teach it in their classrooms, and how their acceptance of the validity of evolution compares with four other widely accepted scientific theories (cell, gene, germ, and atomic). Results suggest that public school teachers have higher levels of acceptance of evolution than private school teachers. However, teachers in both public and private schools reported lower acceptance of the validity of evolutionary theory compared with the other four scientific theories. Across topics within evolution, natural selection was given the most treatment while human evolution was given the least.

Evolutionary theory is foundational to the life sciences because it unifies complex ecological principles and explains variation observed between and within species. Students at the secondary level often lack deep conceptual understanding of evolutionary theory, which is crucial to grasp topics related to primary drivers within populations such as inter- and intra-specific competition, predation, and reproductive success. Nonetheless, evolution remains a contentious topic in the United States. The prevalence of pseudoscientific belief among the U.S. populace warrants a calculated approach to deconstructing student misconceptions. This article puts forth an action-research-supported instructional strategy through which educators can identify and address core student misconceptions regarding evolutionary theory and other complex scientific phenomena, utilizing real-world and student-generated models to drive instruction.

Understanding that evolution progresses through generation of DNA variants followed by selection is a key learning outcome for biology students. We designed an integrated and innovative undergraduate laboratory exercise using Saccharomyces cerevisiae to demonstrate these principles. Students perform in vitro experimental evolution by repeatedly propagating large or small yeast colonies on a weekly basis. Small-colony variants known as petites arise by mutations that disrupt aerobic respiration. To demonstrate the effects of increased mutation rates, half of the selection lines are exposed to ultraviolet irradiation. To understand how the petite phenotype arises, polymerase chain reaction (PCR) is performed to examine mitochondrial DNA, while biochemical assays are used to assess the ability of petites to undergo aerobic respiration. This exercise demonstrates evolution by artificial selection over a suitably short timeframe and links the results to a critical biochemical process: the role of mitochondria in aerobic respiration and ATP production. By implementing these experiments, we successfully demonstrated that the frequencies of petite mutants in evolved populations varied according to the selection pressure we applied, and that petite mutants carried deletions in mitochondrial DNA as anticipated. Through an integrated learning context, this practical exercise promotes fundamental understanding of evolutionary processes and fosters critical thinking skills.

Computer modeling and protein structure visualization tools are effective and engaging ways of presenting various molecular biology concepts to high school and college students. Here, we describe a series of activities and exercises that use online bioinformatics databases and programs to search for and obtain protein sequence and structure data and use it to build homology models of proteins. Exercises in homology modeling can serve the pedagogical purpose of introducing and illustrating the concept of homology within gene and protein families, which results in conservation of the 3D structures of proteins and allows us to predict structures when experimental data are not available.